by Stacey Hobart, New Buildings Institute
The zero net energy (ZNE) homes market is just beginning to emerge, according to a recent report from Navigant Research called ZNE, Near-ZNE, and ZNE-Ready Homes: Market Drivers, Case Studies, and Forecast Data. Growth is expected to reach 27,000 total units by 2025, and is being driven by increasing stringency in building codes, the potential for onsite generation to help tackle growing grid loads, and mainstreaming of new technologies.
Most of the current count of ZNE single-family homes in the North America are located in California with inventory largely limited to custom projects by small builders, the report says. However, a recent announcement from Pulte Group may signal a sea change for the ZNE residential market. The company, which is the third largest U.S. home builder, stated that it is now producing a ZNE home prototype. The number of multi-unit projects is poised to grow, says Shilpa Sankaran of the Net Zero Energy Coalition, which tracks cases of ZNE single-family and multifamily projects.
“Ninety-five percent of ZNE homes that we identified through our study were part of developments that included two or more homes,” said Sankaran. “The largest multifamily development is 540 units.” In addition, the U.S. Department of Energy’s (DOE) Zero Energy Ready Homes program reports that thousands of “additional properties are in the pipeline.”
The Atlanta-based Pulte created the prototype for the Pacific Gas and Electric Company’s (PG&E) Zero Net Energy Production Builder Demonstration pilot, which is working to achieve maximum home efficiency as well as utility grid load reduction. The recently completed Pulte ZNE home prototype, located in Brentwood, Calif., combines airtight building methods, high-efficiency insulation, HVAC, lighting technologies and more, with on-site solar energy production to offset the home’s energy consumption, according to the company announcement. “The Pulte ZNE prototype will help guide and create best practices for the company in building more energy efficient new homes in California and, ultimately, across the nation,” said Ryan Marshall, president of PulteGroup. “Our goal for this prototype is to help define the most efficient path to building zero net energy homes that effectively balance constructability, cost and quality.”
The Pulte prototype builds on several demonstrations in California dating back to 2012 when the first ABC Green Home was constructed in Irvine. In all, four ABC Green Homes that feature zero net energy performance have been built or are planned around Southern California. Another national homebuilder KB Home has built 12 ZNE demonstration homes around the country since 2011, including four in California.
Since KB Homes’ first concept house went on display during a builder show in Orlando, construction costs for net-zero homes have dropped 50% and the time needed to build them has been reduced 7%, explained Jacob Atalla, KB Home’s vice president of sustainability. “We’re beyond building homes for R&D,” he said. The company plans to launch sometime in the next year its first net-zero community for the mass market somewhere in Southern California.
Read Pulte’s announcement
See a video about the Pulte ZNE Home Prototype
Read about the ABC Home
Read the recent New York Times Article on ZNE homes, “A Suburban Experiment Aims for Free Energy”