BOULDER — Boulder Housing Partners plans to redevelop a 4.35-acre site in Boulder to create a 115-unit affordable-housing apartment complex.

The site at 3300 Penrose Place is the headquarters for the Geological Society of America, which is adjacent to Foothills Parkway and 34th Street. The GSA will lease back the facility for up to two years and in the meantime is looking for another location.

The GSA headquarters is in an architecturally notable building that will be retained in the redevelopment, BHP said in a press statement. 

“This is the kind of opportunity we especially enjoy being a part of for our community,” Jeremy Durham, executive director of BHP, said in the statement. “We’ll build these 115 homes to be affordable, sustainable, and beautifully designed for residents, all while giving an existing community asset new life as the focal point of the development’s design.”

BHP said that it plans to renovate and repurpose an existing building at the former Mount Calvary Lutheran Church, 3485 Stanford Court, along with construction of new affordable homes. 

The homes at Penrose Place will be permanently affordable, according to the plan, and include a mix of one, two and three bedrooms. The site plan includes a green space between the new apartments and the former GSA building. 

The GSA building is 10,000 square feet and was built in 1970 in the modern Brutalist style, known for architecturally beautiful monolithic concrete structures. BHP will seek landmark designation for the building. Office space in the building will be converted to housing.  

Construction is projected to start in 2025.