HPWH Permitting: San Mateo County Pilot
In anticipation of increased heat pump water heater installations in the Bay Area, due in part to the Bay Area Air District’s Rule 9-6, BayREN funded a pilot in San Mateo County to design and test permitting simplifications. The pilot began with background research in early 2026, gathering data on permitting processes across the county's 21 jurisdictions. From April through September, eight participating jurisdictions pilot tested simplified permitting strategies.
The resulting recommendations and resources are designed to help jurisdictions remove common barriers to HPWH installations while maintaining safety and code compliance. Resources from the pilot will be shared starting in September, with additional tools and resources to be added as they're finalized later this year.
Tools and Templates
The tools and templates below were developed through the pilot and are available for building departments to adapt for their own jurisdictions, covering express permitting pathways, inspection guidelines, standardized online application language, and fee structure recommendations. Additional resources will be added later this year.
Available Now
- Background Research Report
- Strategies for Implementation Report
- San Mateo County Area Express Permit Template
- Statewide Express Permit Template
- San Mateo County Heat Pump Water Heater Web Hub
- Web Hub Toolkit
Coming Soon
- Inspection Technical Diagram
- Permit Fee Guidance (one-pager)
- Single Fee Guidance (one-pager)
- Social Media Flyers and Outreach Templates
- Training Videos for Contractors, Homeowners, and AHJs
Contact Us
For more information
Building departments with questions about implementation are welcome to reach out to the contacts listed below.
Emma Grossman, Sustainability Specialist, San Mateo County Sustainability Department
Alhad Dighe, Program Manager, StopWaste
Please reach out to [email protected] to get connected.