Union recently participated in the Denver Single-Stair Housing Challenge, organized by Buildner and SAR+ Architects as part of Buildner’s ongoing Affordable Housing Challenge series. The competition invited designers worldwide to rethink mid-rise housing in Denver through single-stair design (also referred to as point access block or PAB) — a typology used internationally but rarely seen in North America due to code limitations requiring two egress stairs. Single-stair circulation, where one fire-rated stair serves all units from within 20 feet of each entry, means fewer structural demands and more room for housing, community amenities, and open space.
Our team focused on a site in Capitol Hill, conceptualizing what they called “Remix Denver” with a core vision of dense urban housing as an engine of mobility and opportunity.
“Remix Denver” creates a vibrant ecosystem where residents can transform from renters to owners, entrepreneurs can test up pop-up shops or maker spaces on the ground floor, and neighbors can gather in flexible communal areas. To encourage broader affordability and flexible living arrangements, the concept proposes integrating additional dwelling units (ADUs) and modified zoning requirements like zero-lot-line setbacks, parking reductions near transit, and single-stair allowances.
Modular, off-site construction of individual units supports ease of adaptability for any site or developer proforma by effortlessly “remixing and matching” the unit type modules while keeping the typical construction and building envelope details the same. Supporting the advancement Denver’s climate goals, Union’s team promoted Passive House–aligned detailing and energy performance, specifying Red List Free materials to promote healthier indoor air quality, and solar-ready roofs.