Image courtesy of KS Partners

An 11-story office building in Downtown Crossing would be reborn as rental housing under plans submitted by a developer active in Boston’s residential conversion program.

KS Partners plans 90 apartments, including 42 studios, at the 15 Court Square property that it acquired in 2019 for $29 million.

The developer hired Boston-based Balance Architects to design the $27.9 million conversion, breaking up the 7,269-square-foot floor plates into eight apartments apiece. The project would include a 17 percent income-restricted component.

No parking is proposed or required, according to a small project review submitted to the Boston Planning Department.

Boston’s downtown office to residential conversion program has attracted applications that would create 546 housing units. The program reduces property taxes by 75 percent over a 29-year period.

According to an application for the tax abatement submitted in June, KS Partners estimates market-rate rents at $1,500 to $4,800. At the time, the building had 14 commercial tenants, including eight with leases expiring after October 2025. Tenants will be offered the chance to relocate to other KS Partners-owned properties in the downtown area, according to the filing.

KS Partners also is pursuing conversion projects at 95 Devonshire St. and 258 and 262 Washington St.