| SEC Schedule, 12-28, Real Estate Companies, Investment in Real Estate and Accumulated Depreciation Disclosure [Text Block] | Item 15. Exhibits and Financial Statement Schedules. (a) Financial Statement Schedule Boston Properties, Inc. Schedule 3—Real Estate and Accumulated Depreciation December 31, 2023 (dollars in thousands) Property Name Type Location Encumbrances 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 Year(s) Acquired Depreciable Lives (Years) Land Building 767 Fifth Avenue (the General Motors Building) Office New York, NY $ 2,288,004 $ 1,796,252 $ 1,532,654 $ 365,829 $ 1,796,252 $ 1,898,483 $ — $ — $ 3,694,735 $ 507,660 1968/2019 2013 (1) Prudential Center Office Boston, MA — 92,077 948,357 791,280 115,634 1,687,021 — 29,059 1,831,714 774,225 1965/1993/2002/2016-2017 1998/1999/2000 (1) Embarcadero Center Office San Francisco, CA — 179,697 847,410 524,483 195,986 1,355,604 — — 1,551,590 781,405 1970/1989 1998-1999 (1) 399 Park Avenue Office New York, NY — 339,200 700,358 408,846 354,107 1,094,297 — — 1,448,404 482,752 1961/2018 2002 (1) 601 Lexington Avenue Office New York, NY 989,181 241,600 494,782 545,612 289,639 992,355 — — 1,281,994 372,795 1977/1997/2021 2001 (1) Salesforce Tower Office San Francisco, CA — 200,349 946,205 7,623 200,349 953,828 — — 1,154,177 159,274 2018 2013 (1) 200 Clarendon Street and Garage Office Boston, MA — 219,543 667,884 251,372 250,910 887,889 — — 1,138,799 338,529 1976 2010 (1) 250 West 55th Street Office New York, NY — 285,263 603,167 52,917 285,263 656,084 — — 941,347 198,081 2014 2007 (1) 100 Federal Street Office Boston, MA — 131,067 435,954 127,199 131,067 563,153 — — 694,220 172,079 1971-1975/2017 2012 (1) Times Square Tower Office New York, NY — 165,413 380,438 140,281 169,193 516,939 — — 686,132 256,942 2004 2000 (1) Madison Centre Office Seattle, WA — 104,641 564,336 4,082 104,641 568,418 — — 673,059 35,516 2017 2022 (1) Carnegie Center Office Princeton, NJ — 142,666 316,856 177,545 94,243 484,024 58,800 — 637,067 267,232 1983-2016 1998/1999/2000/2007/2014/2017/2019 (1) Santa Monica Business Park Office Los Angeles, CA 295,649 46,360 410,421 164,229 210,471 410,535 4 — 621,010 865 1976-1980 2023 (1) 125 Broadway Office Cambridge, MA — 126,364 433,662 4,000 126,364 437,662 — — 564,026 20,717 2000 2022 (1) Reston Next Office Reston, VA — 35,549 525,277 — 2,901 557,925 — — 560,826 32,504 2022 1998 (1) Atlantic Wharf Office Boston, MA — 63,988 454,537 39,399 63,988 493,936 — — 557,924 180,686 2011 2007 (1) 2100 Pennsylvania Avenue Office Washington, DC — 185,203 324,206 — 185,203 324,206 — — 509,409 20,768 2023 N/A (1) 599 Lexington Avenue Office New York, NY — 81,040 100,507 258,659 87,852 352,354 — — 440,206 197,429 1986 1997 (1) Fountain Square Office Reston, VA — 56,853 306,298 49,874 56,853 356,172 — — 413,025 111,481 1986-1990 2012 (1) 510 Madison Avenue Office New York, NY — 103,000 253,665 33,100 103,000 286,765 — — 389,765 104,052 2012 2010 (1) 325 Main Street Office Cambridge, MA — (2) 21,596 312,492 30,933 21,596 343,425 — — 365,021 14,833 2022 1997 (1) 680 Folsom Street Office San Francisco, CA — 72,545 219,766 8,026 72,545 227,792 — — 300,337 80,964 2014 2012 (1) 145 Broadway Office Cambridge, MA — 121 273,013 26,359 23,367 276,126 — — 299,493 35,390 2019 1997 (1) 2200 Pennsylvania Avenue Office Washington, DC — — 183,541 114,090 102,979 194,652 — — 297,631 77,357 2011 2008 (1) South of Market and Democracy Tower Office Reston, VA — 13,603 237,479 30,952 13,687 268,347 — — 282,034 108,973 2008-2009 2003 (1) Bay Colony Corporate Center Office Waltham, MA — 18,789 148,451 96,639 18,789 240,416 4,674 — 263,879 113,123 1985-1989 2011 (1) 535 Mission Street Office San Francisco, CA — 40,933 148,378 4,629 40,934 153,006 — — 193,940 46,615 2015 2013 (1) Boston Properties, Inc. Schedule 3—Real Estate and Accumulated Depreciation December 31, 2023 (dollars in thousands) Property Name Type Location Encumbrances 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 Year(s) Acquired Depreciable Lives (Years) Land Building Mountain View Research Park Office Mountain View, CA — 95,066 68,373 21,069 95,066 89,442 — — 184,508 33,095 1977-1981/2007-2013 2013 (1) Reservoir Place Office Waltham, MA — 18,605 104,124 56,160 20,108 156,954 1,827 — 178,889 90,808 1955/1987/2017 1997/1998 (1) 140 Kendrick Street Office Needham, MA — 18,095 66,905 71,861 19,092 137,769 — — 156,861 46,586 2000 2004 (1) 1330 Connecticut Avenue Office Washington, DC — 25,982 82,311 39,924 27,135 121,082 — — 148,217 53,332 1984/2018 2004 (1) 880 Winter Street Office Waltham, MA — 15,597 37,255 95,265 15,597 132,520 — — 148,117 10,056 1998/2022 2019 (1) One Freedom Square Office Reston, VA — 9,929 84,504 48,985 11,293 132,125 — — 143,418 68,406 2000 2003 (1) Two Freedom Square Office Reston, VA — 13,930 77,739 45,068 15,420 121,317 — — 136,737 44,662 2001 2003 (1) Kingstowne Towne Center Office Alexandria, VA — 18,021 109,038 4,665 18,062 113,662 — — 131,724 54,480 2003-2006 2007 (1) One and Two Reston Overlook Office Reston, VA — 16,456 66,192 45,224 16,179 111,693 — — 127,872 61,572 1999 2000 (1) Shady Grove Innovation District Office Rockville, MD — 52,030 64,212 10,676 26,834 34,954 65,130 — 126,918 4,701 1968-1985 2021 (1) Weston Corporate Center Office Weston, MA — 25,753 92,312 1,038 25,854 93,249 — — 119,103 41,485 2010 2001 (1) 355 Main Street Office Cambridge, MA 593,545 18,863 53,346 41,772 21,173 92,808 — — 113,981 36,957 1981/1996/2013 2006 (1) 17Fifty Presidents Street Office Reston, VA — — 113,362 162 — 113,524 — — 113,524 16,624 2020 2013 (1) 200 West Street Office Waltham, MA — 16,148 24,983 71,199 16,813 95,160 357 — 112,330 28,192 1999/2021 1997 (1) Discovery Square Office Reston, VA — 11,198 71,782 21,744 12,533 92,191 — — 104,724 57,015 2001 2003 (1) 10 CityPoint Office Waltham, MA — 1,953 85,752 7,571 2,288 92,988 — — 95,276 24,003 2016 1997 (1) 90 Broadway Office Cambridge, MA — (2) 19,104 52,078 22,742 20,785 73,139 — — 93,924 31,538 1983/1998/2013 2006 (1) Waltham Weston Corporate Center Office Waltham, MA — 10,385 60,694 20,705 11,097 80,687 — — 91,784 45,601 2003 1999 (1) 153 & 211 Second Avenue Office Waltham, MA — 33,233 55,940 718 33,233 55,940 718 — 89,891 6,186 1964-2006 2021 (1) 230 CityPoint Office Waltham, MA — 13,189 49,823 24,297 13,807 73,502 — — 87,309 40,959 1992 2005 (1) 20 CityPoint Office Waltham, MA — 4,887 72,764 7,072 4,887 79,836 — — 84,723 13,031 2020 2007 (1) Sumner Square Office Washington, DC — 624 28,745 51,253 27,837 52,785 — — 80,622 32,911 1985 1999 (1) 77 CityPoint Office Waltham, MA — 13,847 60,383 1,506 14,023 61,713 — — 75,736 26,943 2008 2001 (1) 2440 West El Camino Real Office Mountain View, CA — 16,741 51,285 6,565 16,741 57,850 — — 74,591 21,469 1987/2003 2011 (1) Wisconsin Place Office Chevy Chase, MD — — 53,349 13,834 — 67,183 — — 67,183 28,960 2009 2004 (1) Reston Corporate Center Office Reston, VA — 9,135 50,857 4,489 10,148 54,333 — — 64,481 34,194 1984 1998 (1) 255 Main Street Office Cambridge, MA — 134 25,110 33,330 548 58,026 — — 58,574 43,927 1987 1997 (1) University Place Office Cambridge, MA — — 37,091 15,768 4,807 48,052 — — 52,859 37,130 1985 1998 (1) 890 Winter Street Office Waltham, MA — 13,913 28,557 8,507 13,913 37,064 — — 50,977 7,296 1999 2019 (1) Capital Gallery Office Washington, DC — 4,725 29,565 10,361 8,662 35,989 — — 44,651 23,764 1981/2006 2007 (1) North First Business Park Office San Jose, CA — 23,398 13,069 5,258 23,378 18,347 — — 41,725 17,354 1981 2007 (1) 150 Broadway Office Cambridge, MA — 850 25,042 15,749 1,323 40,318 — — 41,641 18,506 1999 1997 (1) 105 Broadway Office Cambridge, MA — 1,299 12,943 12,723 2,395 24,570 — — 26,965 16,847 1990 1997 (1) Lexington Office Park Office Lexington, MA — 998 1,426 19,924 1,263 19,470 1,615 — 22,348 17,200 1982 1997 (1) The Point Office Waltham, MA — 6,395 10,040 546 6,492 10,489 — — 16,981 2,638 2015 2007 (1) Boston Properties, Inc. Schedule 3—Real Estate and Accumulated Depreciation December 31, 2023 (dollars in thousands) Property Name Type Location Encumbrances 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 Year(s) Acquired Depreciable Lives (Years) Land Building 690 Folsom Street Office San Francisco, CA — 3,219 11,038 1,877 3,219 12,915 — — 16,134 4,280 2015 2012 (1) 33 Hayden Avenue Office Lexington, MA — 266 3,234 11,502 425 14,577 — — 15,002 9,090 1979 1997 (1) Avant Retail Office Reston, VA — 1,499 6,647 2,577 1,499 9,224 — — 10,723 3,587 2014 2010 (1) 92-100 Hayden Avenue Office Lexington, MA — 594 6,748 1,922 778 8,486 — — 9,264 7,388 1985 1997 (1) 32 Hartwell Avenue Office Lexington, MA — 168 1,943 6,403 314 8,200 — — 8,514 2,931 1968/1979/1987 1997 (1) 250 Binney Street Office Cambridge, MA — 110 4,483 3,593 273 7,913 — 8,186 7,244 1983 1997 (1) 453 Ravendale Drive Office Mountain View, CA — 5,477 1,090 1,286 5,477 2,376 — — 7,853 1,086 1977 2012 (1) 17 Hartwell Avenue Office Lexington, MA — 26 150 6,064 65 6,175 — 6,240 3,755 1968 1997 (1) The Skylyne Residential Oakland, CA — 28,962 239,077 1,792 28,962 240,869 — — 269,831 20,181 2020 N/A (1) Signature at Reston Residential Reston, VA — 27,076 190,580 3,817 27,076 194,397 — — 221,473 27,876 2018 2013 (1) Proto Kendall Square Residential Cambridge, MA — 9,243 127,248 3,336 9,245 130,582 — — 139,827 17,820 2018 2015 (1) The Lofts at Atlantic Wharf Residential Boston, MA — 3,529 54,891 2,509 3,529 57,400 — — 60,929 18,631 2011 2007 (1) Boston Marriott Cambridge Hotel Cambridge, MA — 478 37,918 32,131 1,201 68,697 629 — 70,527 53,282 1986/2017 1997 (1) Kendall Center Green Garage Garage Cambridge, MA — (2) — 35,035 7,335 103 42,267 — — 42,370 18,414 1984 2006 (1) Kendall Center Yellow Garage Garage Cambridge, MA — 1,256 15,697 1,743 1,434 17,262 — — 18,696 7,857 2006 2004 (1) 290 Binney Street Development Cambridge, MA — — — 243,099 1,054 — — 242,045 243,099 — N/A 1997 N/A 180 CityPoint Development Waltham, MA — — — 214,754 10,908 108,970 — 94,876 214,754 541 N/A 2006 N/A 300 Binney Street Development Cambridge, MA — 18,080 51,262 38,454 18,080 27,805 — 61,911 107,796 6,719 2013 2009 N/A 103 CityPoint Development Waltham, MA — — — 88,190 4,672 3,025 8,672 71,821 88,190 18 N/A 2007 N/A Reston Next Office Phase II Development Reston, VA — — — 39,201 — — — 39,201 39,201 — N/A 1998 N/A Reston Next Retail Development Reston, VA — — — 8,367 — — — 8,367 8,367 — N/A 1998 N/A 343 Madison Avenue Land New York, NY — — — 206,052 158,885 — 47,167 — 206,052 — N/A 2023 N/A 777 Harrison Street Land San Francisco, CA — 144,647 — 28,334 — 47 172,934 — 172,981 29 N/A 2020 N/A Back Bay Station Master Plan Land Boston, MA — — — 78,150 — — 78,150 — 78,150 — N/A N/A N/A 3625-3635 Peterson Way Land Santa Clara, CA — 63,206 — 5,173 — — 68,379 — 68,379 — N/A 2016 N/A Kendall Center Master Plan Land Cambridge, MA — — — 48,857 — — 48,857 — 48,857 — N/A 1997 N/A North First Master Plan Land San Jose, CA — 35,004 — 4,068 — — 39,072 — 39,072 — N/A 2007 N/A Plaza at Almaden Land San Jose, CA — — — 38,163 — — 38,163 — 38,163 — N/A 2006 N/A CityPoint South Master Plan Land Waltham, MA — — — 25,594 — — 25,594 — 25,594 — N/A N/A N/A Springfield Metro Center Land Springfield, VA — — — 19,896 — — 19,896 — 19,896 — N/A 2007 N/A Reston Gateway Master Plan Land Reston, VA — — — 13,908 — — 13,908 — 13,908 — N/A 1998 N/A Weston Quarry Land Weston, MA — — — 1,249 — — 1,249 — 1,249 — N/A 2001 N/A Broad Run Business Park Land Loudoun County, VA — — — 1,186 — — 1,186 — 1,186 — N/A 1998 N/A Reston Overlook Master Plan Land Reston, VA — — — 80 — — 80 — 80 — N/A 2000 N/A $ 4,166,379 (3) $ 5,637,035 $ 15,478,086 $ 6,306,350 $ 5,953,798 (4) $ 20,223,332 (5) $ 697,061 (6) $ 547,280 $ 27,421,471 $ 6,841,404 Note: Total Real Estate does not include Furniture, Fixtures and Equipment totaling approximately $53,716. Accumulated Depreciation does not include approximately $40,324 of accumulated depreciation related to Furniture, Fixtures and Equipment. Office type includes office, life sciences, and retail properties. The aggregate cost and accumulated depreciation for tax purposes was approximately $25.2 billion and $5.9 billion, respectively. (1) Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years. (2) This property is encumbered with the mortgage note shown at 355 Main Street. See Note 7 to the Consolidated Financial Statements. (3) Includes unamortized deferred financing costs and fair value debt adjustment totaling approximately $(33.6) million. (4) Includes Right of Use Assets - Finance Leases and Right of Use Assets - Operating Leases of approximately $378,276 and $324,298, respectively. (5) Includes Right of Use Assets - Finance Leases of approximately $23,404. (6) Includes pre-development costs. Boston Properties, Inc. Real Estate and Accumulated Depreciation December 31, 2023, 2022 and 2021 (dollars in thousands) A summary of activity for real estate and accumulated depreciation is as follows: 2023 2022 2021 Real Estate: Balance at the beginning of the year $ 25,744,214 $ 24,108,220 $ 23,303,303 Additions to/improvements of real estate 1,811,036 2,228,000 1,145,084 Assets sold/written-off (133,779) (592,006) (340,167) Balance at the end of the year $ 27,421,471 $ 25,744,214 $ 24,108,220 Accumulated Depreciation: Balance at the beginning of the year $ 6,260,992 $ 5,848,183 $ 5,501,637 Depreciation expense 714,191 646,020 623,854 Assets sold/written-off (133,779) (233,211) (277,308) Balance at the end of the year $ 6,841,404 $ 6,260,992 $ 5,848,183 Note: Real Estate and Accumulated Depreciation amounts do not include Furniture, Fixtures and Equipment. Boston Properties Limited Partnership Schedule 3—Real Estate and Accumulated Depreciation December 31, 2023 (dollars in thousands) 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 Year(s) Acquired Depreciable Lives Property Name Type Location Encumbrances Land Building 767 Fifth Avenue (the General Motors Building) Office New York, NY $ 2,288,004 $ 1,796,252 $ 1,532,654 $ 365,829 $ 1,796,252 $ 1,898,483 $ — $ — $ 3,694,735 $ 507,660 1968/2019 2013 (1) Prudential Center Office Boston, MA — 92,077 948,357 732,224 100,535 1,643,064 — 29,059 1,772,658 754,356 1965/1993/2002/2016-2017 1998/1999/2000 (1) Embarcadero Center Office San Francisco, CA — 179,697 847,410 462,102 180,419 1,308,790 — — 1,489,209 760,144 1970/1989 1998-1999 (1) 399 Park Avenue Office New York, NY — 339,200 700,358 349,238 339,200 1,049,596 — — 1,388,796 462,543 1961/2018 2002 (1) 601 Lexington Avenue Office New York, NY 989,181 241,600 494,782 508,526 279,281 965,627 — — 1,244,908 360,656 1977/1997/2021 2001 (1) Salesforce Tower Office San Francisco, CA — 200,349 946,205 7,623 200,349 953,828 — — 1,154,177 159,274 2018 2013 (1) 200 Clarendon Street and Garage Office Boston, MA — 219,543 667,884 251,372 250,910 887,889 — — 1,138,799 338,529 1976 2010 (1) 250 West 55th Street Office New York, NY — 285,263 603,167 52,917 285,263 656,084 — — 941,347 198,081 2014 2007 (1) 100 Federal Street Office Boston, MA — 131,067 435,954 127,199 131,067 563,153 — — 694,220 172,079 1971-1975/2017 2012 (1) Madison Centre Office Seattle, WA — 104,641 564,336 4,082 104,641 568,418 673,059 35,516 2017 2022 (1) Times Square Tower Office New York, NY — 165,413 380,438 102,302 159,694 488,459 — — 648,153 244,067 2004 2000 (1) Carnegie Center Office Princeton, NJ — 142,666 316,856 162,582 90,501 472,803 58,800 — 622,104 262,096 1983-2016 1998/1999/2000/2007/2014/2017/2019 (1) Santa Monica Business Park Office Los Angeles, CA 295,649 46,360 410,421 164,229 210,471 410,535 4 — 621,010 865 1976-1980 2023 (1) 125 Broadway Office Cambridge, MA — 126,364 433,662 4,000 126,364 437,662 — — 564,026 20,717 2000 2022 (1) Reston Next Office Reston, VA — 35,549 525,277 — 2,901 557,925 — — 560,826 32,504 2022 1998 (1) Atlantic Wharf Office Boston, MA — 63,988 454,537 39,399 63,988 493,936 — — 557,924 180,686 2011 2007 (1) 2100 Pennsylvania Avenue Office Washington, DC — 185,203 324,206 — 185,203 324,206 — — 509,409 20,768 2023 N/A (1) Fountain Square Office Reston, VA — 56,853 306,298 49,874 56,853 356,172 — — 413,025 111,481 1986-1990 2012 (1) 599 Lexington Avenue Office New York, NY — 81,040 100,507 231,417 81,040 331,924 — — 412,964 188,193 1986 1997 (1) 510 Madison Avenue Office New York, NY — 103,000 253,665 33,100 103,000 286,765 — — 389,765 104,052 2012 2010 (1) 325 Main Street Office Cambridge, MA — (2) 21,596 312,492 30,740 21,403 343,425 — — 364,828 14,833 2022 1997 (1) 680 Folsom Street Office San Francisco, CA — 72,545 219,766 8,026 72,545 227,792 — — 300,337 80,964 2014 2012 (1) 145 Broadway Office Cambridge, MA — 121 273,013 26,156 23,164 276,126 — — 299,290 35,390 2019 1997 (1) 2200 Pennsylvania Avenue Office Washington, DC — — 183,541 114,090 102,979 194,652 — — 297,631 77,357 2011 2008 (1) South of Market and Democracy Tower Office Reston, VA — 13,603 237,479 30,616 13,603 268,095 — — 281,698 108,875 2008-2009 2003 (1) Bay Colony Corporate Center Office Waltham, MA — 18,789 148,451 96,639 18,789 240,416 4,674 — 263,879 113,123 1985-1989 2011 (1) 535 Mission Street Office San Francisco, CA — 40,933 148,378 4,629 40,934 153,006 — — 193,940 46,615 2015 2013 (1) Mountain View Research Park Office Mountain View, CA — 95,066 68,373 21,069 95,066 89,442 — — 184,508 33,095 1977-1981/2007-2013 2013 (1) Reservoir Place Office Waltham, MA — 18,605 104,124 52,085 19,089 153,898 1,827 — 174,814 89,426 1955/1987/2017 1997/1998 (1) 140 Kendrick Street Office Needham, MA — 18,095 66,905 67,871 18,095 134,776 — — 152,871 45,233 2000 2004 (1) 880 Winter Street Office Waltham, MA — 15,597 37,255 95,265 15,597 132,520 — — 148,117 10,056 1998/2022 2019 (1) Boston Properties Limited Partnership Schedule 3—Real Estate and Accumulated Depreciation December 31, 2023 (dollars in thousands) 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 Year(s) Acquired Depreciable Lives Property Name Type Location Encumbrances Land Building 1330 Connecticut Avenue Office Washington, DC — 25,982 82,311 35,311 25,982 117,622 — — 143,604 51,767 1984/2018 2004 (1) One Freedom Square Office Reston, VA — 9,929 84,504 43,348 9,883 127,898 — — 137,781 66,495 2000 2003 (1) Kingstowne Towne Center Office Alexandria, VA — 18,021 109,038 4,501 18,021 113,539 — — 131,560 54,432 2003-2006 2007 (1) Two Freedom Square Office Reston, VA — 13,930 77,739 38,856 13,866 116,659 — — 130,525 42,556 2001 2003 (1) Shady Grove Innovation District Office Rockville, MD — 52,030 64,212 10,676 26,834 34,954 65,130 — 126,918 4,701 1968-1985 2021 (1) One and Two Reston Overlook Office Reston, VA — 16,456 66,192 40,806 15,074 108,380 — — 123,454 60,074 1999 2000 (1) Weston Corporate Center Office Weston, MA — 25,753 92,312 1,038 25,854 93,249 — — 119,103 41,485 2010 2001 (1) 355 Main Street Office Cambridge, MA 593,545 18,863 53,346 41,474 21,098 92,585 — — 113,683 36,858 1981/1996/2013 2006 (1) 17Fifty Presidents Street Office Reston, VA — — 113,362 162 — 113,524 — — 113,524 16,624 2020 2013 (1) 200 West Street Office Waltham, MA — 16,148 24,983 68,538 16,148 93,164 357 — 109,669 27,290 1999/2021 1997 (1) Discovery Square Office Reston, VA — 11,198 71,782 16,199 11,146 88,033 — — 99,179 55,135 2001 2003 (1) 10 CityPoint Office Waltham, MA — 1,953 85,752 7,410 2,127 92,988 — — 95,115 24,003 2016 1997 (1) 90 Broadway Office Cambridge, MA — (2) 19,104 52,078 22,563 20,741 73,004 — — 93,745 31,484 1983/1998/2013 2006 (1) 153 & 211 Second Avenue Office Waltham, MA — 33,233 55,940 718 33,233 55,940 718 — 89,891 6,186 1964-2006 2021 (1) Waltham Weston Corporate Center Office Waltham, MA — 10,385 60,694 17,718 10,350 78,447 — — 88,797 44,588 2003 1999 (1) 230 CityPoint Office Waltham, MA — 13,189 49,823 22,680 13,403 72,289 — — 85,692 40,413 1992 2005 (1) 20 CityPoint Office Waltham, MA — 4,887 72,764 7,072 4,887 79,836 — — 84,723 13,031 2020 2007 (1) Sumner Square Office Washington, DC — 624 28,745 49,173 27,317 51,225 — — 78,542 32,209 1985 1999 (1) 77 CityPoint Office Waltham, MA — 13,847 60,383 1,401 13,997 61,634 — — 75,631 26,911 2008 2001 (1) 2440 West El Camino Real Office Mountain View, CA — 16,741 51,285 6,565 16,741 57,850 — — 74,591 21,469 1987/2003 2011 (1) Wisconsin Place Office Chevy Chase, MD — — 53,349 13,834 — 67,183 — — 67,183 28,960 2009 2004 (1) Reston Corporate Center Office Reston, VA — 9,135 50,857 1,878 9,496 52,374 — — 61,870 33,309 1984 1998 (1) 255 Main Street Office Cambridge, MA — 134 25,110 31,674 134 56,784 — — 56,918 43,368 1987 1997 (1) University Place Office Cambridge, MA — — 37,091 14,318 4,807 46,602 — — 51,409 36,037 1985 1998 (1) 890 Winter Street Office Waltham, MA — 13,913 28,557 8,507 13,913 37,064 — — 50,977 7,296 1999 2019 (1) North First Business Park Office San Jose, CA — 23,398 13,069 5,235 23,372 18,330 — — 41,702 17,347 1981 2007 (1) Capital Gallery Office Washington, DC — 4,725 29,565 5,698 6,128 33,860 — — 39,988 22,801 1981/2006 2007 (1) 150 Broadway Office Cambridge, MA — 850 25,042 13,744 822 38,814 — — 39,636 17,823 1999 1997 (1) 105 Broadway Office Cambridge, MA — 1,299 12,943 10,617 1,868 22,991 — — 24,859 16,133 1990 1997 (1) Lexington Office Park Office Lexington, MA — 998 1,426 19,160 1,072 18,897 1,615 — 21,584 16,945 1982 1997 (1) The Point Office Waltham, MA — 6,395 10,040 546 6,492 10,489 — — 16,981 2,638 2015 2007 (1) 690 Folsom Street Office San Francisco, CA — 3,219 11,038 1,877 3,219 12,915 — — 16,134 4,280 2015 2012 (1) 33 Hayden Avenue Office Lexington, MA — 266 3,234 10,865 266 14,099 — — 14,365 8,873 1979 1997 (1) Avant Retail Office Reston, VA — 1,499 6,647 2,577 1,499 9,224 — — 10,723 3,587 2014 2010 (1) 92-100 Hayden Avenue Office Lexington, MA — 594 6,748 1,193 595 7,940 — — 8,535 7,140 1985 1997 (1) Boston Properties Limited Partnership Schedule 3—Real Estate and Accumulated Depreciation December 31, 2023 (dollars in thousands) 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 Year(s) Acquired Depreciable Lives Property Name Type Location Encumbrances Land Building 32 Hartwell Avenue Office Lexington, MA — 168 1,943 5,817 168 7,760 — — 7,928 2,731 1968/1979/1987 1997 (1) 453 Ravendale Drive Office Mountain View, CA — 5,477 1,090 1,286 5,477 2,376 — — 7,853 1,086 1977 2012 (1) 250 Binney Street Office Cambridge, MA — 110 4,483 2,939 110 7,422 — 7,532 7,026 1983 1997 (1) 17 Hartwell Avenue Office Lexington, MA — 26 150 5,907 26 6,057 — — 6,083 3,701 1968 1997 (1) The Skylyne Residential Oakland, CA — 28,962 239,077 1,792 28,962 240,869 — — 269,831 20,181 2020 N/A (1) Signature at Reston Residential Reston, VA — 27,076 190,580 3,817 27,076 194,397 — — 221,473 27,876 2018 2013 (1) Proto Kendall Square Residential Cambridge, MA — 9,243 127,248 3,336 9,245 130,582 — — 139,827 17,820 2018 2015 (1) The Lofts at Atlantic Wharf Residential Boston, MA — 3,529 54,891 2,509 3,529 57,400 — — 60,929 18,631 2011 2007 (1) Boston Marriott Cambridge Hotel Cambridge, MA — 478 37,918 29,240 478 66,529 629 — 67,636 52,302 1986/2017 1997 (1) Kendall Center Green Garage Garage Cambridge, MA — (2) — 35,035 6,921 — 41,956 — — 41,956 18,275 1984 2006 (1) Kendall Center Yellow Garage Garage Cambridge, MA — 1,256 15,697 1,031 1,256 16,728 — — 17,984 7,619 2006 2004 (1) 290 Binney Street Development Cambridge, MA — — — 242,683 638 — — 242,045 242,683 — N/A 1997 N/A 180 CityPoint Development Waltham, MA — — — 214,754 10,908 108,970 — 94,876 214,754 541 N/A 2006 N/A 300 Binney Street Development Cambridge, MA — 18,080 51,262 38,454 18,080 27,805 — 61,911 107,796 6,719 2013 2009 N/A 103 CityPoint Development Waltham, MA — — — 88,188 4,670 3,025 8,672 71,821 88,188 18 N/A 2007 N/A Reston Next Office Phase II Development Reston, VA — — — 39,201 — — — 39,201 39,201 — N/A 1998 N/A Reston Next Retail Development Reston, VA — — — 8,367 — — — 8,367 8,367 — N/A 1998 N/A 343 Madison Avenue Land New York, NY — — — 206,052 158,885 — 47,167 — 206,052 — N/A 2023 N/A 777 Harrison Street Land San Francisco, CA — 144,647 — 28,334 — 47 172,934 — 172,981 29 N/A 2020 N/A Back Bay Station Master Plan Land Boston, MA — — — 78,150 — — 78,150 — 78,150 — N/A N/A N/A 3625-3635 Peterson Way Land Santa Clara, CA — 63,206 — 5,173 — — 68,379 — 68,379 — N/A 2016 N/A Kendall Center Master Plan Land Cambridge, MA — — — 48,857 — — 48,857 — 48,857 — N/A 1997 N/A North First Master Plan Land San Jose, CA — 35,004 — 4,068 — — 39,072 — 39,072 — N/A 2007 N/A Plaza at Almaden Land San Jose, CA — — — 38,163 — — 38,163 — 38,163 — N/A 2006 N/A CityPoint South Master Plan Land Waltham, MA — — — 25,594 — — 25,594 — 25,594 — N/A N/A N/A Springfield Metro Center Land Springfield, VA — — — 19,896 — — 19,896 — 19,896 — N/A 2007 N/A Reston Gateway Master Plan Land Reston, VA — — — 13,908 — — 13,908 — 13,908 — N/A 1998 N/A Weston Quarry Land Weston, MA — — — 1,249 — — 1,249 — 1,249 — N/A 2001 N/A Broad Run Business Park Land Loudoun County, VA — — — 1,186 — — 1,186 — 1,186 — N/A 1998 N/A Reston Overlook Master Plan Land Reston, VA — — — 80 — — 80 — 80 — N/A 2000 N/A $ 4,166,379 (3) $ 5,637,035 $ 15,478,086 $ 5,940,085 $ 5,859,089 (4) $ 19,951,776 (5) $ 697,061 (6) $ 547,280 $ 27,055,206 $ 6,718,037 Note: Total Real Estate does not include Furniture, Fixtures and Equipment totaling approximately $53,716. Accumulated Depreciation does not include approximately $40,324 of accumulated depreciation related to Furniture, Fixtures and Equipment. Office type includes office, life sciences, and retail properties. The aggregate cost and accumulated depreciation for tax purposes was approximately $28.2 billion and $6.6 billion, respectively. (1) Depreciation of the buildings and improvements are calculated over lives ranging from the life of the lease to 40 years. (2) This property is encumbered with the mortgage note shown at 355 Main Street. See Note 7 to the Consolidated Financial Statements. (3) Includes unamortized deferred financing costs and fair value debt adjustment totaling approximately $(33.6) million. (4) Includes Right of Use Assets - Finance Leases and Right of Use Assets - Operating Leases of approximately $378,276 and $324,298, respectively. (5) Includes Right of Use Assets - Finance Leases of approximately $23,404. (6) Includes pre-development costs. Boston Properties Limited Partnership Real Estate and Accumulated Depreciation December 31, 2023, 2022 and 2021 (dollars in thousands) A summary of activity for real estate and accumulated depreciation is as follows: 2023 2022 2021 Real Estate: Balance at the beginning of the year $ 25,376,700 $ 23,734,833 $ 22,926,494 Additions to/improvements of real estate 1,811,036 2,228,000 1,145,084 Assets sold/written-off (132,530) (586,133) (336,745) Balance at the end of the year $ 27,055,206 $ 25,376,700 $ 23,734,833 Accumulated Depreciation: Balance at the beginning of the year $ 6,143,384 $ 5,736,240 $ 5,396,111 Depreciation expense 707,183 638,538 615,553 Assets sold/written-off (132,530) (231,394) (275,424) Balance at the end of the year $ 6,718,037 $ 6,143,384 $ 5,736,240 Note: Real Estate and Accumulated Depreciation amounts do not include Furniture, Fixtures and Equipment. |
