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Statement Of Financial Position Unclassified - Real Estate Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2008
ASSETS
Real estate, at cost:	$ 10,659,412	$ 10,185,061
Less: accumulated depreciation	(2,000,917)	(1,744,248)
Total real estate	8,658,495	8,440,813
Cash and cash equivalents	1,448,933	241,510
Cash held in escrows	21,867	21,970
Investment in securities	9,946	11,590
Tenant and other receivables (net of allowance for doubtful accounts of $4,125 and $4,006, respectively)	93,240	68,743
Related party note receivable	270,000	270,000
Accrued rental income (net of allowance of $2,645 and $15,440, respectively)	363,121	316,711
Deferred charges, net	294,395	325,369
Prepaid expenses and other assets	17,684	22,401
Investments in unconsolidated joint ventures	763,636	782,760
Total assets	11,941,317	10,501,867
Liabilities:
Mortgage notes payable, net	2,643,301	2,660,642
Unsecured senior notes (net of discount of $2,611 and $2,625, respectively)	2,172,389	1,472,375
Unsecured exchangeable senior notes (net of discount of $15,529 and $21,101, respectively)	1,904,081	1,859,867
Unsecured line of credit	0	100,000
Accounts payable and accrued expenses	220,089	171,791
Distributions payable	80,536	97,162
Accrued interest payable	76,058	67,132
Other liabilities	127,538	173,750
Total liabilities	$ 7,223,992	$ 6,602,719
Commitments and contingencies	-	-
Noncontrolling interests:
Redeemable partnership units-1,113,044 preferred units outstanding (1,460,688 common units at redemption value, if converted) at December 31, 2009 and December 31, 2008	$ 97,968	$ 80,338
Redeemable partnership units-19,814,499 and 19,909,070 common units and 1,416,162 and 946,509 long term incentive units outstanding at redemption value at December 31, 2009 and December 31, 2008, respectively	1,431,666	1,147,057
Capital:
Boston Properties Limited Partnership partners' capital-1,601,107 and 1,420,362 general partner units and 137,278,903 and 119,760,293 limited partner units outstanding at December 31, 2009 and December 31, 2008, respectively	3,182,020	2,664,853
Noncontrolling interests in property partnerships	5,671	6,900
Total capital	3,187,691	2,671,753
Total liabilities and capital	$ 11,941,317	$ 10,501,867

Statement Of Financial Position Unclassified - Real Estate Operations (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2009	Dec. 31, 2008
Statement [Line Items]
Tenant and other receivables, allowance for doubtful accounts	$ 4,125	$ 4,006
Accrued rental income, allowance	2,645	15,440
Unsecured senior notes, discount	2,611	2,625
Unsecured exchangeable senior notes, discount	$ 15,529	$ 21,101
Redeemable partnership units, preferred units outstanding	1,113,044	1,113,044
Redeemable partnership units, common units at redemption value, if converted	1,460,688	1,460,688
Redeemable partnership units, common units	19,814,499	19,909,070
Redeemable partnership units, long term incentive units outstanding at redemption value	1,416,162	946,509
Boston Properties Limited Partnership partners' capital, general partner units outstanding	1,601,107	1,420,362
Boston Properties Limited Partnership partners' capital, limited partner units outstanding	137,278,903	119,760,293

Statement Of Income Real Estate Investment Trusts - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Rental:
Base rent	$ 1,185,431	$ 1,129,215	$ 1,084,308
Recoveries from tenants	200,899	204,732	184,929
Parking and other	66,597	68,105	64,982
Total rental revenue	1,452,927	1,402,052	1,334,219
Hotel revenue	30,385	36,872	37,811
Development and management services	34,878	30,518	20,553
Interest and other	4,059	18,958	89,706
Total revenue	1,522,249	1,488,400	1,482,289
Operating:
Rental	501,799	488,030	455,840
Hotel	23,966	27,510	27,765
General and administrative	75,447	72,365	69,882
Interest	322,833	295,322	302,980
Depreciation and amortization	313,458	296,122	278,249
Loss from suspension of development	27,766	0	0
Net derivative losses	0	17,021	0
Losses (gains) from investments in securities	(2,434)	4,604	0
Losses from early extinguishments of debt	510	0	3,417
Total expenses	1,263,345	1,200,974	1,138,133
Income before income (loss) from unconsolidated joint ventures, gains on sales of real estate and other assets, discontinued operations and net income attributable to noncontrolling interests	258,904	287,426	344,156
Income (loss) from unconsolidated joint ventures	12,058	(182,018)	20,428
Gains on sales of real estate and other assets	11,760	33,340	957,406
Income from continuing operations	282,722	138,748	1,321,990
Discontinued operations:
Income from discontinued operations	0	0	7,274
Gains on sales of real estate from discontinued operations	0	0	266,817
Net income	282,722	138,748	1,596,081
Net income attributable to noncontrolling interests:
Noncontrolling interests in property partnerships	(2,778)	(1,997)	(84)
Noncontrolling interest-redeemable preferred units	(3,594)	(4,226)	(10,429)
Net income	$ 276,350	$ 132,525	$ 1,585,568
Basic earnings per common unit attributable to Boston Properties Limited Partnership:
Income from continuing operations	$ 1.83	$ 0.94	$ 9.37
Discontinued operations	0.00	0.00	1.97
Net income	$ 1.83	$ 0.94	$ 11.34
Weighted average number of common units outstanding	151,386	140,336	139,290
Diluted earnings per common unit attributable to Boston Properties Limited Partnership:
Income from continuing operations	$ 1.82	$ 0.94	$ 9.24
Discontinued operations	0.00	0.00	1.94
Net income	$ 1.82	$ 0.94	$ 11.18
Weighted average number of common and common equivalent units outstanding	151,848	141,655	141,231
Amounts attributable to Boston Properties Limited Partnership:
Income from continuing operations	$ 276,350	$ 132,525	$ 1,311,477
Discontinued operations	0	0	274,091
Net income	$ 276,350	$ 132,525	$ 1,585,568

Statement Of Partners Capital - USD ($) $ in Thousands	12 Months Ended
Statement Of Partners Capital - USD ($) $ in Thousands	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Statement [Line Items]
Beginning Balance	$ 2,664,853	$ 1,953,898	$ 915,080
Contributions	853,115	37,729	24,226
Capped call transaction costs		(44,360)
Equity component of unsecured exchangeable senior notes		91,947	80,788
Net income allocable to general and limited partner units	239,228	113,302	1,352,760
Distributions	(290,534)	(326,713)	(1,038,521)
Accumulated other comprehensive loss	2,514	(620)	(22,070)
Unearned compensation	(579)	1,149	1,916
Conversion of redeemable partnership units	3,970	10,906	30,590
Adjustment to reflect redeemable partnership units at redemption value	(290,547)	827,615	609,129
Ending Balance	$ 3,182,020	$ 2,664,853	$ 1,953,898

Statement Of Other Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Statement [Line Items]
Net income	$ 282,722	$ 138,748	$ 1,596,081
Other comprehensive income (loss):
Net effective portion of interest rate contracts	0	(727)	(25,656)
Amortization of interest rate contracts	2,904	2	(212)
Other comprehensive income (loss)	2,904	(725)	(25,868)
Comprehensive income	285,626	138,023	1,570,213
Comprehensive income attributable to noncontrolling interests	(6,372)	(6,223)	(10,513)
Comprehensive income attributable to Boston Properties Limited Partnership	$ 279,254	$ 131,800	$ 1,559,700

Statement Of Cash Flows Indirect Real Estate - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2007
Cash flows from operating activities:
Net income	$ 282,722	$ 138,748	$ 1,596,081
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	313,458	296,122	281,197
Non-cash portion of interest expense	55,664	39,323	28,766
Non-cash compensation expense	26,636	23,106	12,358
Non-cash rental revenue	(3,600)	(2,023)	0
Losses (gains) on investments in securities	(2,434)	4,604	0
Net derivative losses	0	17,021	0
Losses from early extinguishments of debt	10	0	838
Loss from suspension of development	27,766	0	0
(Income) loss from unconsolidated joint ventures	(12,058)	182,018	(20,428)
Distributions of net cash flow from operations of unconsolidated joint ventures	12,676	9,589	7,157
Gains on sales of real estate and other assets	(11,760)	(33,340)	(1,224,223)
Change in assets and liabilities:
Cash held in escrows	103	3,548	(2,564)
Tenant and other receivables, net	1,844	2,663	(1,341)
Accrued rental income, net	(46,410)	(20,001)	(38,303)
Prepaid expenses and other assets	4,717	(2,642)	10,686
Accounts payable and accrued expenses	14,848	5,762	3,833
Accrued interest payable	8,926	12,645	7,046
Other liabilities	(9,452)	(54,023)	5,318
Tenant leasing costs	(46,280)	(57,809)	(34,767)
Total adjustments	334,654	426,563	(964,427)
Net cash provided by operating activities	617,376	565,311	631,654
Cash flows from investing activities:
Acquisitions/additions to real estate	(442,844)	(580,377)	(1,134,870)
Investments in securities	0	0	(22,584)
Proceeds from redemptions of investments in securities	4,078	14,697	0
Net investments in unconsolidated joint ventures	(7,835)	(896,027)	(7,790)
Cash recorded upon consolidation	0	0	3,232
Net proceeds from the sale/financing of real estate placed in escrow	0	0	(161,321)
Net proceeds from the sale/financing of real estate released from escrow	0	161,321	0
Issuance of note receivable	0	(270,000)	0
Proceeds from note receivable	0	123,000	0
Net proceeds from the sales of real estate and other assets	0	127,307	1,897,988
Net cash provided by (used in) investing activities	(446,601)	(1,320,079)	574,655
Cash flows from financing activities:
Borrowings on unsecured line of credit	0	1,391,000	260,000
Repayments of unsecured line of credit	(100,000)	(1,291,000)	(260,000)
Repayments of mortgage notes payable	(125,238)	(603,054)	(1,196,618)
Proceeds from mortgage notes payable	107,929	537,569	1,097,369
Proceeds from unsecured exchangeable senior notes	0	647,046	759,575
Proceeds from unsecured senior notes	699,517	0	0
Proceeds from real estate financing transactions	0	0	1,610
Payments on real estate financing transactions	0	(6,208)	(10,610)
Advance from joint venture partners	0	30,000	0
Repayment of advance from joint venture partners	0	(30,000)	0
Distributions	(357,328)	(1,235,767)	(1,143,470)
Partner contributions	850,624	37,410	23,479
Equity component of unsecured exchangeable senior notes	0	91,947	80,788
Capped call transaction costs	0	(44,360)	0
Contributions from (distributions to) noncontrolling interest holders, net	(4,007)	(20,909)	4,304
Repayment of note payable	(25,000)	0	0
Redemption of noncontrolling interest	0	0	(35,625)
Deferred financing costs	(9,849)	(14,317)	(5,978)
Net cash provided by (used in) financing activities	1,036,648	(510,643)	(425,176)
Net increase (decrease) in cash and cash equivalents	1,207,423	(1,265,411)	781,133
Cash and cash equivalents, beginning of the year	241,510	1,506,921	725,788
Cash and cash equivalents, end of the year	1,448,933	241,510	1,506,921
Supplemental disclosures:
Cash paid for interest	307,059	289,640	300,490
Interest capitalized	48,816	46,286	33,322
Non-cash investing and financing activities:
Additions to real estate included in accounts payable	36,789	18,075	3,827
Mortgage notes payable assumed in connection with the acquisition of real estate	0	0	65,224
Real estate recorded upon consolidation	0	0	120,213
Mortgage notes payable recorded upon consolidation	0	0	79,064
Noncontrolling interest recorded upon consolidation	0	0	19,588
Distributions declared but not paid	80,536	97,162	944,870
Issuance of OP Units in connection with the acquisition of real estate	0	15,000	0
Issuance of OP Units in connection with an investment in an unconsolidated joint venture	0	10,000	0
Conversions of redeemable partnership units to partners' capital	3,970	10,906	30,590
Note receivable issued in connection with the transfer of real estate	0	123,000	0
Issuance of restricted units to employees	$ 22,964	$ 43,536	$ 17,658

Organization and Basis of Presentation

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Organization and Basis of Presentation

1.	Organization and Basis of Presentation

Organization

Boston Properties Limited Partnership (the “Company”), a Delaware limited partnership, is the entity through which Boston Properties, Inc., a self-administered and self-managed real estate investment trust (“REIT”), conducts substantially all of its business and owns (either directly or through subsidiaries) substantially all of its assets. Boston Properties, Inc. is the sole general partner of the Company and at December 31, 2009 owned an approximate 86.0% (84.4% at December 31, 2008) general and limited partnership interest in the Company. Partnership interests in the Company are denominated as “common units of partnership interest” (also referred to as “OP Units”), “long term incentive units of partnership interest” (also referred to as “LTIP Units”) or “preferred units of partnership interest” (also referred to as “Preferred Units”). In addition, in February 2008, the Company issued LTIP Units in connection with the granting to employees of 2008 outperformance awards (also referred to as “2008 OPP Units”). Because the rights, preferences and privileges of 2008 OPP Units differ from other LTIP Units granted to employees as part of the annual compensation process, unless specifically noted otherwise, all references to LTIP Units exclude 2008 OPP Units. For a complete description of the terms of the 2008 OPP Units (See Note 17).

Unless specifically noted otherwise, all references to OP Units exclude units held by Boston Properties, Inc. A holder of an OP Unit may present such OP Unit to the Company for redemption at any time (subject to restrictions agreed upon at the time of issuance of OP Units to particular holders that may restrict such redemption right for a period of time, generally one year from issuance). Upon presentation of an OP Unit for redemption, the Company must redeem such OP Unit for cash equal to the then value of a share of common stock of Boston Properties, Inc. (“Common Stock”). In lieu of a cash redemption, Boston Properties, Inc. may elect to acquire such OP Unit for one share of Common Stock. Because the number of shares of Common Stock outstanding at all times equals the number of OP Units that Boston Properties, Inc. owns, one share of Common Stock is generally the economic equivalent of one OP Unit, and the quarterly distribution that may be paid to the holder of an OP Unit equals the quarterly dividend that may be paid to the holder of a share of Common Stock. An LTIP Unit is generally the economic equivalent of a share of restricted common stock of Boston Properties, Inc. LTIP Units, whether vested or not, will receive the same quarterly per unit distributions as OP Units, which equal per share dividends on Common Stock (See Note 17).

At December 31, 2009, there was one series of Preferred Units outstanding (i.e., Series Two Preferred Units). The Series Two Preferred Units bear a distribution that is set in accordance with an amendment to the partnership agreement of the Company. Preferred Units may also be converted into OP Units at the election of the holder thereof or the Company in accordance with the amendment to the partnership agreement (See Note 11).

All references to the Company refer to Boston Properties Limited Partnership and its consolidated subsidiaries, collectively, unless the context otherwise requires.

Properties

At December 31, 2009, the Company owned or had interests in a portfolio of 146 commercial real estate properties (147 properties at December 31, 2008) (the “Properties”) aggregating approximately 50.5 million net rentable square feet (approximately 49.8 million net rentable square feet at December 31, 2008), including five properties under construction totaling approximately 2.0 million net rentable square feet and structured parking for approximately 37,940 vehicles containing approximately 12.8 million square feet. At December 31, 2009, the Properties consist of:

•

140 office properties, including 120 Class A office properties (including three properties under construction) and 20 Office/Technical properties;

•

one hotel;

•

three retail properties; and

•

two residential properties (both of which are under construction).

The Company owns or controls undeveloped land parcels totaling approximately 510.1 acres. In addition, the Company has a noncontrolling interest in the Boston Properties Office Value-Added Fund, L.P. (the “Value-Added Fund”), which is a strategic partnership with two institutional investors through which the Company has pursued the acquisition of value-added investments in assets within its existing markets. The Company’s investments through the Value-Added Fund are not included in its portfolio information or any other portfolio level statistics. At December 31, 2009, the Value-Added Fund had investments in 26 buildings comprised of an office property in Chelmsford, Massachusetts and office complexes in San Carlos, California and Mountain View, California.

The Company considers Class A office properties to be centrally located buildings that are professionally managed and maintained, that attract high-quality tenants and command upper-tier rental rates, and that are modern structures or have been modernized to compete with newer buildings. The Company considers Office/Technical properties to be properties that support office, research and development, laboratory and other technical uses. Net rentable square feet amounts are unaudited.

Basis of Presentation

Boston Properties, Inc. does not have any other significant assets, liabilities or operations, other than its investment in the Company, nor does it have employees of its own. The Company, not Boston Properties, Inc., executes all significant business relationships. All majority-owned subsidiaries and affiliates over which the Company has financial and operating control and variable interest entities (“VIE”s) in which the Company has determined it is the primary beneficiary are included in the consolidated financial statements. All significant intercompany balances and transactions have been eliminated in consolidation. The Company accounts for all other unconsolidated joint ventures using the equity method of accounting. Accordingly, the Company’s share of the earnings of these joint ventures and companies is included in consolidated net income.

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Summary of Significant Accounting Policies

2.	Summary of Significant Accounting Policies

Reclassifications and Adoption of New Accounting Pronouncements

Certain prior year amounts have been reclassified to conform to the current year presentation. In addition, certain prior year amounts have been revised as a result of the adoption on January 1, 2009 of (1) Accounting Standards Codification (“ASC”) 470-20 “Debt with Conversion and Other Options” (“ASC 470-20”) (formerly known as FASB Staff Position (“FSP”) No. APB 14-1 “Accounting for Convertible Debt Instruments That May Be Settled in Cash upon Conversion (Including Partial Cash Settlement)” (“FSP No. APB 14-1”)) (See Note 8), (2) the guidance included in ASC 810 “Consolidation” (“ASC 810”) (formerly known as SFAS No. 160, “Noncontrolling Interests in Consolidated Financial Statements—an amendment of ARB No. 51” (“SFAS No. 160”)) and ASC 480-10-S99 “Distinguishing Liabilities from Equity” (“ASC 480-10-S99”) (formerly known as EITF Topic No. D-98 “Classification and Measurement of Redeemable Securities” (Amended)) (See Note 11) and (3) the guidance included in ASC 260-10 “Earnings Per Share” (“ASC 260-10”) (formerly known as FSP EITF 03-06-1, “Determining Whether Instruments Granted in Share-Based Payment Transactions are Participating Securities” (“FSP EITF 03-06-1”)) (See Note 15).

Real Estate

Upon acquisitions of real estate, the Company assesses the fair value of acquired tangible and intangible assets (including land, buildings, tenant improvements, “above-” and “below-market” leases, origination costs, acquired in-place leases, other identified intangible assets and assumed liabilities in accordance with guidance included in Accounting Standards Codification (“ASC”) 805 “Business Combinations” (“ASC 805”) (formerly known as Statement of Financial Accounting Standards (“SFAS”) No. 141(R) (“SFAS No. 141(R)”)), and allocates the purchase price to the acquired assets and assumed liabilities, including land at appraised value and buildings as if vacant. The Company assesses and considers fair value based on estimated cash flow projections that utilize discount and/or capitalization rates that it deems appropriate, as well as available market information. Estimates of future cash flows are based on a number of factors including the historical operating results, known and anticipated trends, and market and economic conditions. The fair value of the tangible assets of an acquired property considers the value of the property as if it were vacant. The Company also considers an allocation of purchase price of other acquired intangibles, including acquired in-place leases that may have a customer relationship intangible value, including (but not limited to) the nature and extent of the existing relationship with the tenants, the tenant’s credit quality and expectations of lease renewals. Based on its acquisitions to date, the Company’s allocation to customer relationship intangible assets has been immaterial.

The Company records acquired “above-” and “below-market” leases at their fair value (using a discount rate which reflects the risks associated with the leases acquired) equal to the difference between (1) the contractual amounts to be paid pursuant to each in-place lease and (2) management’s estimate of fair market lease rates for each corresponding in-place lease, measured over a period equal to the remaining term of the lease for above-market leases and the initial term plus the term of any below-market fixed rate renewal options for below- market leases. Other intangible assets acquired include amounts for in-place lease values that are based on the Company’s evaluation of the specific characteristics of each tenant’s lease. Factors to be considered include estimates of carrying costs during hypothetical expected lease-up periods considering current market conditions, and costs to execute similar leases. In estimating carrying costs, the Company includes real estate taxes, insurance and other operating expenses and estimates of lost rentals at market rates during the expected lease-up periods, depending on local market conditions. In estimating costs to execute similar leases, the Company considers leasing commissions, legal and other related expenses.

The Company reviews its long-lived assets used in operations for impairment following the end of each quarter and when there is an event or change in circumstances that indicates an impairment in value. An impairment loss is recognized if the carrying amount of its assets is not recoverable and exceeds its fair value. If such criteria are present, an impairment loss is recognized based on the excess of the carrying amount of the asset over its fair value. The evaluation of anticipated cash flows is highly subjective and is based in part on assumptions regarding future occupancy, rental rates and capital requirements that could differ materially from actual results in future periods. Since cash flows on properties considered to be “long-lived assets to be held and used,” as defined by ASC 360 “Property, Plant and Equipment” (“ASC 360”) (formerly known as SFAS No. 144, “Accounting for the Impairment or Disposal of Long-Lived Assets,” (“SFAS No. 144”)) are considered on an undiscounted basis to determine whether an asset has been impaired, the Company’s established strategy of holding properties over the long term directly decreases the likelihood of recording an impairment loss. If the Company’s strategy changes or market conditions otherwise dictate an earlier sale date, an impairment loss may be recognized and such loss could be material. If the Company determines that impairment has occurred, the affected assets must be reduced to their fair value.

ASC 360 (formerly known as SFAS No. 144) requires that qualifying assets and liabilities and the results of operations that have been sold, or otherwise qualify as “held for sale,” be presented as discontinued operations in all periods presented if the property operations are expected to be eliminated and the Company will not have significant continuing involvement following the sale. The components of the property’s net income that is reflected as discontinued operations include the net gain (or loss) upon the disposition of the property held for sale, operating results, depreciation and interest expense (if the property is subject to a secured loan). The Company generally considers assets to be “held for sale” when the transaction has been approved by Boston Properties, Inc.’s Board of Directors, or a committee thereof, and there are no known significant contingencies relating to the sale, such that the property sale within one year is considered probable. Following the classification of a property as “held for sale,” no further depreciation is recorded on the assets, and the asset is written down to the lower of carrying value or fair market value.

Real estate is stated at depreciated cost. A variety of costs are incurred in the acquisition, development and leasing of properties. The cost of buildings and improvements includes the purchase price of property, legal fees and other acquisition costs. Effective January 1, 2009, under the provisions of ASC 805 (formerly known as SFAS No. 141(R)), the Company was required to expense costs associated with the acquisition of real property such as legal, due diligence and other closing related costs. Costs directly related to the development of properties are capitalized. Capitalized development costs include interest, internal wages, property taxes, insurance, and other project costs incurred during the period of development. After determination is made to capitalize a cost, it is allocated to the specific component of a project that is benefited. Determination of when a development project commences and capitalization begins, and when a development project is substantially complete and held available for occupancy and capitalization must cease, involves a degree of judgment. The Company’s capitalization policy on development properties is guided by ASC 835-20 “Capitalization of Interest” and ASC 970 “Real Estate—General” (formerly known as SFAS No. 34 “Capitalization of Interest Cost” and SFAS No. 67 “Accounting for Costs and the Initial Rental Operations of Real Estate Projects”). The costs of land and buildings under development include specifically identifiable costs. The capitalized costs include pre-construction costs necessary to the development of the property, development costs, construction costs, interest costs, real estate taxes, salaries and related costs and other costs incurred during the period of development. The Company begins the capitalization of costs during the pre-construction period which it defines as activities that are necessary to the development of the property. The Company considers a construction project as substantially completed and held available for occupancy upon the completion of tenant improvements, but no later than one year from cessation of major construction activity. The Company ceases capitalization on the portion (1) substantially completed and (2) occupied or held available for occupancy, and capitalizes only those costs associated with the portion under construction, or (3) if activities necessary for the development of the property have been suspended. Interest costs capitalized for the years ended December 31, 2009, 2008 and 2007 were $48.8 million, $46.3 million and $33.3 million, respectively. Salaries and related costs capitalized for the years ended December 31, 2009, 2008 and 2007 were $7.9 million, $7.8 million and $6.9 million, respectively.

Expenditures for repairs and maintenance are charged to operations as incurred. Significant betterments are capitalized. When assets are sold or retired, their costs and related accumulated depreciation are removed from the accounts with the resulting gains or losses reflected in net income or loss for the period.

The Company computes depreciation and amortization on properties using the straight-line method based on estimated useful asset lives. In accordance with ASC 805 (formerly known as SFAS No. 141(R)), the Company allocates the acquisition cost of real estate to land, building, tenant improvements, acquired “above-” and “below-market” leases, origination costs and acquired in-place leases based on an assessment of their fair value and depreciates or amortizes these assets (or liabilities) over their useful lives. The amortization of acquired “above-” and “below-market” leases and acquired in-place leases is recorded as an adjustment to revenue and depreciation and amortization, respectively, in the Consolidated Statements of Operations.

Depreciation is computed on a straight-line basis over the estimated useful lives of the assets as follows:


Land improvements		25 to 40 years
Buildings and improvements		10 to 40 years
Tenant improvements		Shorter of useful life or terms of related lease
Furniture, fixtures, and equipment		3 to 7 years

Cash and Cash Equivalents

Cash and cash equivalents consist of cash on hand and investments with maturities of three months or less from the date of purchase. The majority of the Company’s cash and cash equivalents are held at major commercial banks which may at times exceed the Federal Deposit Insurance Corporation limit of $250,000. The Company has not experienced any losses to date on its invested cash.

Cash Held in Escrows

Escrows include amounts established pursuant to various agreements for security deposits, property taxes, insurance and other costs.

Investment in Securities

The Company accounts for investments in trading securities at fair value, with gains or losses resulting from changes in fair value recognized currently in earnings. The designation of trading securities is generally determined at acquisition. During the year ended December 31, 2009 and 2008, investment in securities is comprised of an investment in an unregistered money market fund and investments in an account associated with the Company’s deferred compensation plan (See Note 16). In December 2007, the unregistered money market fund suspended cash redemptions by investors; investors could elect in-kind redemptions of the underlying securities or maintain their investment in the fund and receive distributions as the underlying securities matured or were liquidated by the fund sponsor. As a result, the Company retained this investment for a longer term than originally intended, and the valuation of the Company’s investment was subject to changes in market conditions. Because interests in this fund were valued at less than their $1.00 par value, the Company recognized gains (losses) of approximately $0.2 million, $(1.4) million and $(0.3) million on its investment during the years ended December 31, 2009, 2008 and 2007, respectively. As of December 31, 2009, the Company no longer had investments in this unregistered money market fund.

The Company also maintains a deferred compensation plan that is designed to allow officers of the Company to defer a portion of their current income on a pre-tax basis and receive a tax-deferred return on these deferrals. The Company’s obligation under the plan is that of an unsecured promise to pay the deferred compensation to the plan participants in the future. At December 31, 2009 and 2008, the Company has funded approximately $9.9 million and $6.6 million, respectively, into a separate account, which is not restricted as to its use. The Company recognized gains (losses) of approximately $2.2 million, $(3.2) million and $0.3 million on its investments in the account associated with the Company’s deferred compensation plan during the years ended December 31, 2009, 2008 and 2007, respectively.

Tenant and other receivables

Tenant and other accounts receivable, other than accrued rents receivable, are expected to be collected within one year.

Deferred Charges

Deferred charges include leasing costs and financing fees. Leasing costs include an allocation for acquired intangible in-place lease values and direct and incremental fees and costs incurred in the successful negotiation of leases, including brokerage, legal, internal leasing employee salaries and other costs which have been deferred and are being amortized on a straight-line basis over the terms of the respective leases. Internal leasing salaries and related costs capitalized for the years ended December 31, 2009, 2008 and 2007 were $3.3 million, $4.4 million and $4.1 million, respectively. External fees and costs incurred to obtain long-term financing have been deferred and are being amortized over the terms of the respective loans on a basis that approximates the effective interest method and are included with interest expense. Unamortized financing and leasing costs are charged to expense upon the early repayment or significant modification of the financing or upon the early termination of the lease, respectively. Fully amortized deferred charges are removed from the books upon the expiration of the lease or maturity of the debt.

Investments in Unconsolidated Joint Ventures

Except for ownership interests in variable interest entities for which the Company is the primary beneficiary, the Company accounts for its investments in joint ventures under the equity method of accounting because it exercises significant influence over, but does not control, these entities. The Company’s judgment with respect to its level of influence or control of an entity and whether it is the primary beneficiary of a variable interest entity involves the consideration of various factors including the form of the Company’s ownership interest, its representation in the entity’s governance, the size of its investment (including loans), estimates of future cash flows, its ability to participate in policy making decisions and the rights of the other investors to participate in the decision making process and to replace the Company as manager and/or liquidate the venture, if applicable. The Company’s assessment of its influence or control over an entity affects the presentation of these investments in the Company’s consolidated financial statements.

These investments are recorded initially at cost, as Investments in Unconsolidated Joint Ventures, and subsequently adjusted for equity in earnings and cash contributions and distributions. Any difference between the carrying amount of these investments on the balance sheet and the underlying equity in net assets is amortized as an adjustment to equity in earnings of unconsolidated joint ventures over the life of the related asset. Under the equity method of accounting, the net equity investment of the Company is reflected within the Consolidated Balance Sheets, and the Company’s share of net income or loss from the joint ventures is included within the Consolidated Statements of Operations. The joint venture agreements may designate different percentage allocations among investors for profits and losses, however, the Company’s recognition of joint venture income or loss generally follows the joint venture’s distribution priorities, which may change upon the achievement of certain investment return thresholds. For ownership interests in variable interest entities, the Company consolidates those in which it is the primary beneficiary. The Company’s investments in unconsolidated joint ventures are reviewed for impairment periodically and the Company records impairment charges when events or circumstances change indicating that a decline in the fair values below the carrying values has occurred and such decline is other-than-temporary. The ultimate realization of the investment in unconsolidated joint ventures is dependent on a number of factors, including the performance of each investment and market conditions. The Company will record an impairment charge if it determines that a decline in the value of an investment in an unconsolidated joint venture is other than temporary.

To the extent that the Company contributes assets to a joint venture, the Company’s investment in the joint venture is recorded at the Company’s cost basis in the assets that were contributed to the joint venture. To the extent that the Company’s cost basis is different than the basis reflected at the joint venture level, the basis difference is amortized over the life of the related asset and included in the Company’s share of equity in net income of the joint venture. In accordance with the provisions of ASC 970-323 “Investments—Equity Method and Joint Ventures” (“ASC 970-323”) (formerly Statement of Position 78-9 “Accounting for Investments in Real Estate Ventures” (“SOP 78-9”)), the Company will recognize gains on the contribution of real estate to joint ventures, relating solely to the outside partner’s interest, to the extent the economic substance of the transaction is a sale.

Revenue Recognition

Contractual rental revenue is reported on a straight-line basis over the terms of the respective leases. The impact of the straight-line rent adjustment increased revenue by approximately $42.2 million, $24.5 million and $39.1 million for the years ended December 31, 2009, 2008 and 2007, respectively, as the revenue recorded exceeded amounts billed. The straight-line rent adjustment for the year ended December 31, 2008 includes an approximately $21.0 million decrease due to the establishment of reserves for the full amount of the accrued straight-line rent balances associated with two of the Company’s leases in New York City. In accordance with ASC 805 (formerly SFAS No. 141(R)), the Company recognizes rental revenue of acquired in-place “above-” and “below-market” leases at their fair values over the terms of the respective leases. The impact of the acquired in-place “above-” and “below-market” leases increased revenue by approximately $4.2 million, $5.4 million and $5.9 million for the years ended December 31, 2009, 2008 and 2007, respectively. Accrued rental income, as reported on the Consolidated Balance Sheets, represents cumulative rental income earned in excess of rent payments received pursuant to the terms of the individual lease agreements. The Company maintains an allowance against accrued rental income for future potential tenant credit losses. The credit assessment is based on the estimated accrued rental income that is recoverable over the term of the lease. The Company also maintains an allowance for doubtful accounts for estimated losses resulting from the inability of tenants to make required rent payments. The computation of this allowance is based on the tenants’ payment history and current credit status, as well as certain industry or geographic specific credit considerations. If the Company’s estimates of collectibility differ from the cash received, then the timing and amount of the Company’s reported revenue could be impacted. The credit risk is mitigated by the high quality of the Company’s existing tenant base, reviews of prospective tenants’ risk profiles prior to lease execution and consistent monitoring of the Company’s portfolio to identify potential problem tenants.

Recoveries from tenants, consisting of amounts due from tenants for common area maintenance, real estate taxes and other recoverable costs are recognized as revenue in the period during which the expenses are incurred. Tenant reimbursements are recognized and presented in accordance with ASC 605-45 “Principal Agent Considerations” (“ASC 605-45”) (formerly known as Emerging Issues Task Force, or EITF, Issue 99-19 “Reporting Revenue Gross as a Principal versus Net as an Agent,” or (“Issue 99-19”)). ASC 605-45 requires that these reimbursements be recorded on a gross basis, as the Company is generally the primary obligor with respect to purchasing goods and services from third- party suppliers, has discretion in selecting the supplier and has credit risk. The Company also receives reimbursement of payroll and payroll related costs from third parties which the Company reflects on a net basis in accordance with ASC 605-45.

The Company’s hotel revenues are derived from room rentals and other sources such as charges to guests for long-distance telephone service, fax machine use, movie and vending commissions, meeting and banquet room revenue and laundry services. Hotel revenues are recognized as earned.

The Company receives management and development fees from third parties. Management fees are recorded and earned based on a percentage of collected rents at the properties under management, and not on a straight-line basis, because such fees are contingent upon the collection of rents. The Company reviews each development agreement and records development fees as earned depending on the risk associated with each project. Profit on development fees earned from joint venture projects is recognized as revenue to the extent of the third party partners’ ownership interest.

Gains on sales of real estate are recognized pursuant to the provisions of ASC 360-20 “Real Estate Sales” (“ASC 360-20”) (formerly known as SFAS No. 66, “Accounting for Sales of Real Estate” (“SFAS No. 66”)). The specific timing of a sale is measured against various criteria in ASC 360-20 related to the terms of the transaction and any continuing involvement in the form of management or financial assistance associated with the properties. If the sales criteria for the full accrual method are not met, the Company defers some or all of the gain recognition and accounts for the continued operations of the property by applying the finance, leasing, profit sharing, deposit, installment or cost recovery methods, as appropriate, until the sales criteria are met.

Earnings Per Common Unit

Basic earnings per common unit is computed by dividing net income available to common unitholders, as adjusted for unallocated earnings (if any) of certain securities issued by the Company, by the weighted average number of common units outstanding during the year. Diluted earnings per common unit reflects the potential dilution that could occur from units issuable under Boston Properties, Inc.’s stock-based compensation plans, including upon the exercise of stock options, and conversion of preferred units of the Company.

Fair Value of Financial Instruments

The carrying values of cash and cash equivalents, marketable securities, escrows, receivables, accounts payable, accrued expenses and other assets and liabilities are reasonable estimates of their fair values because of the short maturities of these instruments.

In April 2009, the FASB issued ASC 825-10-65 “Transition Related to FSP FAS 107-1 and APB 28-1, Interim Disclosures about Fair Value of Financial Instruments” (“ASC 825-10-65”) (formerly known as FSP No. FAS 107-1 and APB 28-1, “Interim Disclosures about Fair Value of Financial Instruments” (“FSP No. FAS 107-1”)). ASC 825-10-65 requires disclosures about fair-value of financial instruments for interim reporting periods of publicly-traded companies as well as in annual financial statements. ASC 825-10-65 requires those disclosures in summarized financial information at interim reporting periods. ASC 825-10-65 was effective for interim reporting periods ending after June 15, 2009, with early adoption permitted for periods ending after March 15, 2009. For purposes of financial reporting disclosures, the Company calculates the fair value of mortgage notes payable, unsecured senior notes and unsecured exchangeable senior notes. The Company discounts the spread between the future contractual interest payments and hypothetical future interest payments on mortgage debt and unsecured notes based on a current market rate. In determining the current market rate, the Company adds its estimation of a market spread to the quoted yields on federal government treasury securities with similar maturity dates to its debt. Because the Company’s valuations of its financial instruments are based on these types of estimates, the actual fair value of its financial instruments may differ materially if the Company’s estimates do not prove to be accurate. The following table presents the aggregate carrying value of the Company’s indebtedness and the Company’s corresponding estimate of fair value as of December 31, 2009 (in thousands):


	Carrying Amount			Estimated Fair Value
Mortgage notes payable	$	2,643,301		$	2,615,099
Unsecured senior notes		2,172,389			2,318,868
Unsecured exchangeable senior notes		1,904,081	(1)		2,059,796

Total	$	6,719,771		$	6,993,763

(1)	Includes the net impact of ASC 470-20 (formerly known as FSP No. APB 14-1) totaling approximately $140.4 million (See Note 8).

Derivative Instruments and Hedging Activities

Derivative instruments and hedging activities require management to make judgments on the nature of its derivatives and their effectiveness as hedges. These judgments determine if the changes in fair value of the derivative instruments are reported in the consolidated statements of operations as a component of net income or as a component of comprehensive income and as a component of equity on the consolidated balance sheets. While management believes its judgments are reasonable, a change in a derivative’s effectiveness as a hedge could materially affect expenses, net income and equity. The Company recognized net derivative losses of approximately $17.0 million for the year ended December 31, 2008 within the caption Net Derivative Losses in the Consolidated Statements of Operations.

Income Taxes

The partners are required to report their respective share of the Company’s taxable income or loss on their respective tax returns and are liable for any related taxes thereon. Accordingly, the only provision for federal income taxes in the accompanying consolidated financial statements relates to the Company’s consolidated taxable REIT subsidiaries. The Company’s taxable REIT subsidiaries did not have significant tax provisions or deferred income tax items.

The company owns a hotel property which is managed through a taxable REIT subsidiary. The hotel taxable REIT subsidiary, a wholly owned subsidiary of the Company, is the lessee pursuant to the lease for the hotel property. As lessor, the Company is entitled to a percentage of gross receipts from the hotel property. Marriott International, Inc. continues to manage the hotel property under the Marriott name and under terms of the existing management agreements. In connection with the restructuring, the revenue and expenses of the hotel property are being reflected in the Company’s Consolidated Statements of Operations. The hotel taxable REIT subsidiary is subject to tax at the federal and state level and, accordingly, the Company has recorded a tax provision in the Company’s Consolidated Statements of Operations for the years ended December 31, 2009, 2008 and 2007.

The net difference between the tax basis and the reported amounts of the Company’s assets and liabilities is approximately $1.1 billion and $0.9 billion as of December 31, 2009 and 2008, respectively, which is primarily related to the difference in basis of contributed property and accrued rental income.

Certain entities included in the Company’s consolidated financial statements are subject to certain state and local taxes. These taxes are recorded as operating expenses in the accompanying consolidated financial statements.

The following reconciles GAAP net income attributable to Boston Properties Limited Partnership to taxable income:


	For the year ended December 31,
	2009			2008			2007
	(in thousands)
Net income attributable to Boston Properties Limited Partnership	$	276,350		$	132,525		$	1,585,568
Straight-line rent adjustments		(44,529	)		(24,025	)		(43,531	)
Book/Tax differences from depreciation and amortization		56,276			87,565			49,813
Book/Tax differences on gains/losses from capital transactions		(11,760	)		(33,340	)		(356,606	)
Book/Tax differences from stock-based compensation		18,568			(22,695	)		(52,109	)
Impairment loss on investments in unconsolidated joint ventures		7,413			188,325			—
Other book/tax differences, net		13,503			39,158			12,032

Taxable income	$	315,821		$	367,513		$	1,195,167

Stock-based employee compensation plans

At December 31, 2009, Boston Properties, Inc. has a stock-based employee compensation plan. Effective January 1, 2005, the Company adopted early ASC 718 “Compensation—Stock Compensation” (“ASC 718”) (formerly SFAS No. 123 (revised) (“SFAS No. 123R”), “Share-Based Payment”), which revised the fair value based method of accounting for share-based payment liabilities, forfeitures and modifications of stock-based awards and clarified previous guidance in several areas, including measuring fair value, classifying an award as equity or as a liability and attributing compensation cost to reporting periods.

Use of Estimates in the Preparation of Financial Statements

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. These estimates include such items as depreciation and allowances for doubtful accounts. Actual results could differ from those estimates.

Real Estate

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Real Estate

3.	Real Estate

Real estate consisted of the following at December 31 (in thousands):


	2009			2008
Land	$	1,874,004		$	1,867,429
Land held for future development		714,620			224,395
Buildings and improvements		6,561,240			6,372,010
Tenant improvements		922,224			862,315
Furniture, fixtures and equipment		23,679			22,929
Development in process		563,645			835,983

Total		10,659,412			10,185,061
Less: Accumulated depreciation		(2,000,917	)		(1,744,248	)

	$	8,658,495		$	8,440,813

Development

On January 16, 2009, the Company acquired the development rights for the site at 17 Cambridge Center in Cambridge, Massachusetts for approximately $11.4 million. On November 6, 2009, the Company acquired the land parcel at 17 Cambridge Center in Cambridge, Massachusetts for a gross purchase price of approximately $6.0 million.

On February 6, 2009, the Company announced that it was suspending construction on its 1,000,000 square foot office building at 250 West 55th Street in New York City. During December 2009, the Company completed the construction of foundations and steel/deck to grade to facilitate a restart of construction in the future and as a result ceased interest capitalization on the project. During the year ended December 31, 2009, the Company recognized a loss of approximately $27.8 million related to the suspension of development (See Note 22).

On April 1, 2009, the Company placed in-service One Preserve Parkway, an approximately 183,000 net rentable square foot Class A office property located in Rockville, Maryland. The property is 65% leased.

On May 31, 2009, a consolidated joint venture in which the Company has a 66.67% interest placed in-service the Offices at Wisconsin Place, an approximately 299,000 net rentable square foot Class A office property located in Chevy Chase, Maryland. The property is 91% leased.

On August 1, 2009, the Company placed in-service Democracy Tower, an approximately 235,000 net rentable square foot Class A office property located in Reston, Virginia. The property is 100% leased.

On October 9, 2009, the Company placed in-service 701 Carnegie Center, an approximately 120,000 net rentable square foot Class A office property located in Princeton, New Jersey. The property is 100% leased.

Dispositions

On April 14, 2008, the Company sold a parcel of land located in Washington, DC for approximately $33.7 million. The Company had previously entered into a development management agreement with the buyer to develop a Class A office property on the parcel totaling approximately 165,000 net rentable square feet. Due to the Company’s involvement in the construction of the project, the gain on sale was deferred and is being recognized over the project construction period generally based on the percentage of total project costs incurred to estimated total project costs. As a result, the Company recognized a gain on sale during the year ended December 31, 2009 of approximately $11.8 million. The Company has recognized a cumulative gain on sale of approximately $21.7 million.

Deferred Charges

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Deferred Charges

4.	Deferred Charges

Deferred charges consisted of the following at December 31, (in thousands):


	2009			2008
Leasing costs (and lease related intangibles)	$	399,302		$	416,299
Financing costs		76,915			67,594

		476,217			483,893
Less: Accumulated amortization		(181,822	)		(158,524	)

	$	294,395		$	325,369

Investments in Unconsolidated Joint Ventures

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Investments in Unconsolidated Joint Ventures

5.	Investments in Unconsolidated Joint Ventures

The investments in unconsolidated joint ventures consists of the following at December 31, 2009:


Entity	Properties	Nominal % Ownership
Square 407 Limited Partnership	Market Square North	50.0	%
The Metropolitan Square Associates LLC	Metropolitan Square	51.0	%(1)
BP/CRF 901 New York Avenue LLC	901 New York Avenue	25.0	%(2)
WP Project Developer LLC	Wisconsin Place Land and Infrastructure	23.9	%(3)
Wisconsin Place Retail LLC	Wisconsin Place Retail	5.0	%
Eighth Avenue and 46^th Street Entities	Eighth Avenue and 46^th Street	50.0	%(4)
Boston Properties Office Value-Added Fund, L.P.	300 Billerica Road, One & Two Circle Star Way and Mountain View Research and Technology Parks	36.9	%(2)(5)
Annapolis Junction NFM, LLC	Annapolis Junction	50.0	%(6)
767 Venture, LLC	The General Motors Building	60.0	%(1)
2 GCT Venture LLC	Two Grand Central Tower	60.0	%(1)
540 Madison Venture LLC	540 Madison Avenue	60.0	%(1)
125 West 55^th Street Venture LLC	125 West 55^th Street	60.0	%(1)

(1)	The Company has determined that these entities are not VIEs and that its joint venture partners have substantive participating rights with respect to the assets and operations of the properties, pursuant to the joint venture agreements.

(2)	The Company’s economic ownership can increase based on the achievement of certain return thresholds.

(3)	Represents the Company’s effective ownership interest. The Company has a 66.67%, 5% and 0% interest in the office, retail and residential joint venture entities, respectively, each of which owns a 33.33% interest in owning the land and infrastructure of the project.

(4)	This property is not in operation and consists of assembled land.

(5)	Represents the Company’s effective ownership interest. The Company has a 25.0% interest in the 300 Billerica Road and One & Two Circle Star Way properties and a 39.5% interest in the Mountain View Research and Technology Park properties.

(6)	Two of the three Annapolis Junction land parcels are undeveloped land.

Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures at an agreed upon fair value. Under these provisions, the Company is not compelled to purchase the interest of its outside joint venture partners.

During 2009, the Company recognized non-cash impairment charges which represented the other-than-temporary decline in the fair value below the carrying value of the Company’s investment in its Value-Added Fund. In accordance with ASC 323 “Investments-Equity Method and Joint Ventures” (“ASC 323”) (formerly known as Accounting Principles Board Opinion No. 18 “The Equity Method of Accounting for Investments in Common Stock” (“APB No. 18”)), a loss in value of an investment under the equity method of accounting, which is other than a temporary decline, must be recognized. Unlike the guidance in ASC 360 “Property, Plant and Equipment” (“ASC 360”) (formerly known as SFAS No. 144 “Accounting for the Impairment or Disposal of Long Lived Assets”), impairments under ASC 323 result from fair values derived based on discounted cash flows and other valuation techniques that are more sensitive to current market conditions. As a result, the Company recognized a non-cash impairment charge of approximately $9.4 million on its investment in the Company’s Value-Added Fund. The Company has determined that its valuation of these investments was categorized within Level 3 of the fair value hierarchy in accordance with ASC 820-10 “Fair Value Measurements and Disclosures” (“ASC 820-10”) (formerly known as SFAS No. 157, “Fair Value Measurements” (“SFAS No. 157”)), as it utilized significant unobservable inputs in its assessment. The equity method investments represent the Company’s only Level 3 assets for the year ended December 31, 2009. In addition, during December 2009, the Company’s Value-Added Fund recognized a non-cash impairment charge in accordance with the guidance in ASC 360 (formerly known as SFAS No. 144) related to its One and Two Circle Star Way properties in San Carlos, California totaling approximately $24.6 million, of which the Company’s share was approximately $4.2 million, which amount reflects the reduction in the Company’s basis of approximately $2.0 million from previous impairment losses. The One and Two Circle Star Way properties will be vacant by the end of February 2010 and leasing activity continues to be challenging, with market rents declining significantly. The Value-Added Fund has a mortgage loan collateralized by the properties which is non-recourse to the Company and which expires in September 2013 and includes a cash escrow in place to fund the interest expense and carrying costs through mid-2010. The Value-Added Fund is currently in discussions with the lender to modify the loan and as a result believes that the carrying value of the properties may not be recoverable. Accordingly, the Value-Added Fund recognized the non-cash impairment charge to reduce the net book value of the properties to their estimated fair market value at December 31, 2009.

The following table reflects the activity of its investments in unconsolidated joint ventures for the year ended December 31, 2009 (in thousands):


Balance at January 1, 2009:	$	782,760
Net loss		(10,898	)
Impairment losses		(9,385	)
Contributions		11,015
Distributions		(9,856	)

Balance at December 31, 2009:	$	763,636

The combined summarized financial information of the unconsolidated joint ventures is as follows (in thousands):


	December 31,
Balance Sheets	2009			2008
Real estate and development in process, net	$	5,149,868		$	5,235,149
Other assets		760,001			824,232

Total assets	$	5,909,869		$	6,059,381

Mortgage and Notes payable	$	3,217,893		$	3,189,549
Other liabilities		1,071,904			1,215,849
Members’/Partners’ equity		1,620,072			1,653,983

Total liabilities and members’/partners’ equity	$	5,909,869		$	6,059,381

Company’s share of equity	$	927,184		$	948,222
Basis differential (1)		(163,548	)		(165,462	)

Carrying value of the Company’s investments in unconsolidated joint ventures	$	763,636		$	782,760

(1)

This amount represents the aggregate difference between the Company’s historical cost basis and the basis reflected at the joint venture level, which is typically amortized over the life of the related assets and liabilities. Basis differentials occur from impairment of investments and upon the transfer of assets that were previously owned by the Company into a joint venture. In addition, certain acquisition, transaction and other costs may not be reflected in the net assets at the joint venture level.


	Year Ended December 31,
Statements of Operations	2009			2008			2007
	(in thousands)
Total revenue (1)	$	595,533		$	363,168		$	95,064
Expenses
Operating		163,209			101,670			35,546
Interest		232,978			139,154			31,883
Depreciation and amortization		232,047			144,712			21,386
Impairment losses		24,568			40,570			—
Losses from early extinguishments of debt		—			152			146

Total expenses		652,802			426,258			88,961

Income (loss) before gain on sale of real estate		(57,269	)		(63,090	)		6,103
Gain on sale of real estate		—			—			32,777

Net income (loss)	$	(57,269	)	$	(63,090	)	$	38,880

Company’s share of net income (loss)	$	(22,197	)	$	(30,910	)	$	20,428
Impairment losses on investments		(9,385	)		(168,040	)		—
Basis differential		11,299			—			—
Elimination of inter-entity interest on partner loan		32,341			16,932			—

Income (loss) from unconsolidated joint ventures	$	12,058		$	(182,018	)	$	20,428

(1)

Includes straight-line rent adjustments of $28.0 million, $14.9 million and $2.2 million for the years ended December 31, 2009, 2008 and 2007, respectively. Includes “above” and “below” market rent adjustments of $157.5 million, $91.7 million and $(3.2) million for the years ended December 31, 2009, 2008 and 2007, respectively.

Mortgage Notes Payable

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Mortgage Notes Payable

6.	Mortgage Notes Payable

The Company had outstanding mortgage notes payable totaling approximately $2.6 billion and $2.7 billion as of December 31, 2009 and 2008, respectively, each collateralized by one or more buildings and related land included in real estate assets. The mortgage notes payable are generally due in monthly installments and mature at various dates through August 1, 2021.

Fixed rate mortgage notes payable totaled approximately $2.2 billion and $2.4 billion at December 31, 2009 and 2008, respectively, with contractual interest rates ranging from 5.55% to 8.13% per annum at December 31, 2009 and 5.55% to 8.54% per annum at December 31, 2008 (with weighted-averages of 6.45% and 6.50% at December 31, 2009 and 2008, respectively).

Variable rate mortgage notes payable (including construction loans payable) totaled approximately $393.4 million and $285.5 million at December 31, 2009 and 2008, respectively, with interest rates ranging from 1.00% to 3.85% above the London Interbank Offered Rate (“LIBOR”) at December 31, 2009 and ranging from 1.00% to 1.75% above LIBOR at December 31, 2008. As of December 31, 2009 and 2008, the LIBOR rate was 0.23% and 0.44%, respectively.

On April 21, 2009, the Company obtained construction financing totaling $215.0 million collateralized by its Atlantic Wharf development project located at 280 Congress Street in Boston, Massachusetts. Atlantic Wharf, formerly known as Russia Wharf, is a mixed-use project totaling approximately 860,000 net rentable square feet. Wellington Management Company, LLP has leased approximately 450,000 square feet of the office space in the development commencing in the first quarter of 2011. The construction financing bears interest at a variable rate equal to LIBOR plus 3.00% per annum and matures on April 21, 2012 with two, one-year extension options, subject to certain conditions. There were no amounts drawn on the construction facility as of December 31, 2009.

On June 9, 2009, the Company used available cash to repay the mortgage loan collateralized by its Reservoir Place property located in Waltham, Massachusetts totaling approximately $47.8 million. The mortgage loan bore interest at a fixed rate of 7.00% per annum and was scheduled to mature on July 1, 2009. There was no prepayment penalty.

On June 26, 2009, the Company used available cash to repay the mortgage loan collateralized by its Ten Cambridge Center property located in Cambridge, Massachusetts totaling approximately $30.1 million. The mortgage loan bore interest at a fixed rate of 8.27% per annum and was scheduled to mature on May 1, 2010. The Company paid a prepayment penalty totaling $0.5 million in connection with the repayment.

On July 30, 2009, the Company obtained mortgage financing totaling $50.0 million collateralized by its Reservoir Place property located in Waltham, Massachusetts. The mortgage financing currently bears interest at a variable rate equal to LIBOR plus 3.85% per annum and matures on July 30, 2014.

On August 3, 2009, the Company used available cash to repay the mortgage loans collateralized by its 1301 New York Avenue property located in Washington, DC aggregating approximately $20.5 million. The mortgage loans bore interest at a weighted-average fixed rate of 6.91% per annum and were scheduled to mature on August 15, 2009. There were no prepayment penalties.

Six mortgage loans totaling approximately $295.0 million at December 31, 2009 and seven mortgage loans totaling approximately $350.2 million at December 31, 2008 have been accounted for at their fair values on the date the mortgage loans were assumed. The impact of recording the mortgage loans at fair value resulted in a decrease to interest expense of $4.1 million, $4.3 million and $4.2 million for the years ended December 31, 2009, 2008 and 2007, respectively. The cumulative liability related to the fair value adjustments was $9.1 million and $13.2 million at December 31, 2009 and 2008, respectively, and is included in mortgage notes payable in the Consolidated Balance Sheets.

Contractual aggregate principal payments of mortgage notes payable at December 31, 2009 are as follows:


	Principal Payments
	(in thousands)
2010	$	347,382
2011		646,378
2012		105,404
2013		101,263
2014		125,237
Thereafter		1,308,557

Unsecured Senior Notes

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Unsecured Senior Notes

7.	Unsecured Senior Notes

The following summarizes the unsecured senior notes outstanding as of December 31, 2009 (dollars in thousands):


	Coupon/ Stated Rate		Effective Rate(1)		Principal Amount			Maturity Date(2)
10 Year Unsecured Senior Notes	6.250	%	6.381	%	$	750,000		January 15, 2013
10 Year Unsecured Senior Notes	6.250	%	6.291	%		175,000		January 15, 2013
12 Year Unsecured Senior Notes	5.625	%	5.693	%		300,000		April 15, 2015
12 Year Unsecured Senior Notes	5.000	%	5.194	%		250,000		June 1, 2015
10 Year Unsecured Senior Notes	5.875	%	5.967	%		700,000		October 15, 2019

Total principal						2,175,000
Net discount						(2,611	)

Total					$	2,172,389

(1)	Yield on issuance date including the effects of discounts on the notes.

(2)	No principal amounts are due prior to maturity.

On October 9, 2009, the Company completed a public offering of $700.0 million in aggregate principal amount of its 5.875% senior notes due 2019. The notes were priced at 99.931% of the principal amount to yield 5.967% to maturity. The aggregate net proceeds to the Company, after deducting underwriter discounts and offering expenses, were approximately $693.7 million. The notes mature on October 15, 2019, unless earlier redeemed by the Company.

The indenture relating to the unsecured senior notes contains certain financial restrictions and requirements, including (1) a leverage ratio not to exceed 60%, (2) a secured debt leverage ratio not to exceed 50%, (3) an interest coverage ratio of greater than 1.50, and (4) an unencumbered asset value of not less than 150% of unsecured debt. At December 31, 2009 and 2008, the Company was in compliance with each of these financial restrictions and requirements.

Unsecured Exchangeable Senior Notes

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Unsecured Exchangeable Senior Notes

8.	Unsecured Exchangeable Senior Notes

The following summarizes the unsecured exchangeable senior notes outstanding as of December 31, 2009 (dollars in thousands):


	Coupon/ Stated Rate		Effective Rate(1)		Exchange Rate		Principal Amount			First Optional Redemption Date by Company	Maturity Date
3.625% Exchangeable Senior Notes	3.625	%	4.037	%	8.5051	(2)	$	747,500		N/A	February 15, 2014
2.875% Exchangeable Senior Notes	2.875	%	3.462	%	7.0430	(3)		862,500		February 20, 2012	February 15, 2037
3.750% Exchangeable Senior Notes	3.750	%	3.787	%	10.0066	(4)		450,000		May 18, 2013	May 15, 2036

Total principal								2,060,000
Net discount								(15,529	)
ASC 470-20 (formerly known as FSP No. APB 14-1) Adjustment, net of accumulated amortization								(140,390	)

Total							$	1,904,081

(1)	Yield on issuance date including the effects of discounts on the notes and excluding the effects of ASC 470-20 (formerly known as FSP No. APB 14-1).

(2)

The initial exchange rate is 8.5051 shares per $1,000 principal amount of the notes (or an initial exchange price of approximately $117.58 per share of Boston Properties, Inc.’s Common Stock). In addition, the Company entered into capped call transactions with affiliates of certain of the initial purchasers, which are intended to reduce the potential dilution upon future exchange of the notes. The capped call transactions are intended to increase the effective exchange price to the Company of the notes from $117.58 to approximately $137.17 per share, representing an overall effective premium of approximately 40% over the closing price on August 13, 2008 of $97.98 per share of Boston Properties, Inc.’s Common Stock. The net cost of the capped call transactions was approximately $44.4 million.

(3)

In connection with the special distribution of $5.98 per share of Boston Properties, Inc.’s Common Stock declared on December 17, 2007, the exchange rate was adjusted from 6.6090 to 7.0430 shares per $1,000 principal amount of notes effective as of December 31, 2007, resulting in an exchange price of approximately $141.98 per share of Boston Properties, Inc.’s Common Stock.

(4)

In connection with the special distribution of $5.98 per share of Boston Properties, Inc.’s Common Stock declared on December 17, 2007, the exchange rate was adjusted from 9.3900 to 10.0066 shares per $1,000 principal amount of notes effective as of December 31, 2007, resulting in an exchange price of approximately $99.93 per share of Boston Properties, Inc.’s Common Stock.

ASC 470-20 (formerly known as FSP No. APB 14-1) requires the liability and equity components of convertible debt instruments that may be settled in cash upon conversion (including partial cash settlement) to be separately accounted for in a manner that reflects the issuer’s nonconvertible debt borrowing rate. ASC 470-20 requires that the initial proceeds from the sale of the Company’s $862.5 million of 2.875% exchangeable senior notes due 2037, $450.0 million of 3.75% exchangeable senior notes due 2036 and $747.5 million of 3.625% exchangeable senior notes due 2014 be allocated between a liability component and an equity component in a manner that reflects interest expense at the interest rate of similar nonconvertible debt that could have been issued by the Company at such time. The Company measured the fair value of the debt components of the 2.875%, 3.75% and 3.625% exchangeable senior notes for the periods presented based on effective interest rates of 5.630%, 5.958% and 6.555%, respectively. The aggregate carrying amount of the debt component was approximately $1.90 billion and $1.86 billion (net of the ASC 470-20 adjustment of approximately $140.4 million and $179.0 million) at December 31, 2009 and December 31, 2008, respectively. As a result, the Company attributed an aggregate of approximately $230.3 million of the proceeds to the equity component of the notes, which represents the excess proceeds received over the fair value of the notes at the date of issuance. The equity component of the notes has been reflected within Partners’ Capital in the Consolidated Balance Sheets. The Company reclassified approximately $1.0 million of deferred financing costs to Partners’ Capital, which represented the costs attributable to the equity components of the notes. The carrying amount of the equity component was approximately $229.3 million at December 31, 2009 and December 31, 2008. The resulting debt discount will be amortized over the period during which the debt is expected to be outstanding (i.e., through the first optional redemption dates or, in the case of the 2014 notes, the maturity date) as additional non-cash interest expense. The additional non-cash interest expense attributable to each debt security will increase in subsequent reporting periods through the first optional redemption date (or, in the case of the 2014 notes, the maturity date) as the debt accretes to its par value over the same period. The aggregate contractual interest expense was approximately $74.4 million, $56.4 million and $43.1 million for the years ended December 31, 2009, 2008 and 2007, respectively. As a result of applying ASC 470-20, the Company reported additional non-cash interest expense of approximately $38.6 million, $27.8 million and $19.4 million for the years ended December 31, 2009, 2008 and 2007, respectively. ASC 470-20 requires companies to retrospectively apply the requirements of the pronouncement to all periods presented. As a result, the revised diluted earnings per common unit reflect a reduction of $0.16 and $0.12 for the years ended December 31, 2008 and 2007, respectively. The application of ASC 470-20 reduced diluted earnings per common unit by approximately $0.25 for the year ended December 31, 2009.

Unsecured Line of Credit

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Unsecured Line of Credit

9.	Unsecured Line of Credit

On June 6, 2008, the Company utilized an accordion feature under its unsecured revolving credit facility (the “Unsecured Line of Credit”) with a consortium of lenders to increase the current lenders’ total commitment under the Unsecured Line of Credit from $605.0 million to $923.3 million. On July 21, 2008, the Company further increased the total commitment from $923.3 million to $1.0 billion. All other material terms under the facility remain unchanged. The Company’s Unsecured Line of Credit bears interest at a variable interest rate equal to Eurodollar plus 0.475% per annum and matures on August 3, 2010, with a provision for a one-year extension at the option of the Company, subject to certain conditions. The Unsecured Line of Credit is a recourse obligation of the Company. Under the Unsecured Line of Credit, a facility fee equal to 0.125% per annum is payable in quarterly installments. The interest rate and facility fee are subject to adjustment in the event of a change in the Company’s unsecured debt ratings. The Unsecured Line of Credit involves a syndicate of lenders. The Unsecured Line of Credit contains a competitive bid option that allows banks that are part of the lender consortium to bid to make loan advances to the Company at a negotiated LIBOR-based rate. There were no amounts outstanding on the Unsecured Line of Credit at December 31, 2009. The Company had an outstanding balance on the Unsecured Line of Credit of $100.0 million at December 31, 2008. The weighted-average balance outstanding was approximately $45.2 million and $132.8 million during the years ended December 31, 2009 and 2008, respectively. The weighted-average interest rate on amounts outstanding was approximately 0.95% and 3.58% during the year ended December 31, 2009 and 2008, respectively.

The terms of the Unsecured Line of Credit require that the Company maintain a number of customary financial and other covenants on an ongoing basis, including: (1) a leverage ratio not to exceed 60%, however, the leverage ratio may increase to no greater than 65% provided that it is reduced back to 60% within 180 days, (2) a secured debt leverage ratio not to exceed 55%, (3) a fixed charge coverage ratio of at least 1.40, (4) an unsecured debt leverage ratio not to exceed 60%, however, the unsecured debt leverage ratio may increase to no greater than 65% provided that it is reduced back to 60% within 180 days, (5) a minimum net worth requirement, (6) an unsecured debt interest coverage ratio of at least 1.75 and (7) limitations on permitted investments, development, partially owned entities, business outside of commercial real estate and commercial non-office properties. At December 31, 2009 and 2008, the Company was in compliance with each of these financial and other covenant requirements.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Commitments and Contingencies

10.

Commitments and Contingencies

General

In the normal course of business, the Company guarantees its performance of services or indemnifies third parties against its negligence.

The Company has letter of credit and performance obligations of approximately $13.2 million related to lender and development requirements.

Certain of the Company’s joint venture agreements include provisions whereby, at certain specified times, each partner has the right to initiate a purchase or sale of its interest in the joint ventures. Under these provisions, the Company is not compelled to purchase the interest of its outside joint venture partners.

In connection with the Company’s assumption of the General Motors Building’s secured loan by the Company’s unconsolidated joint venture, 767 Venture, LLC, the Company guaranteed the unconsolidated joint venture’s obligation to fund various escrows, including tenant improvements, taxes and insurance in lieu of cash deposits. As of December 31, 2009, the maximum funding obligation under the guarantee was approximately $23.9 million. From time to time, the Company (or the applicable joint venture) has also agreed to guarantee portions of the principal, interest or other amounts in connection with other unconsolidated joint venture borrowings. In addition to the financial guarantees referenced above, the Company has agreed to customary environmental indemnifications and nonrecourse carve-outs (e.g., guarantees against fraud, misrepresentation and bankruptcy) on certain of its unconsolidated joint venture loans.

Concentrations of Credit Risk

Management of the Company performs ongoing credit evaluations of tenants and may require tenants to provide some form of credit support such as corporate guarantees and/or other financial guarantees. Although the Company’s properties are geographically diverse and the tenants operate in a variety of industries, to the extent the Company has a significant concentration of rental revenue from any single tenant, the inability of that tenant to make its lease payments could have an adverse effect on the Company.

Some potential losses are not covered by insurance.

The Company carries insurance coverage on its properties of types and in amounts and with deductibles that it believes are in line with coverage customarily obtained by owners of similar properties. In response to the uncertainty in the insurance market following the terrorist attacks of September 11, 2001, the Federal Terrorism Risk Insurance Act (as amended, “TRIA”) was enacted in November 2002 to require regulated insurers to make available coverage for “certified” acts of terrorism (as defined by the statute). The expiration date of TRIA was extended to December 31, 2014 by the Terrorism Risk Insurance Program Reauthorization Act of 2007 (“TRIPRA”). Currently, the Company’s property insurance program per occurrence limits are $1.0 billion for its portfolio insurance program, including coverage for acts of terrorism certified under TRIA. The Company currently insures certain properties, including the General Motors Building located at 767 Fifth Avenue in New York, New York (“767 Fifth Avenue”), in separate stand alone insurance programs. The property insurance program per occurrence limits for 767 Fifth Avenue are $1.625 billion, including coverage for acts of terrorism certified under TRIA, with $1.375 billion of coverage for losses in excess of $250 million being provided by NYXP, LLC, as a direct insurer. The Company also currently carries nuclear, biological, chemical and radiological terrorism insurance coverage (“NBCR Coverage”) for acts of terrorism certified under TRIA, which is provided by IXP, LLC as a direct insurer, for the properties in our portfolio, including 767 Fifth Avenue, but excluding the properties owned by the Company’s Value-Added Fund and certain other properties owned in joint ventures with third parties or which we manage. The per occurrence limit for NBCR Coverage is $1.0 billion. Under TRIA, after the payment of the required deductible and coinsurance, the NBCR Coverage is backstopped by the Federal Government if the aggregate industry insured losses resulting from a certified act of terrorism exceed a “program trigger.” The program trigger is $100 million and the coinsurance is 15%. Under TRIPRA, if the Federal Government pays out for a loss under TRIA, it is mandatory that the Federal Government recoup the full amount of the loss from insurers offering TRIA coverage after the payment of the loss pursuant to a formula in TRIPRA. The Company may elect to terminate the NBCR Coverage if the Federal Government seeks recoupment for losses paid under TRIA, if there is a change in its portfolio or for any other reason. The Company intends to continue to monitor the scope, nature and cost of available terrorism insurance and maintain insurance in amounts and on terms that are commercially reasonable.

The Company also currently carries earthquake insurance on its properties located in areas known to be subject to earthquakes in an amount and subject to self-insurance that the Company believes are commercially reasonable. In addition, this insurance is subject to a deductible in the amount of 5% of the value of the affected property. Specifically, the Company currently carries earthquake insurance which covers its San Francisco region with a $120 million per occurrence limit and a $120 million annual aggregate limit, $20 million of which is provided by IXP, LLC, as a direct insurer. The amount of the Company’s earthquake insurance coverage may not be sufficient to cover losses from earthquakes. In addition, the amount of earthquake coverage could impact the Company’s ability to finance properties subject to earthquake risk. The Company may discontinue earthquake insurance on some or all of its properties in the future if the premiums exceed the Company’s estimation of the value of the coverage.

IXP, LLC (“IXP”), a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s earthquake insurance coverage for its Greater San Francisco properties and the Company’s NBCR Coverage for acts of terrorism certified under TRIA. NYXP, LLC (“NYXP”), a captive insurance company which is a wholly-owned subsidiary of the Company, acts as a direct insurer with respect to a portion of the Company’s coverage for acts of terrorism certified under TRIA for 767 Fifth Avenue. Currently, NYXP only insures losses which exceed the program trigger under TRIA and NYXP reinsures with a third-party insurance company any coinsurance payable under TRIA. Insofar as the Company owns IXP and NYXP, it is responsible for their liquidity and capital resources, and the accounts of IXP and NYXP are part of the Company’s consolidated financial statements. In particular, if a loss occurs which is covered by the Company’s NBCR Coverage but is less than the applicable program trigger under TRIA, IXP would be responsible for the full amount of the loss without any backstop by the Federal Government. IXP and NYXP would also be responsible for any recoupment charges by the Federal Government in the event losses are paid out and their insurance policies are maintained after the payout by the Federal Government. If the Company experiences a loss and IXP or NYXP are required to pay under their insurance policies, the Company would ultimately record the loss to the extent of the required payment. Therefore, insurance coverage provided by IXP and NYXP should not be considered as the equivalent of third-party insurance, but rather as a modified form of self-insurance.

The mortgages on the Company’s properties typically contain requirements concerning the financial ratings of the insurers who provide policies covering the property. The Company provides the lenders on a regular basis with the identity of the insurance companies in the Company’s insurance programs. The ratings of some of the Company’s insurers are below the rating requirements in some of the Company’s loan agreements and the lenders for these loans could attempt to claim an event of default has occurred under the loan. The Company believes it could obtain insurance with insurers which satisfy the rating requirements. Additionally, in the future, the Company’s ability to obtain debt financing secured by individual properties, or the terms of such financing, may be adversely affected if lenders generally insist on ratings for insurers which are difficult to obtain or which result in a commercially unreasonable premium. There can be no assurance that a deficiency in the financial ratings of one or more of the Company’s insurers will not have a material adverse effect on the Company.

The Company continues to monitor the state of the insurance market in general, and the scope and costs of coverage for acts of terrorism and California earthquake risk in particular, but the Company cannot anticipate what coverage will be available on commercially reasonable terms in future policy years. There are other types of losses, such as from wars or the presence of mold at the Company’s properties, for which the Company cannot obtain insurance at all or at a reasonable cost. With respect to such losses and losses from acts of terrorism, earthquakes or other catastrophic events, if the Company experiences a loss that is uninsured or that exceeds policy limits, the Company could lose the capital invested in the damaged properties, as well as the anticipated future revenues from those properties. Depending on the specific circumstances of each affected property, it is possible that the Company could be liable for mortgage indebtedness or other obligations related to the property. Any such loss could materially and adversely affect the Company’s business and financial condition and results of operations.

Legal Matters

The Company is subject to various legal proceedings and claims that arise in the ordinary course of business. These matters are generally covered by insurance. Management believes that the final outcome of such matters will not have a material adverse effect on the financial position, results of operations or liquidity of the Company.

State and Local Tax Matters

Because the Company is organized as a limited partnership, it is generally not subject to federal income taxes, but is subject to certain state and local taxes. In the normal course of business, certain entities through which the Company owns real estate either have undergone, or are currently undergoing, tax audits. Although the Company believes that it has substantial arguments in favor of its positions in the ongoing audits, in some instances there is no controlling precedent or interpretive guidance on the specific point at issue. Collectively, tax deficiency notices received to date from the jurisdictions conducting the ongoing audits have not been material. However, there can be no assurance that future audits will not occur with increased frequency or that the ultimate result of such audits will not have a material adverse effect on the Company’s results of operations.

Environmental Matters

It is the Company’s policy to retain independent environmental consultants to conduct or update Phase I environmental assessments (which generally do not involve invasive techniques such as soil or ground water sampling) and asbestos surveys in connection with the Company’s acquisition of properties. These pre-purchase environmental assessments have not revealed environmental conditions that the Company believes will have a material adverse effect on its business, assets, financial condition, results of operations or liquidity, and the Company is not otherwise aware of environmental conditions with respect to its properties that the Company believes would have such a material adverse effect. However, from time to time environmental conditions at the Company’s properties have required and may in the future require environmental testing and/or regulatory filings, as well as remedial action.

In February 1999, the Company (through a joint venture) acquired from Exxon Corporation a property in Massachusetts that was formerly used as a petroleum bulk storage and distribution facility and was known by the state regulatory authority to contain soil and groundwater contamination. The Company developed an office park on the property. The Company engaged a specially licensed environmental consultant to oversee the management of contaminated soil and groundwater that was disturbed in the course of construction. Under the property acquisition agreement, Exxon agreed to (1) bear the liability arising from releases or discharges of oil and hazardous substances which occurred at the site prior to the Company’s ownership, (2) continue monitoring and/or remediating such releases and discharges as necessary and appropriate to comply with applicable requirements, and (3) indemnify the Company for certain losses arising from preexisting site conditions. Any indemnity claim may be subject to various defenses, and there can be no assurance that the amounts paid under the indemnity, if any, would be sufficient to cover the liabilities arising from any such releases and discharges.

Environmental investigations at some of the Company’s properties and certain properties owned by affiliates of the Company have identified groundwater contamination migrating from off-site source properties. In each case the Company engaged a licensed environmental consultant to perform the necessary investigations and assessments and to prepare any required submittals to the regulatory authorities. In each case the environmental consultant concluded that the properties qualify under the regulatory program or the regulatory practice for a status which eliminates certain deadlines for conducting response actions at a site. The Company also believes that these properties qualify for liability relief under certain statutory provisions or regulatory practices regarding upgradient releases. Although the Company believes that the current or former owners of the upgradient source properties may bear responsibility for some or all of the costs of addressing the identified groundwater contamination, the Company will take such further response actions (if any) that it deems necessary or advisable. Other than periodic testing at some of these properties, no such additional response actions are anticipated at this time.

Some of the Company’s properties and certain properties owned by the Company’s affiliates are located in urban, industrial and other previously developed areas where fill or current or historical uses of the areas have caused site contamination. Accordingly, it is sometimes necessary to institute special soil and/or groundwater handling procedures and/or include particular building design features in connection with development, construction and other property operations in order to achieve regulatory closure and/or ensure that contaminated materials are addressed in an appropriate manner. In these situations it is the Company’s practice to investigate the nature and extent of detected contamination and estimate the costs of required response actions and special handling procedures. The Company then uses this information as part of its decision-making process with respect to the acquisition and/or development of the property. For example, the Company owns a parcel in Massachusetts which was formerly used as a quarry/asphalt batching facility. Pre-purchase testing indicated that the site contained relatively low levels of certain contaminants. The Company has engaged a specially licensed environmental consultant to monitor environmental conditions at the site and prepare necessary regulatory submittals based on the results of an environmental risk characterization. A submittal has been made to the regulatory authorities in order to achieve regulatory closure at this site. The submittal included an environmental deed restriction that mandates compliance with certain protective measures in a portion of the site where low levels of residual soil contamination have been left in place in accordance with applicable laws. Development activities on the site are nearing completion and this work will be performed in accordance with the environmental deed restriction and other environmental requirements applicable to the site.

The Company expects that resolution of the environmental matters relating to the above will not have a material impact on its business, assets, financial condition, results of operations or liquidity. However, the Company cannot assure you that it has identified all environmental liabilities at its properties, that all necessary remediation actions have been or will be undertaken at the Company’s properties or that the Company will be indemnified, in full or at all, in the event that such environmental liabilities arise.

Tax Protection Obligations

In connection with the acquisition or contribution of five properties, the Company entered into agreements for the benefit of the selling or contributing parties which specifically state that until such time as the contributors do not hold at least a specified percentage of the OP Units owned by such person following the contribution of the properties, or until June 2017 for one of the properties, the Company will not sell or otherwise transfer the properties in a taxable transaction. If the Company does sell or transfer the properties in a taxable transaction, it would be liable to the contributors for contractual damages.

Noncontrolling Interests

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Noncontrolling Interests

11.

Noncontrolling Interests

Effective January 1, 2009, the Company adopted the guidance included in ASC 810 “Consolidation” (“ASC 810”) (formerly known as SFAS No. 160, “Noncontrolling Interests in Consolidated Financial Statements—an amendment of ARB No. 51” (“SFAS No. 160”)) and ASC 480-10-S99 “Distinguishing Liabilities from Equity” (“ASC 480-10-S99”) (formerly known as EITF Topic No. D-98 “Classification and Measurement of Redeemable Securities” (Amended)), under which noncontrolling interests of the Company (previously known as “minority interests”) are classified either as a component of equity or in the mezzanine section of the balance sheet as temporary equity depending on the terms of such noncontrolling interests. As a result of the adoption of the guidance included in ASC 810, the Company reclassified the noncontrolling interests in consolidated property partnerships from the mezzanine section of its Consolidated Balance Sheets to capital. The reclassification totaled approximately $6.9 million as of December 31, 2008. Noncontrolling interests related to redeemable preferred units and redeemable common units of the Company continue to be classified in the mezzanine section of the Consolidated Balance Sheets. Noncontrolling interests related to redeemable common units of the Company are adjusted each period to reflect the carrying value equal to the greater of the carrying value based on historical cost or the redemption value.

Under the guidance included in ASC 810, net income encompasses the total income of all consolidated subsidiaries and there is a separate disclosure of the attribution of that income between controlling and noncontrolling interests. The implementation of this standard had no effect on the Company’s results of operations. As a result of the adoption of the guidance included in ASC 810, net income attributable to noncontrolling interests is now deducted from net income in the determination of net income attributable to the Company for all periods presented. In addition, other comprehensive income (loss) attributable to noncontrolling interests is now deducted from comprehensive income in the determination of comprehensive income attributable to the Company for all periods presented.

Noncontrolling interests relate to the interests in the Company not owned by Boston Properties, Inc. and interests in property partnerships not wholly-owned by the Company. As of December 31, 2009, the noncontrolling interests consisted of 19,814,499 OP Units, 1,416,162 LTIP Units, 1,080,938 2008 OPP Units and 1,113,044 Series Two Preferred Units (or 1,460,688 OP Units on an as converted basis) held by parties other than Boston Properties, Inc.

Noncontrolling Interest—Redeemable Preferred Units

The Preferred Units at December 31, 2009 and 2008 consisted solely of 1,113,044 Series Two Preferred Units, which bear a preferred distribution equal to the greater of (1) the distribution which would have been paid in respect of the Series Two Preferred Unit had such Series Two Preferred Unit been converted into an OP Unit (including both regular and special distributions) or (2) a rate ranging from 5.00% to 7.00% per annum on a liquidation preference of $50.00 per unit, and are convertible into OP Units at a rate of $38.10 per Preferred Unit (1.312336 OP Units for each Preferred Unit). Distributions on the Series Two Preferred Units are payable quarterly and, unless the greater rate described in the next sentence applies, accrue at 7.0% until May 12, 2009 and 6.0% thereafter. If distributions on the number of OP Units into which the Series Two Preferred Units are convertible are greater than distributions calculated using the rates described in the preceding sentence for the applicable quarterly period, then the greater distributions are payable instead. The holders of Series Two Preferred Units have the right to require the Company to redeem their units for cash at the redemption price of $50.00 per unit on May 12, 2010, May 12, 2011, May 14, 2012, May 14, 2013 and May 12, 2014. The maximum number of units that may be required to be redeemed from all holders on each of these dates is 1,007,662, which is one-sixth of the number of Series Two Preferred Units that were originally issued. The holders had the right to have their Series Two Preferred Units redeemed for cash on May 12, 2009, although no holder exercised such right. The Company also has the right, under certain conditions and at certain times, to redeem Series Two Preferred Units for cash and to convert into OP Units any Series Two Preferred Units that are not redeemed when they are eligible for redemption.

On February 17, 2009, the Company paid a distribution on its outstanding Series Two Preferred Units of $0.89239 per unit. On May 15, 2009, the Company paid a distribution on its outstanding Series Two Preferred Units of $0.89239 per unit. On August 17, 2009, the Company paid a distribution on its outstanding Series Two Preferred Units of $0.75616 per unit. On November 16, 2009, the Company paid a distribution on its outstanding Series Two Preferred Units of $0.75616 per unit.

Due to the redemption option and the conversion option existing outside the control of the Company, such Preferred Units are not included in Partners’ Capital and are reflected in the Consolidated Balance Sheets at an amount equivalent to the value of such units had such units been redeemed at December 31, 2009. The value of the Series Two Preferred Units had all of such units been converted and then redeemed at December 31, 2009 was approximately $98.0 million based on the closing price of Boston Properties, Inc.’s common stock of $67.07 per share.

The following table reflects the activity for noncontrolling interests—redeemable preferred units for the years ended December 31, 2009, 2008 and 2007:


Balance at December 31, 2006	$	252,424
Net income		10,429
Distributions		(9,870	)
Reallocation of partnership interest (1)		(118,877	)

Balance at December 31, 2007		134,106
Net income		4,226
Distributions		(3,738	)
Reallocation of partnership interest		(54,256	)

Balance at December 31, 2008		80,338
Net income		3,594
Distributions		(3,594	)
Reallocation of partnership interest		17,630

Balance at December 31, 2009	$	97,968

(1)	Includes the conversion of 606,186 Series Two Preferred Units into 795,520 OP Units during the year ended December 31, 2007.

Noncontrolling Interest—Common Units

During the years ended December 31, 2009 and 2008, 138,856 and 631,297 OP Units, respectively, were presented by the holders for redemption and were redeemed by Boston Properties, Inc. in exchange for an equal number of shares of Common Stock.

At December 31, 2009, the Company had outstanding 1,080,938 2008 OPP Units. Prior to the measurement date on February 5, 2011, 2008 OPP Units will be entitled to receive per unit distributions equal to one-tenth (10%) of the regular quarterly distributions payable on an OP Unit, but will not be entitled to receive any special distributions. After the measurement date, the number of 2008 OPP Units, both vested and unvested, which 2008 OPP award recipients have earned, if any, based on the establishment of an outperformance pool, will be entitled to receive distributions in an amount per unit equal to distributions, both regular and special, payable on an OP Unit.

On January 30, 2009, the Company paid a distribution on the OP Units and LTIP Units in the amount of $0.68 per unit and a distribution on the 2008 OPP Units in the amount of $0.068 per unit to holders of record as of the close of business on December 31, 2008. On April 30, 2009, the Company paid a distribution on the OP Units and LTIP Units in the amount of $0.68 per unit and a distribution on the 2008 OPP Units in the amount of $0.068 per unit to holders of record as of the close of business on March 31, 2009. On July 31, 2009, the Company paid a distribution on the OP Units and LTIP Units in the amount of $0.50 per unit and a distribution on the 2008 OPP Units in the amount of $0.05 per unit to holders of record as of the close of business on June 30, 2009. On October 30, 2009, the Company paid a distribution on the OP Units and LTIP Units in the amount of $0.50 per unit and a distribution on the 2008 OPP Units in the amount of $0.05 per unit to holders of record as of the close of business on September 30, 2009. On December 17, 2009, Boston Properties, Inc., as general partner of the Company, declared a distribution on the OP Units and LTIP Units in the amount of $0.50 per unit and a distribution on the 2008 OPP Units in the amount of $0.05 per unit, in each case payable on January 29, 2010 to holders of record as of the close of business on December 31, 2009.

Pursuant to the Company’s Partnership Agreement, certain limited partners in the Company have the right to redeem all or any portion of their interest for cash from the Company. However, Boston Properties, Inc. may elect to acquire the interest by issuing its Common Stock in exchange for their interest. The amount of cash to be paid to the limited partner if the redemption right is exercised and the cash option is elected is based on the trading price of Boston Properties, Inc.’s common stock at that time. Due to the redemption option existing outside the control of the Company, such limited partners’ units are not included in Partners’ Capital. The value of the OP Units not owned by Boston Properties, Inc. (including LTIP Units assuming that all conditions have been met for the conversion thereof) had all of such units been redeemed at December 31, 2009 was approximately $1.42 billion based on the closing price of Boston Properties, Inc.’s common stock of $67.07 per share.

The following table reflects the activity for noncontrolling interests—redeemable common units for the years ended December 31, 2009, 2008 and 2007:


Balance at December 31, 2006	$	2,387,374
Contributions		17,148
Net income		232,808
Distributions		(182,294	)
Conversion of redeemable partnership units		(30,590	)
Unearned compensation		(7,216	)
Accumulated other comprehensive loss		(3,798	)
Adjustments to reflect redeemable partnership units at redemption value		(490,251	)

Balance at December 31, 2007		1,923,181
Contributions		68,209
Net income		19,223
Distributions		(57,608	)
Conversion of redeemable partnership units		(10,906	)
Unearned compensation		(21,578	)
Accumulated other comprehensive loss		(105	)
Adjustments to reflect redeemable partnership units at redemption value		(773,359	)

Balance at December 31, 2008		1,147,057
Contributions		20,474
Net income		37,122
Distributions		(46,574	)
Conversion of redeemable partnership units		(3,970	)
Unearned compensation		4,250
Accumulated other comprehensive loss		390
Adjustments to reflect redeemable partnership units at redemption value		272,917

Balance at December 31, 2009	$	1,431,666

Noncontrolling Interest—Property Partnerships

The noncontrolling interests in property partnerships consist of the outside equity interests in joint ventures that are consolidated with the financial results of the Company because the Company exercises control over the entities that own the properties. The equity interests in these ventures that are not owned by the Company, totaling approximately $5.7 million and $6.9 million at December 31, 2009 and December 31, 2008, respectively, are included in Noncontrolling Interests in Property Partnerships on the accompanying Consolidated Balance Sheets.

The following table reflects the activity for noncontrolling interests in property partnerships units for the years ended December 31, 2009, 2008 and 2007:


Balance at December 31, 2006	$	12,454
Contributions		4,311
Net income		84
Distributions		(10,632	)
Consolidation of noncontrolling interest in property partnership		19,588

Balance at December 31, 2007		25,805
Net income		1,997
Distributions		(20,902	)

Balance at December 31, 2008		6,900
Net income		2,778
Distributions		(4,007	)

Balance at December 31, 2009	$	5,671

On January 5, 2009, the Company repaid a $25.0 million loan in connection with the agreement entered into in May 2006 to redeem the outside members’ equity interests in the limited liability company that owns 601 Lexington Avenue (formerly known as Citigroup Center).

Partners' Capital

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Partners' Capital

12.

Partners’ Capital

The following table presents the changes in the issued and outstanding partners’ capital units since January 1, 2007:


	General Partner Units	Limited Partner Units	Total Partners’ Capital Units
Outstanding at January 1, 2007	1,388,422	116,115,120	117,503,542
Units issued to Boston Properties, Inc. related to Common Stock issued for the conversion of Preferred Units	6,392	788,376	794,768
Units issued to Boston Properties, Inc. related to Common Stock issued under the Employee Stock Purchase Plan	50	6,116	6,166
Units issued to Boston Properties, Inc. related to Common Stock issued under the Stock Option and Incentive Plan	5,232	645,319	650,551
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	4,403	543,055	547,458

Outstanding at December 31, 2007	1,404,499	118,097,986	119,502,485
Units issued to Boston Properties, Inc. related to Common Stock issued under the Employee Stock Purchase Plan	73	7,682	7,755
Units issued to Boston Properties, Inc. related to Common Stock issued under the Stock Option and Incentive Plan	9,823	1,029,295	1,039,118
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	5,967	625,330	631,297

Outstanding at December 31, 2008	1,420,362	119,760,293	121,180,655
Units issued to Boston Properties, Inc. related to Common Stock issued under the Employee Stock Purchase Plan	124	11,981	12,105
Units issued to Boston Properties, Inc. related to Common Stock issued under the Stock Option and Incentive Plan, net	3,047	295,347	298,394
Units issued to Boston Properties, Inc. related to Common Stock issued in exchange for OP Units	1,418	137,438	138,856
Units issued to Boston Properties, Inc. related to Common Stock issued for the completion of a public offering	176,156	17,073,844	17,250,000

Outstanding at December 31, 2009	1,601,107	137,278,903	138,880,010

As of December 31, 2009, Boston Properties, Inc. owned 1,601,107 general partnership units and 137,278,903 limited partnership units.

On June 10, 2009, Boston Properties, Inc. completed a public offering of 17,250,000 shares of its Common Stock (including 2,250,000 shares issued as a result of the exercise of an overallotment option by the underwriters) at a price to the public of $50.00 per share. The proceeds from this public offering, net of underwriters’ discounts and offering costs, totaled approximately $841.9 million, which was contributed by Boston Properties, Inc. to the Company in exchange for 17,250,000 OP Units.

During the years ended December 31, 2009 and 2008, the Company issued 242,507 and 1,058,133 OP Units, respectively, to Boston Properties, Inc. in connection with the exercise by employees of options to purchase Common Stock of Boston Properties, Inc.

During the years ended December 31, 2009 and 2008, Boston Properties, Inc. acquired 138,856 and 631,297 OP Units, respectively, in connection with the redemption of an equal number of redeemable OP Units from third parties.

On January 30, 2009, the Company paid a distribution in the amount of $0.68 per OP Unit to unitholders of record as of the close of business on December 31, 2008. On April 30, 2009, the Company paid a distribution in the amount of $0.68 per OP Unit to unitholders of record as of the close of business on March 31, 2009. On July 31, 2009, the Company paid a distribution in the amount of $0.50 per OP Unit to unitholders of record as of the close of business on June 30, 2009. On October 30, 2009, the Company paid a distribution in the amount of $0.50 per OP Unit to unitholders of record as of the close of business on September 30, 2009. On December 17, 2009, Boston Properties, Inc., as general partner of the Company, declared a distribution in the amount of $0.50 per OP Unit payable on January 29, 2010 to unitholders of record as of the close of business on December 31, 2009.

Future Minimum Rents

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Future Minimum Rents

13.

Future Minimum Rents

The properties are leased to tenants under net operating leases with initial term expiration dates ranging from 2010 to 2049. The future contractual minimum lease payments to be received (excluding operating expense reimbursements) by the Company as of December 31, 2009, under non-cancelable operating leases which expire on various dates through 2049, are as follows:


Years Ending December 31,	(in thousands)
2010	$	1,114,614
2011		1,115,809
2012		1,047,167
2013		981,599
2014		918,525
Thereafter		4,627,558

No single tenant represented more than 10.0% of the Company’s total rental revenue for the years ended December 31, 2009, 2008 and 2007.

Segment Reporting

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Segment Reporting

14.

Segment Reporting

The Company’s segments are based on the Company’s method of internal reporting which classifies its operations by both geographic area and property type. The Company’s segments by geographic area are Greater Boston, Greater Washington, DC, Midtown Manhattan, Greater San Francisco and New Jersey. Segments by property type include: Class A Office, Office/Technical and Hotels.

Asset information by segment is not reported because the Company does not use this measure to assess performance. Therefore, depreciation and amortization expense is not allocated among segments. Interest and other income, development and management services, general and administrative expenses, interest expense, depreciation and amortization expense, loss from suspension of development, net derivative losses, losses (gains) from investments in securities, losses from early extinguishments of debt, income (loss) from unconsolidated joint ventures, gains on sales of real estate and other assets, income from discontinued operations, gains on sales of real estate from discontinued operations and noncontrolling interests are not included in Net Operating Income as internal reporting addresses these items on a corporate level.

Net Operating Income is not a measure of operating results or cash flows from operating activities as measured by accounting principles generally accepted in the United States of America, and it is not indicative of cash available to fund cash needs and should not be considered an alternative to cash flows as a measure of liquidity. All companies may not calculate Net Operating Income in the same manner. The Company considers Net Operating Income to be an appropriate supplemental measure to net income because it helps both investors and management to understand the core operations of the Company’s properties.

Information by geographic area and property type (dollars in thousands):

For the year ended December 31, 2009:


	Greater Boston			Greater Washington, DC			Midtown Manhattan			Greater San Francisco			New Jersey			Total
Rental Revenue:
Class A Office	$	364,064		$	318,786		$	441,571		$	218,432		$	63,189		$	1,406,042
Office/Technical		30,655			16,230			—			—			—			46,885
Hotels		30,385			—			—			—			—			30,385

Total		425,104			335,016			441,571			218,432			63,189			1,483,312
% of Grand Totals		28.66	%		22.58	%		29.77	%		14.73	%		4.26	%		100.0	%
Rental Expenses:
Class A Office		137,785			93,799			146,398			80,269			29,751			488,002
Office/Technical		9,475			4,322			—			—			—			13,797
Hotels		23,966			—			—			—			—			23,966

Total		171,226			98,121			146.398			80,269			29,751			525,765
% of Grand Totals		32.57	%		18.66	%		27.84	%		15.27	%		5.66	%		100.0	%

Net operating income	$	253,878		$	236,895		$	295,173		$	138,163		$	33,438		$	957,547

% of Grand Totals		26.51	%		24.74	%		30.83	%		14.43	%		3.49	%		100.0	%

For the year ended December 31, 2008:


	Greater Boston			Greater Washington, DC			Midtown Manhattan			Greater San Francisco			New Jersey			Total
Rental Revenue:
Class A Office	$	360,468		$	282,166		$	435,219		$	214,202		$	63,908		$	1,355,963
Office/Technical		30,634			15,455			—			—			—			46,089
Hotels		36,872			—			—			—			—			36,872

Total		427,974			297,621			435,219			214,202			63,908			1,438,924
% of Grand Totals		29.74	%		20.68	%		30.25	%		14.89	%		4.44	%		100.0	%
Rental Expenses:
Class A Office		139,448			82,227			142,764			79,553			30,705			474,697
Office/Technical		9,650			3,683			—			—			—			13,333
Hotels		27,510			—			—			—			—			27,510

Total		176,608			85,910			142,764			79,553			30,705			515,540
% of Grand Totals		34.26	%		16.66	%		27.69	%		15.43	%		5.96	%		100.0	%

Net operating income	$	251,366		$	211,711		$	292,455		$	134,649		$	33,203		$	923,384

% of Grand Totals		27.22	%		22.93	%		31.67	%		14.58	%		3.60	%		100.0	%

For the year ended December 31, 2007:


	Greater Boston			Greater Washington, DC			Midtown Manhattan			Greater San Francisco			New Jersey			Total
Rental Revenue:
Class A Office	$	336,974		$	240,413		$	443,382		$	203,450		$	67,582		$	1,291,801
Office/Technical		28,085			14,333			—			—			—			42,418
Hotels		37,811			—			—			—			—			37,811

Total		402,870			254,746			443,382			203,450			67,582			1,372,030
% of Grand Totals		29.35	%		18.57	%		32.32	%		14.83	%		4.93	%		100.0	%
Rental Expenses:
Class A Office		129,643			68,749			137,404			78,597			29,422			443,815
Office/Technical		8,831			3,194			—			—			—			12,025
Hotels		27,765			—			—			—			—			27,765

Total		166,239			71,943			137,404			78,597			29,422			483,605
% of Grand Totals		34.38	%		14.88	%		28.41	%		16.25	%		6.08	%		100.0	%

Net operating income	$	236,631		$	182,803		$	305,978		$	124,853		$	38,160		$	888,425

% of Grand Totals		26.63	%		20.58	%		34.44	%		14.05	%		4.30	%		100.0	%

The following is a reconciliation of Net Operating Income to net attributable to Boston Properties Limited Partnership (in thousands):


	Years ended December 31,
	2009			2008			2007
Net operating income	$	957,547		$	923,384		$	888,425
Add:
Development and management services		34,878			30,518			20,553
Interest and other		4,059			18,958			89,706
Income (loss) from unconsolidated joint ventures		12,058			(182,018	)		20,428
Gains on sales of real estate and other assets		11,760			33,340			957,406
Gains on sales of real estate from discontinued operations		—			—			266,817
Income from discontinued operations		—			—			7,274

Less:
General and administrative		75,447			72,365			69,882
Interest expense		322,833			295,322			302,980
Depreciation and amortization		313,458			296,122			278,249
Loss from suspension of development		27,766			—			—
Net derivative losses		—			17,021			—
Losses (gains) from investments in securities		(2,434	)		4,604			—
Losses from early extinguishments of debt		510			—			3,417
Noncontrolling interests in property partnerships		2,778			1,997			84
Noncontrolling interest—redeemable preferred units		3,594			4,226			10,429

Net income attributable to Boston Properties Limited Partnership	$	276,350		$	132,525		$	1,585,568

Earnings Per Common Unit

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Earnings Per Common Unit

15.

Earnings Per Common Unit

Earnings per common unit has been computed pursuant to the provisions of ASC 260-10 “Earnings Per Share” (“ASC 260-10”). During 2004, the Company adopted the guidance included in ASC 260-10 (formerly known as EITF 03-6 “Participating Securities and the Two-Class Method under FASB 128” (“EITF 03-6”)), which provides further guidance on the definition of participating securities. Pursuant to the guidance included in ASC 260-10, the Company’s Series Two Preferred Units, which are reflected as Noncontrolling Interests—Redeemable Partnership Units in the Company’s Consolidated Balance Sheets, are considered participating securities and are included in the computation of basic and diluted earnings per common unit of the Company if the effect of applying the if-converted method is dilutive. The terms of the Series Two Preferred Units enable the holders to obtain OP Units of the Company. In June 2008, the FASB issued guidance included in ASC 260-10 (formerly known as FSP EITF 03-6-1, “Determining Whether Instruments Granted in Share-Based Payment Transactions are Participating Securities” (“FSP EITF 03-6-1”)). The guidance included in ASC 260-10 clarifies that unvested share-based payment awards that contain non-forfeitable rights to dividends or dividend equivalents (whether paid or unpaid) are participating securities and shall be included in the computation of earnings per common unit pursuant to the two-class method. The guidance included in ASC 260-10 requires the retrospective adjustment of all prior-period earnings per common unit data presented (including interim financial statements, summaries of earnings, and selected financial data) to conform with the provisions of the guidance. Early application was not permitted. As a result, the Company’s unvested restricted stock, LTIP Units and 2008 OPP Units are considered participating securities and are included in the computation of basic and diluted earnings per common unit of the Company if the effect of applying the if-converted method is dilutive. The adoption of the guidance included in ASC 260-10 on January 1, 2009 did not have a material impact on the Company’s computation of earnings per common unit. Because the 2008 OPP Units require Boston Properties, Inc. to outperform absolute and relative return thresholds, unless such thresholds have been met by the end of the applicable reporting period, the Company excludes all the 2008 OPP Units from the diluted earnings per common unit calculation. For the years ended December 31, 2009 and 2008, the absolute and relative return thresholds for the 2008 OPP Units were not met and as a result the 2008 OPP Units have been excluded from the diluted earnings per common unit calculation. Other potentially dilutive common units and the related impact on earnings are considered when calculating diluted earnings per common unit. Included in the number of units (the denominator) below are approximately 20,336,000, 20,356,000 and 20,451,000 redeemable common units for the years ended December 31, 2009, 2008 and 2007, respectively. The following table provides a reconciliation of both the net income attributable to Boston Properties Limited Partnership and the number of common units used in the computation of basic earnings per common unit, which is calculated by dividing net income attributable to Boston Properties Limited Partnership by the weighted-average number of common units outstanding during the period.


	For the year ended December 31, 2009
	Income (Numerator)			Units (Denominator)		Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership	$	276,350		151,386		$	1.83
Effect of Dilutive Securities:
Stock Based Compensation		—		462			(0.01	)
Diluted Earnings:

Net income	$	276,350		151,848		$	1.82

	For the year ended December 31, 2008
	Income (Numerator)				Units (Denominator)		Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Net income attributable to Boston Properties Limited Partnership	$	132,525			140,336		$	0.94
Effect of Dilutive Securities:
Stock Based Compensation		—			1,319			(0.00	)
Diluted Earnings:

Net income	$	132,525			141,655		$	0.94


	For the year ended December 31, 2007
	Income (Numerator)				Units (Denominator)		Per Unit Amount
	(in thousands, except for per unit amounts)
Basic Earnings:
Income attributable to Boston Properties Limited Partnership before discontinued operations and allocation of undistributed earnings to participating securities	$	1,311,477			139,290		$	9.41
Discontinued operations		274,091			—			1.97
Allocation of undistributed earnings to participating securities		(6,118	)		—			(0.04	)

Net income attributable to Boston Properties Limited Partnership		1,579,450			139,290			11.34
Effect of Dilutive Securities:
Stock Based Compensation		—			1,763			(0.15	)
Exchangeable Senior Notes		—			178			(0.01	)
Diluted Earnings:

Net income	$	1,579,450			141,231		$	11.18

Employee Benefit Plans

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Employee Benefit Plans

16.

Employee Benefit Plans

Effective January 1, 1985, the predecessor of the Company adopted a 401(k) Savings Plan (the “Plan”) for its employees. Under the Plan, as amended, employees, as defined, are eligible to participate in the Plan after they have completed three months of service. Upon formation, the Company adopted the Plan and the terms of the Plan.

Effective January 1, 2000, the Company amended the Plan by increasing the Company’s matching contribution to 200% of the first 3% from 200% of the first 2% of participant’s eligible earnings contributed (utilizing earnings that are not in excess of an amount established by the IRS ($245,000, $230,000 and $225,000 in 2009, 2008 and 2007, respectively), indexed for inflation) and by eliminating the vesting requirement. The Company’s aggregate matching contribution for the years ended December 31, 2009, 2008 and 2007 was $3.0 million, $2.7 million and $2.1 million, respectively.

Effective January 1, 2001, the Company amended the Plan to provide a supplemental retirement contribution to employees who have at least ten years of service on January 1, 2001, and who are 40 years of age or older as of January 1, 2001. The maximum supplemental retirement contribution will not exceed the annual limit on contributions established by the Internal Revenue Service. The Company will record an annual supplemental retirement credit for the benefit of each participant. The Company’s supplemental retirement contribution and credit for the years ended December 31, 2009, 2008 and 2007 was $122,000, $210,000 and $178,000, respectively.

The Company also maintains a deferred compensation plan that is designed to allow officers of the Company to defer a portion of their current income on a pre-tax basis and receive a tax-deferred return on these deferrals. The Company’s obligation under the plan is that of an unsecured promise to pay the deferred compensation to the plan participants in the future. At December 31, 2009 and 2008, the Company has funded approximately $9.9 million and $6.6 million, respectively, into a separate account, which is not restricted as to its use. The Company’s liability under the plan is equal to the total amount of compensation deferred by the plan participants and earnings on the deferred compensation pursuant to investments elected by the plan participants. The Company’s liability as of December 31, 2009 and 2008 was $9.8 million and $6.3 million, respectively, which are included in the accompanying Consolidated Balance Sheets.

Stock Option and Incentive Plan and Stock Purchase Plan

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Stock Option and Incentive Plan and Stock Purchase Plan

17.

Stock Option and Incentive Plan and Stock Purchase Plan

Boston Properties, Inc. has established a stock option and incentive plan for the purpose of attracting and retaining qualified employees and rewarding them for superior performance in achieving the Company’s business goals and enhancing stockholder value.

At Boston Properties, Inc.’s 2007 annual meeting of stockholders held on May 15, 2007, Boston Properties, Inc.’s stockholders approved an amendment and restatement of Boston Properties, Inc.’s 1997 Stock Option and Incentive Plan (the “1997 Plan”) that, among other things, (1) increased the limit on full value shares (i.e., awards other than stock options) that may be issued under the Plan by 2,500,000 shares, (2) extended the term of the Plan to May 15, 2017 and (3) added provisions that allow Boston Properties, Inc. to qualify certain grants under the Plan as “performance-based compensation” under Section 162(m) of the Internal Revenue Code.

Under the amended plan, the number of shares of Common Stock of Boston Properties, Inc. available for issuance is 4,019,174 shares. At December 31, 2009, the number of shares available for issuance under the plan was 1,901,049, of which a maximum of 1,447,508 shares may be granted as awards other than stock options.

Options granted under the plan became exercisable over a two-, three- or five-year period and have terms of ten years, as determined at the time of the grant. All options were granted at the fair market value of Boston Properties, Inc.’s Common Stock at the dates of grant. As of January 17, 2005, all outstanding options had become fully vested and exercisable.

On January 24, 2008, the Compensation Committee (the “Committee”) of the Board of Directors (the “Board”) of Boston Properties, Inc. approved outperformance awards under the 1997 Plan to officers and key employees of Boston Properties, Inc. These awards (the “2008 OPP Awards”) are part of a broad-based, long-term incentive compensation program designed to provide the Company’s management team at several levels within the organization with the potential to earn equity awards subject to Boston Properties, Inc. “outperforming” and creating shareholder value in a pay-for-performance structure. 2008 OPP Awards utilize total return to shareholders (“TRS”) over a three-year measurement period as the performance metric and include two years of time-based vesting after the end of the performance measurement period (subject to acceleration in certain events) as a retention tool. Recipients of 2008 OPP Awards will share in an outperformance pool if Boston Properties, Inc.’s TRS, including both share appreciation and dividends, exceeds absolute and relative hurdles over a three-year measurement period from February 5, 2008 to February 5, 2011, based on the average closing price of a share of Boston Properties, Inc.’s common stock (a “REIT Share”) of $92.8240 for the five trading days prior to and including February 5, 2008. The aggregate reward that recipients of all 2008 OPP Awards can earn, as measured by the outperformance pool, is subject to a maximum cap of $110 million, although only awards for an aggregate of up to approximately $104.8 million have been granted to date. The balance remains available for future grants, with OPP awards exceeding a potential reward of $1 million requiring the Committee’s approval.

The outperformance pool will consist of (i) three percent (3%) of the excess total return above a cumulative absolute TRS hurdle of 30% over the full three-year measurement period (the “Absolute TRS Component”) and (ii) three percent (3%) of the excess or deficient excess total return above or below a relative TRS hurdle equal to the total return of the SNL Equity REIT Index over the three-year measurement period (the “Relative TRS Component”). In the event that the Relative TRS Component is potentially positive because Boston Properties, Inc.’s TRS is higher than the total return of the SNL Equity REIT Index, the actual contribution to the outperformance pool from the Relative TRS Component will be subject to a sliding scale factor as follows: (i) 100% of the potential Relative TRS Component will be earned if Boston Properties, Inc.’s TRS is equal to or greater than a cumulative 30% over three years (equivalent to 10% per annum), (ii) 0% will be earned if Boston Properties, Inc.’s TRS is equal to or less than a cumulative 21% over three years (equivalent to 7% per annum), and (iii) a percentage from 0% to 100% calculated by linear interpolation will be earned if Boston Properties, Inc.’s cumulative TRS over three years is between 21% and 30%. The potential Relative TRS Component before application of the sliding scale factor will be capped at $110 million (or such lesser amount as corresponds to the OPP awards actually granted). In the event that the Relative TRS Component is negative because Boston Properties, Inc.’s TRS is less than the total return of the SNL Equity REIT Index, any outperformance reward potentially earned under the Absolute TRS Component will be reduced dollar for dollar, provided that the potential Absolute TRS Component before reduction for any negative Relative TRS Component will be capped at $110 million (or such lesser amount as corresponds to the OPP awards actually granted). The algebraic sum of the Absolute TRS Component and the Relative TRS Component determined as described above will never exceed $110 million (or such lesser amount as corresponds to the OPP awards actually granted).

Each employee’s 2008 OPP Award is designated as a specified percentage of the aggregate outperformance pool. Assuming the applicable absolute and/or relative TRS thresholds are achieved at the end of the measurement period, the algebraic sum of the Absolute TRS Component and the Relative TRS Component will be calculated and then allocated among the 2008 OPP Award recipients in accordance with each individual’s percentage. Rewards earned with respect to 2008 OPP Awards will vest 25% on February 5, 2011, 25% on February 5, 2012, and 50% on February 5, 2013, based on continued employment. Vesting will be accelerated in the event of a change of control of Boston Properties, Inc., termination of employment by Boston Properties, Inc. without cause or termination of employment by the award recipient for good reason, death, disability or retirement, although restrictions on transfer will continue to apply in certain of these situations. 2008 OPP Awards are in the form of LTIP units of limited partnership interest of the Company, which are referred to herein as “2008 OPP Units.” 2008 OPP Units were issued prior to the determination of the outperformance pool, but will remain subject to forfeiture depending on the extent of rewards earned with respect to 2008 OPP Awards. The number of 2008 OPP Units issued initially to recipients of the 2008 OPP Awards was an estimate of the maximum number of 2008 OPP Units that they could earn, based on certain assumptions. The number of 2008 OPP Units actually earned by each award recipient, if any, will be determined at the end of the performance measurement period by dividing his or her share of the outperformance pool by the average closing price of a share of common stock for the 15 trading days immediately preceding the measurement date. Total return for Boston Properties, Inc. and for the SNL Equity REIT Index over the three-year measurement period and other circumstances will determine how many 2008 OPP Units are earned by each recipient; if they are fewer than the number issued initially, the balance will be forfeited as of the performance measurement date.

Prior to the measurement date, 2008 OPP Units will be entitled to receive per unit distributions equal to one-tenth (10%) of the regular quarterly distributions payable on an OP Unit, but will not be entitled to receive any special distributions. After the measurement date, the number of 2008 OPP Units, both vested and unvested, which employees have earned based on the establishment of an outperformance pool, will be entitled to receive distributions in an amount per unit equal to distributions, both regular and special, payable on an OP Unit.

Boston Properties, Inc. issued 62,876, 4,723 and 6,536 shares of restricted stock and the Company issued 515,007, 288,507 and 156,161 LTIP Units to employees and directors under the 1997 Plan during the years ended December 31, 2009, 2008 and 2007, respectively. The Company issued 1,085,861 2008 OPP Units under the 1997 Plan during the year ended December 31, 2008. Employees paid $0.01 per share of restricted common stock and $0.25 per LTIP and 2008 OPP Unit. An LTIP Unit is generally the economic equivalent of a share of restricted stock in Boston Properties, Inc. The aggregate value of the LTIP Units is included in Noncontrolling Interests – Redeemable Partnership Units in the Consolidated Balance Sheets. The restricted stock and LTIP Units granted to employees between January 1, 2004 and November 2006 vest over a five-year term. Grants of restricted stock and LTIP Units made on and after November 22, 2006 vest in four equal annual installments. Restricted stock and LTIP Units are measured at fair value on the date of grant based on the number of shares or units granted, as adjusted for forfeitures, and the price of Boston Properties, Inc.’s Common Stock on the date of grant as quoted on the New York Stock Exchange. Such value is recognized as an expense ratably over the corresponding employee service period. As the 2008 OPP Awards are subject to both a service condition and a market condition, the Company recognizes the compensation expense related to the 2008 OPP Awards under the graded vesting attribution method. Under the graded vesting attribution method, each portion of the award that vests at a different date is accounted for as a separate award and recognized over the period appropriate to that portion so that the compensation cost for each portion should be recognized in full by the time that portion vests. Dividends paid on both vested and unvested shares of restricted stock are charged directly to Partners’ Capital and Redeemable Partnership Units, respectively, in the Consolidated Balance Sheets. Stock-based compensation expense associated with restricted stock, LTIP Units and 2008 OPP Units was approximately $25.6 million, $22.1 million and $11.4 million for the years ended December 31, 2009, 2008 and 2007, respectively. At December 31, 2009, there was $34.7 million of unrecognized compensation expense related to unvested restricted stock and LTIP Units and $9.0 million of unrecognized compensation expense related to unvested 2008 OPP Units that is expected to be recognized over a weighted-average period of approximately 2.4 years.

The shares of restricted stock were valued at approximately $2.8 million ($43.89 per share weighted-average), $0.5 million ($96.09 per share weighted-average) and $0.8 million ($125.46 per share weighted-average) for the years ended December 31, 2009, 2008 and 2007, respectively.

LTIP Units were valued using a Monte Carlo simulation method model in accordance with the provisions of ASC 718 “Compensation—Stock Compensation” (“ASC 718”) (formerly SFAS No. 123R). LTIP Units issued during the years ended December 31, 2009, 2008 and 2007 were valued at approximately $21.1 million, $25.4 million and $18.0 million, respectively. The weighted-average per unit fair value of LTIP Unit grants in 2009, 2008 and 2007 was $41.05, $88.08 and $115.47, respectively. The per unit fair value of each LTIP Unit granted in 2009, 2008 and 2007 was estimated on the date of grant using the following assumptions; an expected life of 5.6 years, 5.6 years and 5.3 years, a risk-free interest rate of 1.87%, 2.75% and 4.82% and an expected price volatility of 40.0%, 25.0% and 18.0%, respectively.

The 2008 OPP Units were valued at approximately $19.7 million utilizing a Monte Carlo simulation to estimate the probability of the performance vesting conditions being satisfied. The Monte Carlo simulation used a statistical formula underlying the Black-Scholes and binomial formulas and such simulation was run approximately 100,000 times. For each simulation, the payoff is calculated at the settlement date, which is then discounted to the award date at a risk-free interest rate. The average of the values over all simulations is the expected value of the unit on the award date. Assumptions used in the valuations included (1) factors associated with the underlying performance of Boston Properties, Inc.’s stock price and total shareholder return over the term of the performance awards including total stock return volatility and risk-free interest and (2) factors associated with the relative performance of Boston Properties, Inc.’s stock price and total shareholder return when compared to the SNL Equity REIT Index. The valuation was performed in a risk-neutral framework, so no assumption was made with respect to an equity risk premium. The fair value of the 2008 OPP Units is based on the sum of: (1) the present value of the expected payoff to the OPP Award on the measurement date, if the total return to stockholders (“TRS”) over the applicable measurement period exceeds performance hurdles of the Absolute and the Relative Components; and (2) the present value of the distributions payable on the 2008 OPP Units. The ultimate reward realized on account of the OPP Award by the holders of the 2008 OPP Units is contingent on the TRS achieved on the measurement date, both in absolute terms and relative to the TRS of the SNL Equity REIT Index. The per unit fair value of each 2008 OPP Unit was estimated on the date of grant using the following assumptions in the Monte-Carlo valuation: expected price volatility for Boston Properties, Inc. and the SNL Equity REIT index of 25% and 20%, respectively; a risk free rate of 2.08%; and estimated total dividend payments over the measurement period of $8.23 per share.

In connection with the declaration of the special cash distributions of $5.98 per unit paid on January 30, 2008 to unitholders of record on December 31, 2007, Boston Properties, Inc.’s Board of Directors approved adjustments to all its outstanding stock option awards that were intended to ensure that its employees, directors and other persons who held such stock options were not disadvantaged by the special cash distribution. The exercise prices and number of all outstanding options were adjusted as of the close of business on the last trading day prior to the related “ex-dividend” date such that each option had the same fair value to the holder before and after giving effect to the payment of the special cash distribution. Accordingly, pursuant to the provisions of ASC 718, no compensation cost has been recognized in the Consolidated Statements of Operations in connection with such adjustments. As a result, effective as of the close of business on December 26, 2007, 2,131,556 outstanding stock options with a weighted-average exercise price of $37.42 were adjusted to 2,264,535 outstanding options with a weighted-average exercise price of $35.22. There were no other adjustments to the terms of the outstanding stock option awards.

A summary of the status of Boston Properties, Inc.’s stock options as of December 31, 2009, 2008 and 2007 and changes during the years ended December 31, 2009, 2008 and 2007 are presented below:


	Shares		Weighted Average Exercise Price
Outstanding at December 31, 2006	2,791,354		$	37.49
Granted	—			—
Exercised	(659,798	)	$	37.71
Canceled	—			—
Special Dividend Adjustment	132,979		$	35.22

Outstanding at December 31, 2007	2,264,535		$	35.22
Granted	—			—
Exercised	(1,058,133	)	$	36.36
Canceled	—			—

Outstanding at December 31, 2008	1,206,402		$	34.23
Granted	—			—
Exercised	(242,507	)	$	33.41
Canceled	—			—

Outstanding at December 31, 2009	963,895		$	34.44

The following table summarizes information about stock options outstanding at December 31, 2009:


Options Outstanding				Options Exercisable
Range of Exercise Prices	Number Outstanding at 12/31/09	Weighted-Average Remaining Contractual Life	Weighted-Average Exercise Price	Number Exercisable at 12/31/09	Weighted-Average Exercise Price
$32.62-$36.45	963,895	1.6 Years	$34.44	963,895	$34.44

The total intrinsic value of the outstanding and exercisable stock options as of December 31, 2009 was approximately $31.5 million. In addition, the Company had 1,206,402 and 2,264,535 options exercisable at weighted-average exercise prices of $34.23 and $35.22 at December 31, 2008 and 2007, respectively.

Boston Properties, Inc. adopted the 1999 Non-Qualified Employee Stock Purchase Plan (the “Stock Purchase Plan”) to encourage the ownership of Common Stock by eligible employees. The Stock Purchase Plan became effective on January 1, 1999 with an aggregate maximum of 250,000 shares of Common Stock available for issuance. The Stock Purchase Plan provides for eligible employees to purchase on the business day immediately following the end of the biannual purchase periods (i.e., January 1-June 30 and July 1-December 31) shares of Common Stock at a purchase price equal to 85% of the average closing prices of the Common Stock during the last ten business days of the purchase period. The Company issued 12,105, 7,755 and 6,166 shares with the weighted average purchase price equal to $42.65 per share, $80.80 per share and $90.98 per share under the Stock Purchase Plan during the years ended December 31, 2009, 2008 and 2007, respectively.

Selected Interim Financial Information (unaudited)

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Selected Interim Financial Information (unaudited)

18.

Selected Interim Financial Information (unaudited)

The tables below reflect the Company’s selected quarterly information for the years ended December 31, 2009 and 2008. The information provided has been revised for 2008 to reflect the adoption of (1) ASC 470-20 “Debt with Conversion and Other Options” (“ASC 470-20”) (formerly known as FSP No. APB 14-1) (See Note 8), (2) the guidance included in ASC 810 “Consolidation” (“ASC 810”) (formerly known as SFAS No. 160) and ASC 480-10-S99 “Distinguishing Liabilities from Equity” (“ASC 480-10-S99”) (formerly known as EITF Topic No. D-98) (See Note 11) and (3) the guidance included in ASC 260-10 “Earnings Per Share” (“ASC 260-10”) (formerly known as FSP EITF 03-06-1) (See Note 15).


	2009 Quarter Ended
	March 31,		June 30,		September 30,		December 31,
	(in thousands, except for per unit amounts)
Total revenue	$	377,544	$	389,490	$	377,303	$	377,912
Income from continuing operations	$	56,086	$	82,129	$	79,705	$	64,802
Net income attributable to Boston Properties Limited Partnership	$	54,586	$	80,466	$	77,819	$	63,479
Income attributable to Boston Properties Limited Partnership per unit—basic	$	0.39	$	0.55	$	0.49	$	0.40
Income attributable to Boston Properties Limited Partnership per unit—diluted	$	0.39	$	0.55	$	0.49	$	0.40


	2008 Quarter Ended
	March 31,		June 30,		September 30,		December 31,(1)
	(in thousands, except for per unit amounts)
Total revenue	$	371,432	$	368,680	$	357,988	$	390,300
Income (loss) from continuing operations	$	102,833	$	92,122	$	54,362	$	(110,569	)
Net income (loss) attributable to Boston Properties Limited Partnership	$	101,181	$	90,630	$	52,784	$	(112,070	)
Income (loss) attributable to Boston Properties Limited Partnership per unit—basic	$	0.72	$	0.65	$	0.38	$	(0.79	)
Income (loss) attributable to Boston Properties Limited Partnership per unit—diluted	$	0.72	$	0.64	$	0.37	$	(0.79	)

(1)	During the quarter ended December 31, 2008, the Company recognized non-cash impairment charges of approximately $188.3 million on certain of its investments in unconsolidated joint ventures.

Held for Sale/Discontinued Operations

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Held for Sale/Discontinued Operations

19.

Held for Sale/Discontinued Operations

The Company applies the provisions of ASC 360 “Property, Plant and Equipment” (“ASC 360”) (formerly known as SFAS No. 144 “Accounting for the Impairment or Disposal of Long Lived Assets”) The guidance in ASC 360 requires that long-lived assets that are to be disposed of by sale be measured at the lesser of (1) book value or (2) fair value less cost to sell. In addition, it requires that one accounting model be used for long-lived assets to be disposed of by sale and broadens the presentation of discontinued operations to include more disposal transactions.

On January 7, 2008, the Company transferred at cost Mountain View Research Park and Mountain View Technology Park to its Value-Added Fund for an aggregate of approximately $221.6 million. Due to the Company’s continuing involvement through its ownership interest in the Value-Added Fund, these properties have not been categorized as discontinued operations in the accompanying Consolidated Statements of Operations.

During the year ended December 31, 2007, the Company sold the following operating properties:

•

Orbital Sciences Campus and Broad Run Business Park, Building E, comprised of three Class A office properties aggregating approximately 337,000 net rentable square feet and an office/technical property totaling approximately 127,000 net rentable square feet, respectively, located in Loudon County, Virginia;

•

Democracy Center, a Class A office complex totaling approximately 685,000 net rentable square feet located in Bethesda, Maryland;

•

Newport Office Park, a Class A office property totaling approximately 172,000 net rentable square feet located in Quincy, Massachusetts;

•

Long Wharf Marriott, a 402-room hotel located in Boston, Massachusetts; and

•

5 Times Square, a Class A office property totaling approximately 1,102,000 net rentable square feet located in New York City.

Due to the Company’s continuing involvement in the management, for a fee, of 5 Times Square through an agreement with the buyer and other financial obligations to the buyer, 5 Times Square has not been categorized as discontinued operations in the accompanying Consolidated Statements of Operations. Due to the Company’s continuing involvement in the management, for a fee, of the Democracy Center property through an agreement with the buyer that was entered into at closing, this property is not categorized as discontinued operations in the accompanying Consolidated Statements of Operations. As a result, the gains on sales related to these properties have been reflected under the caption “Gains on sales of real estate and other assets” in the Consolidated Statements of Operations. The Company has presented the other properties listed above as discontinued operations in its Consolidated Statements of Operations for the year ended December 31, 2007.

The following table summarizes income from discontinued operations and the related realized gains on sales of real estate from discontinued operations for the years ended December 31, 2009, 2008 and 2007:


	For the Year Ended December 31,
	2009		2008		2007
	(in thousands)
Total revenue	$	—	$	—	$	19,665
Operating expenses		—		—		(9,443	)
Depreciation and amortization		—		—		(2,948	)

Income from discontinued operations	$	—	$	—	$	7,274

Gains on sales of real estate from discontinued operations	$	—	$	—	$	266,817

The Company’s application of ASC 360 results in the presentation of the net operating results of these qualifying properties sold during 2007 as income from discontinued operations. In addition, ASC 360 results in the gains on sale of these qualifying properties totaling approximately $266.8 million to be reflected as gains on sales of real estate from discontinued operations in the accompanying Consolidated Statements of Operations for the year ended December 31, 2007. The application of ASC 360 does not have an impact on net income attributable to Boston Properties Limited Partnership. ASC 360 only impacts the presentation of these properties within the Consolidated Statements of Operations.

Newly Issued Accounting Standards

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Newly Issued Accounting Standards

20.

Newly Issued Accounting Standards

In June 2008, the FASB ratified the guidance included in ASC 815-40 “Derivatives and Hedging” (“ASC 815-40”) (formerly known as EITF Issue No. 07-5, “Determining Whether an Instrument (or an Embedded Feature) Is Indexed to an Entity’s Own Stock” (“EITF No. 07-5”)). The guidance included in ASC 815-40 requires entities to apply a two-step approach to evaluate whether an equity-linked financial instrument (or embedded feature) is indexed to its own stock. The guidance included in ASC 815-40 was effective on January 1, 2009. The adoption of the guidance included in ASC 815-40 did not have a material impact on the Company.

In April 2009, the FASB issued ASC 820-10-65-4 “Transition Related to FASB Staff Position FAS 157-4, Determining Fair Value When the Volume and Level of Activity for the Asset or Liability Have Significantly Decreased and Identifying Transactions That Are Not Orderly” (“ASC 820-10-65-4”) (formerly known as FSP No. 157-4, “Determining Fair Value When the Volume and Level of Activity for the Asset or Liability Have Significantly Decreased and Identifying Transactions That Are Not Orderly” (“FSP FAS 157-4”)). ASC 820-10-65-4 provides additional guidance for estimating fair value in accordance with ASC 820-10 when the volume and level of activity for the asset or liability have significantly decreased. ASC 820-10-65-4 also includes guidance on identifying circumstances that indicate a transaction is not orderly. ASC 820-10-65-4 was effective for interim and annual reporting periods ending after June 15, 2009. The adoption of ASC 820-10-65-4 did not have a material impact on the Company’s financial position or results of operations.

In June 2009, the FASB issued SFAS No. 167, “Amendments to FASB Interpretation No. 46(R)” (“SFAS No. 167”), which modifies the approach to determining the primary beneficiary of a variable interest entity (“VIE”) and requires companies to more frequently assess whether they must consolidate a VIE. SFAS No. 167 is effective on the first annual reporting period that begins after November 15, 2009. The Company is currently assessing the potential impact that the adoption of SFAS No. 167 will have on its financial statements.

In June 2009, the FASB issued SFAS No. 168, “The FASB Accounting Standards Codification^™ and the Hierarchy of Generally Accepted Accounting Principles-a replacement of FASB Statement No. 162” (“SFAS No. 168”), which establishes the FASB Accounting Standards Codification (the “Codification”) as the source of authoritative U.S. generally accepted accounting principles (GAAP) recognized by the FASB to be applied by nongovernmental entities. Rules and interpretive releases of the Securities and Exchange Commission (SEC) under authority of federal securities laws are also sources of authoritative GAAP for SEC registrants. On the effective date of this Statement, the Codification superseded all then-existing non-SEC accounting and reporting standards. SFAS No. 168 was effective for financial statements issued for interim and annual periods ending after September 15, 2009. The adoption of SFAS No. 168 did not have a material impact on the Company.

Related Party Transactions

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Related Party Transactions

21.

Related Party Transactions

On October 26, 2005, the Company entered into an agreement with an entity owned by Mr. Zuckerman, Chairman of the Board of Directors of Boston Properties, Inc. Under the agreement, which was approved by the disinterested members of the Board of Directors of Boston Properties, Inc., the Company rendered project management services to such entity in exchange for a fee. The Company extended its services under a letter dated October 10, 2006. Under the agreement, as extended, the Company earned $0, $0 and $80,000 during the years ended December 31, 2009, 2008 and 2007, respectively.

A firm controlled by Mr. Raymond A. Ritchey’s brother was paid aggregate leasing commissions of approximately $257,000, $2,219,000 and $848,000 for the years ended December 31, 2009, 2008 and 2007, respectively, related to certain exclusive leasing arrangements for certain Northern Virginia properties. Mr. Ritchey is an Executive Vice President of Boston Properties, Inc.

Mr. Martin Turchin, a member of the Board of Directors of Boston Properties, Inc., is a non-executive/non-director Vice Chairman of CB Richard Ellis (“CBRE”). Through an arrangement with CBRE and its predecessor, Insignia/ESG, Inc. that has been in place since 1985, Mr. Turchin and Turchin & Associates, an entity owned by Mr. Turchin (95%) and his son (5%), participate in brokerage activities for which CBRE is retained as leasing agent, some of which involve leases for space within buildings owned by the Company. Additionally, Mr. Turchin’s son is employed by CBRE and works on transactions for which CBRE earns commission income from the Company. Mr. Turchin’s son’s compensation from CBRE is in the form of salary and bonus, neither of which is directly tied to CBRE’s transactions with the Company. For the years ended December 31, 2009, 2008 and 2007, Mr. Turchin, directly and through Turchin & Associates, received commission income of $29,000, $138,000 and $95,000, respectively, from commissions earned by CBRE and its predecessor, Insignia/ESG, Inc., from the Company. Pursuant to its arrangement with CBRE, Turchin & Associates has confirmed to the Company that it is paid on the same basis with respect to properties owned by the Company as it is with respect to properties owned by other clients of CBRE. Mr. Turchin does not participate in any discussions or other activities relating to the Company’s contractual arrangements with CBRE either in his capacity as a member of the Board of Directors of Boston Properties, Inc. or as a Vice Chairman of CBRE.

On June 30, 1998, the Company acquired from entities controlled by Mr. Alan B. Landis, a former director, a portfolio of properties known as the Carnegie Center Portfolio and Tower Center One and related operations and development rights (collectively, the “Carnegie Center Portfolio”). In connection with the acquisition of the Carnegie Center Portfolio, the Company entered into a development agreement (the “Development Agreement”) with affiliates of Mr. Landis providing for up to approximately 2,000,000 square feet of development in or adjacent to the Carnegie Center office complex. An affiliate of Mr. Landis was entitled to a purchase price for each parcel developed under the Development Agreement calculated on the basis of $20 per rentable square foot of property developed. Another affiliate of Mr. Landis was eligible to earn a contingent payment for each developed property that achieves a stabilized return in excess of a target annual return ranging between 10.5% and 11%. The Development Agreement also provided that upon negotiated terms and conditions, the Company and Mr. Landis would form a development company to provide development services for these development projects and would share the expenses and profits, if any, of this new company. In addition, in connection with the acquisition of the Carnegie Center Portfolio, Mr. Landis became a director of Boston Properties, Inc. pursuant to an Agreement Regarding Directorship, dated as of June 30, 1998, with Boston Properties, Inc. (the “Directorship Agreement”). Under the Directorship Agreement, Boston Properties, Inc. agreed to nominate Mr. Landis for re-election as a director at each annual meeting of stockholders of Boston Properties, Inc. in a year in which his term expires, provided that specified conditions are met.

On October 21, 2004, the Company entered into an agreement (the “2004 Agreement”) to modify several provisions of the Development Agreement. Under the terms of the 2004 Agreement, the Company and affiliates of Mr. Landis amended the Development Agreement to limit the rights of Mr. Landis and his affiliates to participate in the development of properties under the Development Agreement. Among other things, Mr. Landis agreed that (1) Mr. Landis and his affiliates will have no right to participate in any entity formed to acquire land parcels or the development company formed by the Company to provide development services under the Development Agreement, (2) Mr. Landis will have no right or obligation to play a role in development activities engaged in by the development company formed by the Company under the Development Agreement or receive compensation from the development company and (3) the affiliate of Mr. Landis will have no right to receive a contingent payment for developed properties based on stabilized returns. In exchange, the Company (together with Boston Properties, Inc.) agreed to:

•

effective as of June 30, 1998, pay Mr. Landis $125,000 on January 1 of each year until the earlier of (A) January 1, 2018, (B) the termination of the Development Agreement or (C) the date on which all development properties under the Development Agreement have been conveyed pursuant to the Development Agreement, with $750,000, representing payments of this annual amount from 1998 to 2004, being paid upon execution of the 2004 Agreement; and

•

pay an affiliate of Mr. Landis, in connection with the development of land parcels acquired under the Development Agreement, an aggregate fixed amount of $10.50 per rentable square foot of property developed (with a portion of this amount (i.e., $5.50) being subject to adjustment, in specified circumstances, based on future increases in the Consumer Price Index) in lieu of a contingent payment based on stabilized returns, which payment could have been greater or less than $10.50 per rentable square foot of property developed.

The Company also continues to be obligated to pay an affiliate of Mr. Landis the purchase price of $20 per rentable square foot of property developed for each land parcel acquired as provided in the original Development Agreement. During the 20-year term of the Development Agreement, until such time, if any, as the Company elects to acquire a land parcel, an affiliate of Mr. Landis will remain responsible for all carrying costs associated with such land parcel. On July 24, 2007, the Company acquired from Mr. Landis 701 Carnegie Center, a land parcel located in Princeton, New Jersey for a purchase price of approximately $3.1 million.

In addition, in connection with entering into the 2004 Agreement, Mr. Landis resigned as a director of Boston Properties, Inc. effective as of May 11, 2005 and agreed that Boston Properties, Inc. had no future obligation to nominate Mr. Landis as a director of Boston Properties, Inc. under the Directorship Agreement or otherwise. Mr. Landis did not resign because of a disagreement with Boston Properties, Inc. on any matter relating to its operations, policies or practices. Mitchell S. Landis, the Senior Vice President and Regional Manager of the Company’s Princeton, New Jersey region, is the brother of Alan B. Landis.

In accordance with Boston Properties, Inc.’s 1997 Plan, and as approved by the Board of Directors of Boston Properties, Inc., seven non-employee directors made an election to receive deferred stock units in lieu of cash fees for 2009. The deferred stock units will be settled in shares of common stock upon the cessation of such director’s service on the Board of Directors of Boston Properties, Inc. As a result of these elections, the aggregate cash fees otherwise payable to a non-employee director during a fiscal quarter are converted into a number of deferred stock units equal to the aggregate cash fees divided by the last reported sales price of a share of Boston Properties, Inc.’s common stock on the last trading of the applicable fiscal quarter. The deferred stock units are also credited with dividend equivalents as dividends are paid by Boston Properties, Inc. At December 31, 2009 and 2008, Boston Properties, Inc. had outstanding 87,302 and 72,580 deferred stock units, respectively.

Subsequent Events

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Subsequent Events

22.

Subsequent Events

In May 2009, the FASB issued ASC 855-10 “Subsequent Events” (“ASC 855-10”) (formerly known as SFAS No. 165 “Subsequent Events” (“SFAS No. 165”)), which establishes general standards of accounting and disclosure for events that occur after the balance sheet date but before the financial statements are issued. The guidance included in ASC 855-10 was effective for interim or annual periods beginning after June 15, 2009. The Company has evaluated subsequent events through the time of filing these financial statements with the SEC on Form 10-K on February 25, 2010.

On January 19, 2010, the Company paid $12.8 million related to the termination of a lease for its 250 West 55th Street project in New York City. The Company announced in February 2009 that it was suspending construction of the 1,000,000 square foot office project. During the first quarter of 2009, the Company recognized costs aggregating approximately $27.8 million related to the suspension of development, which amount included a $20.0 million contractual amount due pursuant to a lease agreement.

On January 29, 2010, Boston Properties, Inc. issued 66,461 shares of restricted stock and the Company issued 248,833 LTIP Units under the 1997 Plan to certain employees of the Company.

Schedule 3-Real Estate and Accumulated Depreciation

12 Months Ended

Dec. 31, 2009

Statement [Line Items]

Schedule 3-Real Estate and Accumulated Depreciation

Boston Properties Limited Partnership

Schedule 3—Real Estate and Accumulated Depreciation

December 31, 2009

(dollars in thousands)


Property Name						Original						Costs Capitalized Subsequent to Acquisition			Land and Improvements			Building and Improvements		Land Held for Development			Development and Construction in Progress			Total		Accumulated Depreciation		Year(s) Built/ Renovated	Depreciable Lives (Years)
	Type	Location	Encumbrances			Land			Building			Costs Capitalized Subsequent to Acquisition			Land and Improvements			Building and Improvements		Land Held for Development			Development and Construction in Progress			Total		Accumulated Depreciation		Year(s) Built/ Renovated	Depreciable Lives (Years)
Embarcadero Center	Office	San Francisco, CA	$	375,000		$	179,697		$	847,410		$	201,046		$	180,417		$	1,047,736	$	—		$	—		$	1,228,153	$	319,926	1970/1989	(1	)
399 Park Avenue	Office	New York, NY		—			339,200			700,358			18,015			339,200			718,373		—			—			1,057,573		130,805	1961	(1	)
Prudential Center	Office	Boston, MA		—			92,077			734,594			209,235			92,328			928,294		15,284			—			1,035,906		271,512	1965/1993/2002	(1	)
601 Lexington Avenue (Citigroup Center)	Office	New York, NY		467,034			241,600			494,782			147,333			279,281			604,434		—			—			883,715		122,587	1977/1997	(1	)
Times Square Tower	Office	New York, NY		—			165,413			380,438			44,803			160,995			429,659		—			—			590,654		78,084	2004	(1	)
Carnegie Center	Office	Princeton, NJ		56,306			105,107			377,259			39,418			98,731			421,383		1,670			—			521,784		121,175	1983-1999	(1	)
599 Lexington Avenue	Office	New York, NY		750,000			81,040			100,507			87,324			81,040			187,831		—			—			268,871		120,292	1986	(1	)
Gateway Center	Office	San Francisco, CA		—			28,255			139,245			42,857			29,029			181,328		—			—			210,357		51,213	1984/1986/2002	(1	)
South of Market	Office	Reston, VA		187,377			13,603			164,144			3,216			13,603			167,360		—			—			180,963		10,365	2008	(1	)
Reservoir Place	Office	Waltham, MA		50,000			18,605			92,619			25,159			19,099			117,284		—			—			136,383		41,542	1955/1987	(1	)
Kingstowne Towne Center	Office	Alexandria, VA		59,387			18,021			109,038			(484	)		18,021			108,554		—			—			126,575		11,860	2003-2006	(1	)
3200 Zanker Road	Office	San Jose, CA		—			36,705			82,863			6,405			36,705			88,141		1,127			—			125,973		11,447	1988	(1	)
505 9th Street	Office	Washington, DC		129,843			38,885			83,719			2,260			38,885			85,979		—			—			124,864		7,159	2007	(1	)
1333 New Hampshire Avenue	Office	Washington, DC		—			34,032			85,660			1,989			34,032			87,649		—			—			121,681		20,287	1996	(1	)
1330 Connecticut Avenue	Office	Washington, DC		47,721			25,982			82,311			10,872			25,982			93,183		—			—			119,165		16,333	1984	(1	)
635 Massachusetts Avenue	Office	Washington, DC		—			95,281			22,221			15			95,281			22,221		—			15			117,517		5,203	1968/1992	(1	)
Capital Gallery	Office	Washington, DC		—			4,725			29,565			78,347			6,128			106,509		—			—			112,637		38,216	1981/2006	(1	)
One Freedom Square	Office	Reston, VA		71,266			9,929			84,504			7,119			9,883			91,669		—			—			101,552		30,434	2000	(1	)
Seven Cambridge Center	Office	Cambridge, MA		—			3,457			97,136			210			3,457			97,346		—			—			100,803		23,421	2006	(1	)
Two Freedom Square	Office	Reston, VA		—			13,930			77,739			6,196			13,866			83,999		—			—			97,865		23,160	2001	(1	)
One and Two Reston Overlook	Office	Reston, VA		—			16,456			66,192			4,490			16,456			70,682		—			—			87,138		22,534	1999	(1	)
140 Kendrick Street	Office	Needham, MA		53,849			18,095			66,905			256			18,095			67,161		—			—			85,256		9,802	2000	(1	)
Discovery Square	Office	Reston, VA		—			11,198			71,782			586			11,146			72,420		—			—			83,566		19,570	2001	(1	)
12310 Sunrise Valley Drive	Office	Reston, VA		—			9,367			67,431			5,397			10,542			71,653		—			—			82,195		20,654	1987/1988	(1	)
77 CityPoint	Office	Waltham, MA		—			13,847			60,383			2,989			13,847			63,372		—			—			77,219		2,718	2008	(1	)
Five Cambridge Center	Office	Cambridge, MA		—			18,863			53,346			4,296			18,863			57,642		—			—			76,505		7,529	1981/1996	(1	)
Waltham Weston Corporate Center	Office	Waltham, MA		—			10,385			60,694			5,143			10,350			65,872		—			—			76,222		19,964	2003	(1	)
12300 Sunrise Valley Drive	Office	Reston, VA		—			9,062			58,884			5,489			10,235			63,105		95			—			73,435		18,106	1987/1988	(1	)
Democracy Tower	Office	Reston, VA		58,875			—			73,335			—			—			73,335		—			—			73,335		1,077	2009	(1	)
North First Business Park	Office	San Jose, CA		—			58,402			13,069			1,765			23,371			14,155		35,710			—			73,236		3,255	1981	(1	)
Four Cambridge Center	Office	Cambridge, MA		—			19,104			52,078			1,292			19,104			53,370		—			—			72,474		5,471	1983/1998	(1	)
230 CityPoint	Office	Waltham, MA		—			13,189			49,823			7,316			13,189			57,139		—			—			70,328		9,169	1992	(1	)
Reston Corporate Center	Office	Reston, VA		—			9,135			50,857			3,027			9,496			53,523		—			—			63,019		14,812	1984	(1	)
New Dominion Technology Park, Bldg. Two	Office	Herndon, VA		63,000			5,584			51,868			(73	)		5,574			51,805		—			—			57,379		9,188	2004	(1	)
Wisconsin Place	Office	Chevy Chase, MD	97,169		—		53,349		—			—		53,349	—		—		53,349	837		2009		(1	)
191 Spring Street	Office	Lexington, MA	—		2,850		27,166		21,151			2,850		48,317	—		—		51,167	28,812		1971/1995		(1	)
303 Almaden Boulevard	Office	San Jose, CA	—		10,836		35,606		3,424			10,836		39,030	—		—		49,866	4,631		1995		(1	)
New Dominion Technology Park, Bldg. One	Office	Herndon, VA	50,967		3,880		43,227		1,047			3,880		44,274	—		—		48,154	12,977		2001		(1	)
One Preserve Parkway	Office	Rockville, MD	—		5,357		42,186		—			5,357		42,186	—		—		47,543	1,328		2009		(1	)
1301 New York Avenue	Office	Washington, DC	—		9,250		18,750		18,027			9,250		36,777	—		—		46,027	12,694		1983/1998		(1	)
Sumner Square	Office	Washington, DC	25,495		624		28,745		12,970			958		41,381	—		—		42,339	16,142		1985		(1	)
200 West Street	Office	Waltham, MA	—		16,148		24,983		818			16,148		25,801	—		—		41,949	9,951		1999		(1	)
University Place	Office	Cambridge, MA	18,422		—		37,091		4,119			27		41,183	—		—		41,210	14,800		1985		(1	)
Bedford Business Park	Office	Bedford, MA	—		534		3,403		36,369			1,773		38,533	—		—		40,306	20,146		1980		(1	)
Quorum Office Park	Office	Chelmsford, MA	—		3,750		32,454		3,478			4,762		34,920	—		—		39,682	8,727		2001		(1	)
2600 Tower Oaks Boulevard	Office	Rockville, MD	—		4,243		31,125		3,872			4,244		34,996	—		—		39,240	11,365		2001		(1	)
12290 Sunrise Valley Drive	Office	Reston, VA	—		3,594		32,977		(286	)		3,594		32,691	—		—		36,285	5,017		2006		(1	)
One Cambridge Center	Office	Cambridge, MA	—		134		25,110		8,916			134		34,026	—		—		34,160	19,926		1987		(1	)
500 E Street	Office	Washington, DC	—		109		22,420		8,484			1,569		29,444	—		—		31,013	16,722		1987		(1	)
Eight Cambridge Center	Office	Cambridge, MA	22,910		850		25,042		110			822		25,180	—		—		26,002	6,681		1999		(1	)
10 and 20 Burlington Mall Road	Office	Burlington, MA	18,524		930		6,928		12,160			652		19,366	—		—		20,018	11,956		1984-1989/95-96		(1	)
Ten Cambridge Center	Office	Cambridge, MA	—		1,299		12,943		4,003			1,868		16,377	—		—		18,245	8,743		1990		(1	)
Montvale Center	Office	Gaithersburg, MD	25,000		1,574		9,786		5,942			2,399		14,903	—		—		17,302	8,544		1987		(1	)
40 Shattuck Road	Office	Andover, MA	—		709		14,740		1,568			709		16,308	—		—		17,017	4,206		2001		(1	)
201 Spring Street	Office	Lexington, MA	—		2,849		15,303		(1,245	)		2,849		14,058	—		—		16,907	4,050		1997		(1	)
Lexington Office Park	Office	Lexington, MA	—		998		1,426		14,012			1,073		15,363	—		—		16,436	9,656		1982		(1	)
6601 & 6605 Springfield Center Drive	Office	Springfield, VA	—		14,041		2,375		(160	)		13,866		2,375	15		—		16,256	1,417		1990		(1	)
Three Cambridge Center	Office	Cambridge, MA	—		174		12,200		3,342			174		15,542	—		—		15,716	8,961		1987		(1	)
103 4th Avenue	Office	Waltham, MA	—		11,911		2,507		—			11,911		2,507	—		—		14,418	1,691		1961		(1	)
92-100 Hayden Avenue	Office	Lexington, MA	—		594		6,748		6,087			619		12,810	—		—		13,429	6,762		1985		(1	)
181 Spring Street	Office	Lexington, MA	—		1,066		9,520		2,791			1,066		12,311	—		—		13,377	3,757		1999		(1	)
Waltham Office Center	Office	Waltham, MA	—		422		2,719		7,417			425		7,957	2,176		—		10,558	6,091		1968-1970/87-88		(1	)
91 Hartwell Avenue	Office	Lexington, MA	15,156		784		6,464		2,956			784		9,420	—		—		10,204	5,912		1985		(1	)
7501 Boston Boulevard, Building Seven	Office	Springfield, VA	—		665		9,273		39			665		9,312	—		—		9,977	2,887		1997		(1	)
195 West Street	Office	Waltham, MA	—		1,611		6,652		1,562			1,611		8,214	—		—		9,825	4,315		1990		(1	)
33 Hayden Avenue	Office	Lexington, MA	—		266		3,234		5,405			266		8,639	—		—		8,905	5,652		1979		(1	)
Eleven Cambridge Center	Office	Cambridge, MA	—		121		5,535		3,134			121		8,669	—		—		8,790	5,541		1984		(1	)
7450 Boston Boulevard, Building Three	Office	Springfield, VA	—		1,165		4,681		1,478			1,327		5,997	—		—		7,324	2,159		1987		(1	)
7435 Boston Boulevard, Building One	Office	Springfield, VA	—		392		3,822		2,853			486		6,581	—		—		7,067	4,101		1982		(1	)
8000 Grainger Court, Building Five	Office	Springfield, VA	—		366		4,282		2,292			453		6,487	—		—		6,940	4,103		1984		(1	)
7500 Boston Boulevard, Building Six	Office	Springfield, VA	—		138		3,749		1,568			273		5,182	—		—		5,455	3,307		1985		(1	)
7300 Boston Boulevard, Building Thirteen	Office	Springfield, VA	—		608		4,773		—			608		4,773	—		—		5,381	2,510		2002		(1	)
7601 Boston Boulevard, Building Eight	Office	Springfield, VA	—		200		878		4,182			378		4,882	—		—		5,260	2,867		1986		(1	)
Fourteen Cambridge Center	Office	Cambridge, MA	—		110		4,483		569			110		5,052	—		—		5,162	3,204		1983		(1	)
8000 Corporate Court, Building Eleven	Office	Springfield, VA	—		136		3,071		971			687		3,491	—		—		4,178	1,805		1989		(1	)
7375 Boston Boulevard, Building Ten	Office	Springfield, VA	—		23		2,685		955			47		3,616	—		—		3,663	1,936		1988		(1	)
7374 Boston Boulevard, Building Four	Office	Springfield, VA	—		241		1,605		1,265			303		2,808	—		—		3,111	1,749		1984		(1	)
7451 Boston Boulevard, Building Two	Office	Springfield, VA	—		249		1,542		1,000			535		2,256	—		—		2,791	1,879		1982		(1	)
32 Hartwell Avenue	Office	Lexington, MA	—		168		1,943		660			168		2,603	—		—		2,771	2,353		1968-1979/1987		(1	)
164 Lexington Road	Office	Billerica, MA	—		592		1,370		212			592		1,582	—		—		2,174	609		1982		(1	)
17 Hartwell Avenue	Office	Lexington, MA		—				26			150			1,240		26			1,390		—			—			1,416		886	1968	(1	)
Cambridge Center Marriott	Hotel	Cambridge, MA		—				478			37,918			23,741		478			61,659		—			—			62,137		33,205	1986	(1	)
Cambridge Center East Garage	Garage	Cambridge, MA		—				—			35,035			1,073		—			36,108		—			—			36,108		2,805	1984	(1	)
Cambridge Center West Garage	Garage	Cambridge, MA		—				1,256			15,697			69		1,256			15,766		—			—			17,022		1,663	2006	(1	)
Cambridge Center North Garage	Garage	Cambridge, MA		—				1,163			11,633			1,085		1,163			12,718		—			—			13,881		6,388	1990	(1	)
Atlantic Wharf (Russia Wharf)	Development	Boston, MA		—				—			—			371,984		—			—		—			371,984			371,984		—	Various	N/A
2200 Pennsylvania Avenue	Development	Washington, DC		—				—			—			99,340		—			—		—			99,340			99,340		—	Various	N/A
Weston Corporate Center	Development	Weston, MA		—				—			—			92,306		—			—		—			92,306			92,306		—	Various	N/A
250 West 55th Street	Land	New York, NY		—				—			—			472,293		—			—		472,293			—			472,293		—	Various	N/A
Plaza at Almaden	Land	San Jose, CA		—				—			—			32,686		—			—		32,686			—			32,686		—	Various	N/A
Springfield Metro Center	Land	Springfield, VA		—				—			—			28,888		—			—		28,888			—			28,888		—	Various	N/A
Tower Oaks Master Plan	Land	Rockville, MD		—				—			—			28,309		—			—		28,309			—			28,309		—	Various	N/A
Prospect Hill	Land	Waltham, MA		—				—			—			23,605		—			—		23,605			—			23,605		—	Various	N/A
Washingtonian North	Land	Gaithersburg, MD		—				—			—			17,629		—			—		17,629			—			17,629		—	Various	N/A
17 Cambridge Center	Land	Cambridge, MA		—				—			—			17,350		—			—		17,350			—			17,350		—	Various	N/A
Reston Gateway	Land	Reston, VA		—				—			—			9,312		—			—		9,312			—			9,312		—	Various	N/A
Reston Eastgate	Land	Reston, VA		—				—			—			9,300		—			—		9,300			—			9,300		—	Various	N/A
Crane Meadow	Land	Marlborough, MA		—				—			—			8,720		—			—		8,720			—			8,720		—	Various	N/A
Broad Run Business Park	Land	Loudon County, VA		—				—			—			7,617		1,621			—		5,996			—			7,617		—	Various	N/A
Cambridge Master Plan	Land	Cambridge, MA		—				—			—			3,439		—			128		3,311			—			3,439		—	Various	N/A
30 Shattuck Road	Land	Andover, MA		—				—			—			1,144		—			—		1,144			—			1,144		—	Various	N/A

			$	2,643,301	(2)		$	1,867,715		$	6,334,063		$	2,433,955	$	1,874,004		$	7,483,464	$	714,620		$	563,645		$	10,635,733	$	1,987,296

The aggregate cost and accumulated depreciation for tax purposes was approximately $12.3 billion and $1.9 billion, respectively.

(1)	Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years.

(2)	Includes fair value adjustment of approximately $9.1 million.

Boston Properties Limited Partnership

Real Estate and Accumulated Depreciation

December 31, 2009

(dollars in thousands)

A summary of activity for real estate and accumulated depreciation is as follows:


	2009			2008			2007
Real Estate:
Balance at the beginning of the year	$	10,162,132		$	9,813,376		$	9,226,895
Additions to/improvements of real estate		481,237			598,992			1,316,238
Assets sold/written-off		(7,636	)		(250,236	)		(729,757	)

Balance at the end of the year	$	10,635,733		$	10,162,132		$	9,813,376

Accumulated Depreciation:
Balance at the beginning of the year	$	1,731,063		$	1,503,283		$	1,406,407
Depreciation expense		261,171			250,764			237,296
Assets sold/written-off		(4,938	)		(22,984	)		(140,420	)

Balance at the end of the year	$	1,987,296		$	1,731,063		$	1,503,283

Note: Real Estate and Accumulated Depreciation amounts do not include Furniture, Fixtures and Equipment.

Document Information	12 Months Ended
Document Information	Dec. 31, 2009
Statement [Line Items]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2009

Entity Information - USD ($)	12 Months Ended
Entity Information - USD ($)	Dec. 31, 2009	Jan. 01, 2010	Jun. 30, 2009
Statement [Line Items]
Entity Registrant Name	BOSTON PROPERTIES LTD PARTNERSHIP
Entity Central Index Key	0001043121
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		0
Entity Public Float			$ 0