FRANKLIN STREET PROPERTIES CORP /MA/ 10-K

Item 2. Properties ​ Set forth below is information regarding our properties as of December 31, 2025: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Approx. ​ Percent ​ Approx. ​ ​ ​ ​ ​ ​ Date of ​ Square ​ Leased as ​ Number ​ ​ Property Location ​ Purchase (1) ​ Feet ​ of 12/31/25 ​ of Tenants ​ Major Tenants (2) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Office ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 16285 Park Ten Place 6/27/02 157,609 86.8 % 10 Blade Energy Partners, Ltd. ​ Houston, TX 77084 ​ ​ ​ ​ ​ ​ ​ ​ ​ Baytex Energy USA, Inc. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Edge Engineering & Science, LLC ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Liberty Lift Solutions, LLC ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 15601 Dallas Parkway 9/30/02 289,333 67.7 % 11 Cyxtera Management Inc. ​ Addison, TX 75001 ​ ​ ​ ​ ​ ​ ​ ​ ​ WDT Acquisition Corporation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CarOffer, LLC ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1293 Eldridge Parkway 1/16/04 248,399 100.0 % 1 CITGO Petroleum Corporation ​ Houston, TX 77077 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 6550 & 6560 Greenwood Plaza Englewood, CO 80111 2/24/05 196,236 65.0 % 2 Kaiser Foundation Health Plan, Inc. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 16290 Katy Freeway 9/28/05 156,746 76.3 % 5 Olin Corporation ​ Houston, TX 77094 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5055 & 5057 Keller Springs Rd. 2/24/06 217,841 66.9 % 19 See Footnote 3 ​ Addison, TX 75001 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 121 South Eighth Street Minneapolis, MN 55402 6/29/10 297,744 80.4 % 34 Schwegman, Lundberg & Woessner ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 801 Marquette Ave. South ​ 6/29/10 129,691 91.8 % 3 ​ Workbox Marquette MN, LLC ​ Minneapolis, MN 55402 ​ ​ ​ ​ ​ ​ ​ ​ ​ Greater Minneapolis Convention & Visitor Association ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Deluxe Corporation ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 5100 & 5160 Tennyson Parkway Plano, TX 75024 3/10/11 209,562 60.9 % 6 ARK-LA-TEX Financial Services, LLC ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Moss, Luse & Womble, LLC ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 10370 & 10350 Richmond Ave. 11/1/12 629,025 66.2 % 45 See Footnote 3 ​ Houston, TX 77042 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1999 Broadway 5/22/13 682,639 50.7 % 25 United States Government ​ Denver, CO 80202 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 1001 17th Street 8/28/13 650,607 76.4 % 18 Permian Resources Operating, LLC ​ Denver CO, 80202 ​ ​ ​ ​ ​ ​ ​ ​ ​ Hall and Evans, LLC ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ping Identity Corp. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 18 Table of Contents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Approx. ​ Percent ​ Approx. ​ ​ ​ ​ ​ ​ Date of ​ Square ​ Leased as ​ Number ​ ​ Property Location ​ Purchase (1) ​ Feet ​ of 12/31/25 ​ of Tenants ​ Major Tenants (2) 45 South Seventh Street 6/6/16 330,096 51.0 % 15 PwC US Group ​ Minneapolis, MN 55402 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 600 17th Street 12/1/16 612,135 69.1 % 25 EOG Resources, Inc. ​ Denver, CO 80202 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Owned Portfolio ​ ​ ​ 4,807,663 ​ 68.9 % ​ ​ ​ ​ ​ (1) Date of purchase or merged entity date of purchase. (2) Major tenants that occupy 10% or more of the space in an individual property. (3) No tenant occupies more than 10% of the space. ​ All of the properties listed above are owned, directly or indirectly, by us. None of our owned properties are subject to any mortgage loans as of December 31, 2025. We have no other material undeveloped or unimproved properties, or proposed programs for material renovation or development of any of our properties in 2026. We believe that our properties are adequately covered by insurance as of December 31, 2025. ​ ​ 19 Table of Contents The information presented below provides the weighted average GAAP rent per square foot for the year ended December 31, 2025 for our owned properties and weighted occupancy square feet and percentages. GAAP rent includes the impact of tenant concessions and reimbursements. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Occupied ​ Weighted ​ ​ ​ ​ ​ ​ Year Built ​ ​ ​ Weighted ​ Percentage as of ​ Average ​ ​ ​ ​ ​ ​ or ​ Net Rentable ​ Occupied ​ December 31, ​ Rent per Occupied Property Name ​ City ​ State ​ Renovated ​ Square Feet ​ Sq. Ft. ​ 2025 (a) ​ Square Feet (b) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 121 South 8th Street ​ Minneapolis ​ MN ​ 1974 ​ 297,744 ​ 228,697 ​ 76.8 % $ 22.96 ​ 801 Marquette Ave ​ Minneapolis ​ MN ​ 1923/2017 ​ 129,691 ​ 119,108 ​ 91.8 % ​ 25.97 ​ Plaza Seven ​ Minneapolis ​ MN ​ 1987 ​ 330,096 ​ 167,029 ​ 50.6 % 29.30 ​ Midwest Total ​ ​ ​ ​ ​ ​ ​ 757,531 ​ 514,834 ​ 68.0 % 25.71 ​ Park Ten ​ Houston ​ TX ​ 1999 ​ 157,609 ​ 132,518 ​ 84.1 % 27.45 ​ Addison Circle ​ Addison ​ TX ​ 1999 ​ 289,333 ​ 197,267 ​ 68.2 % 35.43 ​ Eldridge Green ​ Houston ​ TX ​ 1999 ​ 248,399 ​ 248,399 100.0 % ​ 27.93 ​ Park Ten Phase II ​ Houston ​ TX ​ 2006 ​ 156,746 ​ 111,556 71.2 % ​ 29.26 ​ Liberty Plaza ​ Addison ​ TX ​ 1985 ​ 217,841 ​ 147,980 67.9 % ​ 26.43 ​ Legacy Tennyson Center ​ Plano ​ TX ​ 1999/2008 ​ 209,562 ​ 109,978 52.5 % ​ 32.13 ​ Westchase I & II ​ Houston ​ TX ​ 1983/2008 ​ 629,025 ​ 396,789 63.1 % ​ 26.44 ​ South Total ​ ​ ​ ​ ​ ​ ​ 1,908,515 ​ 1,344,487 70.4 % ​ 28.83 ​ 1999 Broadway ​ Denver ​ CO ​ 1986 ​ 682,639 ​ 333,060 48.8 % ​ 34.74 ​ 1001 17th Street ​ Denver ​ CO ​ 1977/2006 ​ 650,607 ​ 479,562 73.7 % ​ 36.64 ​ 600 17th Street ​ Denver ​ CO ​ 1982 ​ 612,135 ​ 439,084 71.7 % ​ 33.85 ​ Greenwood Plaza ​ Englewood ​ CO ​ 2000 ​ 196,236 ​ 127,573 65.0 % ​ 30.96 ​ West Total ​ ​ ​ ​ ​ ​ ​ 2,141,617 ​ 1,379,279 64.4 % ​ 34.77 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Owned Properties ​ ​ ​ ​ ​ ​ ​ 4,807,663 ​ 3,238,600 ​ 67.4 % $ 30.86 ​ (a) Based on weighted occupied square feet for the year ended December 31, 2025, including month-to-month tenants, divided by the property’s net rentable square footage. (b) Represents annualized GAAP rental revenue for the year ended December 31, 2025 per weighted occupied square foot. ​ 20 Table of Contents The information presented below is a lease expiration table for ten years and thereafter, stating (i) the number of tenants whose leases will expire, (ii) the total area in square feet covered by such leases, (iii) the annual rental represented by such leases in dollars and by square feet, and (iv) the percentage of gross annual rental represented by such leases. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Rentable ​ ​ ​ ​ Annualized ​ Percentage ​ ​ ​ ​ ​ Number of ​ Square ​ ​ ​ ​ Rent ​ of Total ​ ​ ​ Year of ​ Leases ​ Footage ​ Annualized ​ Per Square ​ Annualized ​ ​ ​ Lease ​ Expiring ​ Subject to ​ Rent Under ​ Foot Under ​ Rent Under ​ ​ ​ Expiration ​ Within the ​ Expiring ​ Expiring ​ Expiring ​ Expiring ​ Cumulative ​ December 31, ​ ​ ​ Year (a) ​ ​ ​ Leases ​ ​ ​ Leases (b) ​ ​ ​ Leases ​ ​ ​ Leases ​ ​ ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2026 ​ 34 (c) 365,916 ​ $ 12,569,114 ​ $ 34.35 ​ 12.0 % 12.0 % 2027 ​ 35 ​ 500,108 ​ ​ 18,191,656 ​ ​ 36.38 ​ 17.4 % 29.4 % 2028 ​ 25 ​ 242,046 ​ ​ 7,957,724 ​ ​ 32.88 ​ 7.6 % 37.0 % 2029 ​ 40 ​ 561,561 ​ ​ 18,213,553 ​ ​ 32.43 ​ 17.4 % 54.4 % 2030 ​ 20 ​ 268,950 ​ ​ 8,662,656 ​ ​ 32.21 ​ 8.2 % 62.6 % 2031 ​ 21 ​ 346,964 ​ ​ 11,496,581 ​ ​ 33.13 ​ 11.0 % 73.6 % 2032 ​ 8 ​ 77,324 ​ ​ 1,733,552 ​ ​ 22.42 ​ 1.7 % 75.3 % 2033 ​ 10 ​ 383,978 ​ ​ 11,685,696 ​ ​ 30.43 ​ 11.2 % 86.5 % 2034 ​ 8 ​ 90,757 ​ ​ 1,724,368 ​ ​ 19.00 ​ 1.6 % 88.1 % 2035 ​ 7 ​ 173,219 ​ ​ 5,667,946 ​ ​ 32.72 ​ 5.4 % 93.5 % 2036 and thereafter ​ 22 ​ 300,199 (d) ​ 6,827,766 ​ ​ 22.74 ​ 6.5 % 100.0 % Leased total ​ 230 ​ 3,311,022 ​ $ 104,730,612 ​ $ 31.63 ​ 100.0 % ​ ​ Vacancies as of 12/31/25 ​ ​ ​ 1,496,641 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Total Portfolio Square Footage ​ ​ ​ 4,807,663 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (a) The number of leases approximates the number of tenants. Tenants with lease maturities in different years are included in annual totals for each lease. Tenants may have multiple leases in the same year. (b) Annualized rent represents the monthly rent charged, including tenant reimbursements, for each lease in effect at December 31, 2025 multiplied by 12. Tenant reimbursements generally include payment of real estate taxes, operating expenses and common area maintenance and utility charges. (c) Includes 2 leases that are month-to-month. (d) Includes 52,202 square feet that are non-revenue producing building amenities. ​ ​