Holt Hall, containing 50,000 s.f., was built as the Maine Eye and Ear Infirmary in Portland, ME in 1886. It is an architecturally significant building, designed by Calvert Stevens, a prominent Portland architect. It is listed on the National Register of Historic Places. By the mid-1990’s, the building had been vacant for nearly 15 years, with significant internal water damage due to a leaking roof.

In 1998, in a joint venture with John Moriarty & Associates (JMA), Concord Square and JMA completed an historic re-development of the building into 36 high-end rental apartments on the upper floors, and commercial space on the first floor.

Financing for the project included a HUD 221 (d) (4) loan and Federal Historic tax Credits equal to 20% of the renovation costs. Concord Square secured required zoning variances and other local approvals, a 20 year Tax Increment Financing Agreement with the City, a long-term lease with Maine Medical Center for the entire first floor of the building, and two leases for cell phone antennas on the roof.

Ted Carman sold his interest in the property in 2025. For the prior 25 years he provided supervisory management services to the project, which was managed by Dirigo Management Company from Portland. The building operated at over 97% collections since it opened in 1999.