18 Congress Street

Single-tenant Class A office condominium (2,424 SF) in downtown Portsmouth’s iconic Market Square. Suite 207 is located on the second floor of a premier mixed-use building developed in 2006, with one deeded garage parking space. Leased to O’Brien Energy Resources Corporation under a 10-year Absolute Net lease at $127,308/year (effective April 2026), with 3% annual rent escalations compounding through 2034. Investment highlights 6.5% cap rate with built-in 3% annual rent growth Absolute Net lease Premier Market Square location — walkable to 100+ restaurants, retailers, and waterfront Class A building (2006) — elevator, structured parking, professional lobby Deeded garage parking space included Condo association manages all building operations