For years, builders across the western and southwestern regions have been moving in piecemeal efforts toward developing Net-Zero Energy (NZE) housing models for mass production, as new regulations envision the near-future proliferation of NZE building types, and energy-conscious consumers begin to ask for these structures as well. NZE buildings—a widely and variously defined concept—generally produce as much energy as they consume over the course of a year. They aim to reduce overall energy consumption while also generating renewable energy on site.
Builders have discovered that the best way to standardize NZE building methods is to lower overall building energy consumption first, and only then tackle costly additions like green technology. That means increasing insulation values within building walls while also tightening the exterior envelope. It is also important to place mechanical equipment within conditioned spaces and to program interior spaces with an eye toward solar exposure. After energy-efficient appliances are specified and a building energy analysis is conducted, designers move to size energy systems appropriately for the remaining energy loads. This tactic generates tight, efficient buildings that require smaller and cheaper solar panel installations. Because many of the building-related approaches—like constructing walls out of larger two-by-six-foot studs to create a wider insulation cavity—are easy to do and do not require builders to learn new skills, these approaches have brought down the potential cost of NZE buildings substantially.
Using the above strategies, builders like Phoenix, Arizona–based MODUS Development are helping to bring NZE residential buildings into the mainstream even further by developing NZE buildings with contemporary massing and detailing at both single- and multifamily scales.
Ed Gorman, founder and president of MODUS, has been hard at work streamlining and modernizing existing NZE housing models in an effort to stay ahead of California’s plan to have all single and most multifamily residential construction be NZE-equivalent by 2020. When the change comes, MODUS will be ready. Gorman expects the housing market to move toward the wide adoption of NZE homes either way.
MODUS has completed work on several NZE developments across California and Arizona so far—most recently, a 41-unit development called Equinox in Scottsdale, Arizona. The project—the first NZE apartment complex in Arizona—is organized around a central courtyard, and the one- and two-story units feature deeply recessed balconies and loggia spaces. Gorman explained: “The balconies serve as a heat sink” to facilitate passive ventilation, and the structures “create shade directly from the architecture, the way a modernist building would, instead of as an applied afterthought.” The project came in at the same cost as a non-NZE construction and is fully occupied. The firm’s portfolio for the year includes three new NZE developments: two 20-townhome developments in Scottsdale and a 32-unit multifamily development in Tempe, Arizona.
For Gorman, the NZE strategy is a no-brainer. “Highly efficient buildings have higher tenant retention, often sell for as much if not more, and cost less to build than traditional buildings,” he said. “If you can make it work in the desert of Arizona, you can make it do anywhere.” The future of building in Arizona and California, it seems, is heading toward Net-Zero.