HEART of San Mateo County makes free, all-electric detached ADU designs available through its GLADUR program. The designs can reduce drafting work and may receive partial pre-review in participating cities. They do not establish that a parcel can fit the unit or guarantee a permit.
Choose among four detached designs
The ADU Center lists a 400-square-foot studio, a 575-square-foot rectangular one-bedroom plan, a 745-square-foot square one-bedroom plan, and an 800-square-foot two-bedroom plan. Users must sign HEART’s agreement to access the designs. They are starting points: zoning, building code, fire access, utilities, grading, easements, and site dimensions still affect a project.
Confirm whether a city participates
HEART’s current pre-review list names Foster City, South San Francisco, Redwood City, East Palo Alto, Daly City, and Belmont. Review depth differs by city. All participating cities still require a site plan, and a nonconforming site or material design change can trigger full site and construction-plan review.
Before selecting a plan, ask the city’s permit office which GLADUR version it accepts, what pre-review covers, what local corrections are required, and whether property constraints make a standard design unsuitable. The catalogue is not a site survey, zoning determination, building permit, utility-capacity confirmation, or cost estimate.
For other public help with plans and early review, see Fee waivers, pre-approved plans, and technical assistance. Confirm local unit-count rules separately in the San Mateo ADU eligibility guide.
Key points
- HEART provides four free all-electric detached designs through a signed user agreement.
- Six named cities offer some form of pre-review, with different review depth.
- A site plan and local fit review remain necessary; nonconforming conditions or material changes can require full review.
- Confirm the local process and parcel constraints before budgeting around a standard plan.