StopWaste, a public agency based in Alameda County, California, has promoted green building and green labeling since the early 2000s. Past initiatives include a study by the University of California on the value of green labeling at time of sale, which showed a 6% premium for green homes in California. StopWaste has also convened a statewide Green Real Estate Working Group comprised of utility, local government and private-sector program implementers in the residential sector.

StopWaste became an HES partner in 2015. In 2018, StopWaste, in partnership with the Bay Area Regional Energy Network (BayREN), launched a Home Energy Score program in the 9-county San Francisco Bay Area. Current Assessors include building contractors and home inspectors. Low-scoring homes are referred to BayREN’s free Home Upgrade Advisor service, which helps homeowners participate in local rebate and financing programs.

In addition to running the Home Energy Score program through the BayREN partnership, StopWaste also provides training and resources for real estate professionals who are interested in becoming green home experts.

StopWaste and BayREN were approved by the California Public Utilities Commission to launch a statewide program, Home Energy Score California, in 2026.