Two developers are teaming up to bring a $20 million condominium project to downtown Salem, replacing a Brutalist-style courthouse with 61 units of market-rate and affordable housing.

The joint venture between Cambridge-based Urban Spaces and development firm Diamond Sinacori has begun work on the BRIX project, designed by Newton-based Tise Design Assoc. and built by Salem-based Groom Construction. The 110,000-square-foot complex at 65 Washington St. will contain units ranging from 800 to 1,700 square feet, with prices starting in the mid-$400,000 range, developers said.

Amenities include a roof terrace, club room, pet spa, fitness studio and 3,000 square feet of retail or restaurant space. The property will be served by a two-level, 88-space parking garage.

Developers acquired the former Salem District Courthouse property from the Salem Redevelopment Authority in November 2018. The unit mix will include eight one-bedroom, 44 two-bedroom and nine three-bedroom units.

Following demolition of the former courthouse building, a wood-framed building above a steel-and-concrete podium will be constructed. Charlesgate Realty Group and Salem-based Merry Fox Realty are marketing the units.

Salem Five Bank provided $20 million in debt financing.