ZERO ENERGY FOR RESIDENTIAL
PULTE ZNE RESIDENCE CASE STUDY, BRENTWOOD, CA
Under the auspices of PG&E’s Zero Net Energy (ZNE) Production Builder Demonstration, PulteGroup built a 2,359 square foot ZNE home in Brentwood, CA with a semi-conditioned attic and an air source heat pump. This report describes the results from monitoring the occupied home for a full year.
The Pulte ZNE home was completed in May 2016. The process of
completing the ZNE home with PG&E is already influencing how
PulteGroup is proceeding with new homes in California.
HABITAT FOR HUMANITY HOME
Habitat for Humanity of San Joaquin County (SJC Habitat) partnered with PG&E in the ZNE Production Builder Demonstration beginning in 2015. This demonstration home is “Home 10” in the Dream Creek Subdivision in Stockton, CA, where SJC Habitat has been continuously improving the energy efficiency measures of their prototype home.
Resource Refocus provided general project oversight and data analysis on behalf of PG&E, Ann Edminster, Rick Chitwood, and Steve Easley provided design consulting, and Frontier Energy (Davis Energy Group) is conducted the performance monitoring.
FINDINGS | For Habitat for Humanity San Joaquin Valley, the ZNE measures, in aggregate, reduced the net cost of the home by nearly $3,000 as a result of a holistic, highly integrated approach. For example, moving from 2x4 16” o.c. wall construction to 2x6 24” o.c. saved money on lumber and improved the thermal envelope, which allowed the HVAC system to be downsized.
PG&E Currents - PG&E, Habitat for Humanity Dedicate New Zero Net Energy Home to Deserving Families (March 1, 2016)
ZNE PRODUCTION HOME BUILDER PROGRAM
Pacific Gas and Electric Company (PG&E) implemented a Zero Net Energy (ZNE) Production Builder Demonstration that supported six builders in California in designing and monitoring a ZNE house. Each builder received technical support from start to finish to upgrade one of their existing prototypes to ZNE while preserving their look and feel. The ultimate goal was to achieve a ZNE home that the builder could replicate to begin to build ZNE homes at scale. For each builder, the design consultants recommended energy efficiency measures for the builder’s standard design based on performance modeling and substantial past experience with ZNE and energy-efficient homes. As part of this offering, PG&E reimbursed up to $15,000 in incremental cost of the energy efficiency measures; experience shows that the incremental costs will drop in subsequent projects. Finally, the monitoring consultants tracked the end-use energy consumption of the completed home for a year after occupancy to determine whether the ZNE home is performing as designed and to diagnose any operational issues.