David Baker Architects | Location: Oakland, CA
Coliseum Place is an affordable housing development currently under construction on the border between a planned high-density TOD at the Coliseum BART Parking Lot, and a neighborhood of single-family homes in central East Oakland. The six-level, 80,000 SF building will include 58 affordable family homes, including 25% reserved for the unhoused, and 25% fully accessible for mobility-impaired residents. The building was a part of the International Living Future Institute’s affordable housing pilot program, and pursued a full-ZNE design centered around an innovative, and very inexpensive decentralized, shared heat pump hot water system, in which one 80-gallon hybrid heat pump serves two units, with 3/8” home runs employed to deliver hot water in 10-30 seconds. Heat recovery ventilators and packaged heat pumps serve residential HVAC needs, and the final design includes a roof-mounted PV array covering roughly 40% of the building’s loads. The predicted net energy use intensity for this 6-story project is below 10 kbtu/sf-year.
The design concept revolves around the idea of connecting residents to nature and to each other. A grand, exterior stair with timber bamboo growing through the center draws residents up from a welcoming lobby and links community space, a 2nd floor courtyard, bike storage rooms, and 6th floor laundry with sweeping views of the East Bay hills. Enclosing this experience, the building design is a simple mass with textured façade treatments that are well-tuned to the building’s orientation, including a perforated metal screen across the southwest façade, designed to cut solar gains and impart an experience of dappled daylight in the units facing the sun.
In evaluating the feasibility of the Living Building Challenge for this project, the design team developed a scheme to treat 100% of stormwater and greywater on-site, re-use greywater for toilets, irrigation and laundry, and send the remainder to the stormwater system. The budget ultimately did not allow us to pursue this system. With the help of the distributed hot water system that dramatically cut energy loads, a structural steel canopy that extended a few feet over the building footprint would have been enough to achieve zero net energy and would have been a financial benefit to the owner. However, as a construction budget item, the system was too risky for this tax-credit project to include. Although these infrastructure features did not ultimately survive in the project, the team became better able to navigate barriers to achieving deep energy and water reductions for low-income housing projects.