Secured and unsecured senior debt (Tables)

6 Months Ended

Jun. 30, 2024

Schedule of maturities of secured and unsecured debt

The following table summarizes our outstanding indebtedness and respective principal payments remaining as of June 30, 2024 (dollars in thousands):


	Stated Rate	Interest Rate(1)		Maturity Date(2)		Principal Payments Remaining for the Periods Ending December 31,							Unamortized (Deferred Financing Cost), (Discount)/ Premium
Debt	Stated Rate	Interest Rate(1)		Maturity Date(2)		2024	2025	2026	2027	2028	Thereafter	Principal	Unamortized (Deferred Financing Cost), (Discount)/ Premium	Total
Secured notes payable
Greater Boston(3)	SOFR+2.70%	8.14%		11/19/26		$—	$—	$134,648	$—	$—	$—	$134,648	$(325)	$134,323
San Francisco Bay Area	6.50%	6.50		7/1/36		32	34	36	38	41	438	619	—	619
Secured debt weighted-average interest rate/ subtotal		8.13				32	34	134,684	38	41	438	135,267	(325)	134,942

Unsecured senior line of credit and commercial paper program(4)	(4)	5.57	(4)	1/22/28	(4)	—	—	—	—	200,000	—	200,000	(448)	199,552
Unsecured senior notes payable	3.45%	3.62		4/30/25		—	600,000	—	—	—	—	600,000	(739)	599,261
Unsecured senior notes payable	4.30%	4.50		1/15/26		—	—	300,000	—	—	—	300,000	(778)	299,222
Unsecured senior notes payable	3.80%	3.96		4/15/26		—	—	350,000	—	—	—	350,000	(899)	349,101
Unsecured senior notes payable	3.95%	4.13		1/15/27		—	—	—	350,000	—	—	350,000	(1,321)	348,679
Unsecured senior notes payable	3.95%	4.07		1/15/28		—	—	—	—	425,000	—	425,000	(1,523)	423,477
Unsecured senior notes payable	4.50%	4.60		7/30/29		—	—	—	—	—	300,000	300,000	(1,138)	298,862
Unsecured senior notes payable	2.75%	2.87		12/15/29		—	—	—	—	—	400,000	400,000	(2,269)	397,731
Unsecured senior notes payable	4.70%	4.81		7/1/30		—	—	—	—	—	450,000	450,000	(2,241)	447,759
Unsecured senior notes payable	4.90%	5.05		12/15/30		—	—	—	—	—	700,000	700,000	(5,121)	694,879
Unsecured senior notes payable	3.375%	3.48		8/15/31		—	—	—	—	—	750,000	750,000	(4,669)	745,331
Unsecured senior notes payable	2.00%	2.12		5/18/32		—	—	—	—	—	900,000	900,000	(7,428)	892,572
Unsecured senior notes payable	1.875%	1.97		2/1/33		—	—	—	—	—	1,000,000	1,000,000	(7,543)	992,457
Unsecured senior notes payable	2.95%	3.07		3/15/34		—	—	—	—	—	800,000	800,000	(7,613)	792,387
Unsecured senior notes payable	4.75%	4.88		4/15/35		—	—	—	—	—	500,000	500,000	(5,185)	494,815
Unsecured senior notes payable	5.25%	5.38		5/15/36		—	—	—	—	—	400,000	400,000	(4,280)	395,720
Unsecured senior notes payable	4.85%	4.93		4/15/49		—	—	—	—	—	300,000	300,000	(2,929)	297,071
Unsecured senior notes payable	4.00%	3.91		2/1/50		—	—	—	—	—	700,000	700,000	10,049	710,049
Unsecured senior notes payable	3.00%	3.08		5/18/51		—	—	—	—	—	850,000	850,000	(11,417)	838,583
Unsecured senior notes payable	3.55%	3.63		3/15/52		—	—	—	—	—	1,000,000	1,000,000	(13,892)	986,108
Unsecured senior notes payable	5.15%	5.26		4/15/53		—	—	—	—	—	500,000	500,000	(7,702)	492,298
Unsecured senior notes payable	5.625%	5.71		5/15/54		—	—	—	—	—	600,000	600,000	(6,801)	593,199
Unsecured debt weighted-average interest rate/ subtotal		3.84				—	600,000	650,000	350,000	625,000	10,150,000	12,375,000	(85,887)	12,289,113
Weighted-average interest rate/total		3.89%				$32	$600,034	$784,684	$350,038	$625,041	$10,150,438	$12,510,267	$(86,212)	$12,424,055

(1)Represents the weighted-average interest rate as of the end of the applicable period, including amortization of loan fees, amortization of debt premiums (discounts), and other bank fees.

(2)Reflects any extension options that we control.

(3)Represents a secured construction loan held by our consolidated real estate joint venture for 99 Coolidge Avenue, of which we own a 75.0% interest. As of June 30, 2024, this joint venture has $60.7 million available under existing lender

commitments. The interest rate shall be reduced from SOFR+2.70% to SOFR+2.10% over time upon the completion of certain leasing, construction, and financial covenant milestones.

(4)Refer to “$5.0 billion unsecured senior line of credit” and “$2.5 billion commercial paper program” on the following page. In July 2024, we executed an agreement with the lender group to amend and restate our unsecured senior line of

credit to, among other changes, extend the maturity date from January 22, 2028 to January 22, 2030, including extension options that we control. We expect that the amendment and restatement will become effective in September 2024

upon the satisfaction of certain conditions.

Summary of secured and unsecured debt

The following table summarizes our secured and unsecured senior debt and amounts outstanding under our unsecured senior

line of credit and commercial paper program as of June 30, 2024 (dollars in thousands):


	Fixed-Rate Debt	Variable-Rate Debt				Weighted-Average
						Interest		Remaining Term (in years)
			Total		Percentage	Rate(1)		Remaining Term (in years)
Secured notes payable	$619	$134,323	$134,942		1.1%	8.13%		2.4
Unsecured senior notes payable	12,089,561	—	12,089,561		97.3	3.81		13.3
Unsecured senior line of credit and commercial paper program	—	199,552	199,552	(2)	1.6	5.57	(2)	3.6	(3)
Total/weighted average	$12,090,180	$333,875	$12,424,055		100.0%	3.89%		13.0	(3)
Percentage of total debt	97.3%	2.7%	100%

(1)Represents the weighted-average interest rate as of the end of the applicable period, including expense/income related to the amortization of loan fees, amortization of

debt premiums (discounts), and other bank fees.

(2)As of June 30, 2024, we had no outstanding balance on our unsecured senior line of credit and $199.6 million of commercial paper notes outstanding with a weighted-

average interest rate of 5.57%.

(3)We calculate the weighted-average remaining term of our commercial paper notes by using the maturity date of our unsecured senior line of credit. Using the maturity

date of our outstanding commercial paper notes, the consolidated weighted-average maturity of our debt is 13.0 years. The commercial paper notes sold during the six

months ended June 30, 2024 were issued at a weighted-average yield to maturity of 5.59% and had a weighted-average maturity term of 16 days.

Schedule of Interest Incurred

The following table summarizes interest expense for the three and six months ended June 30, 2024 and 2023 (in thousands):


	Three Months Ended June 30,		Six Months Ended June 30,
	2024	2023	2024	2023
Interest incurred	$126,828	$108,746	$249,508	$209,570
Capitalized interest	(81,039)	(91,674)	(162,879)	(178,744)
Interest expense	$45,789	$17,072	$86,629	$30,826