Denver’s Petroleum Building to become new residential complex

The Petroleum Building, a midcentury office tower in downtown Denver, is set to be converted into residential apartments under a new adaptive reuse project backed by the Denver Downtown Development Authority.

The DDA announced Wednesday that it has issued a loan commitment to support the redevelopment, which will transform the 14-story, 200,000-square-foot building at 16th Street and Broadway into 178 market-rate rental units. Plans call for studio, one, two and three bedroom apartments, addressing a growing need for housing in the city’s core as office vacancies continue to rise.

Developer Tim Borst is leading the project on behalf of the ownership group, which includes Borst & Company and DellaCava Holdings. The group purchased the building in 2005. Architectural firm Gensler and PCL Construction are guiding the design and engineering work, drawing on experience in office-to-residential conversions.

Borst said the project aligns with broader efforts to reinvigorate downtown by converting underused office buildings and restoring historic assets. Funding will be supported by DDA financing, state and federal historic tax credits and private investment. The redevelopment has also received support from the mayor’s office.

Plans for the building include a penthouse dog park and lounge, workspaces and on-site electric car sharing. The property is located near Civic Center Park, which is slated for upgrades, and within walking distance of museums, restaurants and other downtown amenities.

Jon Gambrill, co-managing director of Gensler’s Denver office, said the design will emphasize the building’s historic character while creating modern living spaces. The project will restore the facade to reflect its original midcentury form and serve as a gateway to 16th Street.

The DDA funding requires final approval from the Denver City Council. Developers expect to break ground in late spring 2026 and complete construction in summer 2027.