Compare cities · Santa Clara County
A two-track code: take the state baseline (800 sq ft, 16 to 18 ft) with no strings, or opt into city standards that allow 900 to 1,000 sq ft and up to 800 sq ft above your FAR and lot-coverage caps in exchange for a set of privacy rules. Impact fees are real money above 750 sq ft; the city's own estimate runs $10,000 to $80,000.
Pre-approved detached designs on the ADU Accelerator gallery; a gallery plan removes the architectural review of the structure, and a site-specific building permit is still required. Under state law a detached unit built from a pre-approved plan gets a 30-day decision instead of 60.
Program page →900 sq ft (one bedroom) or 1,000 sq ft (two or more), plus up to 800 sq ft above FAR and lot coverage, in exchange for privacy standards on entry orientation, window sills, deck screening and lighting.
Units under 750 sq ft, JADUs, and garage or carport conversions with no FAR expansion are exempt from development impact fees (FY26 fee sheet).
State law sets a floor no ordinance can go under. The full guide, with every statute cited →
Every lot zoned for residential use may have at least one ADU, and a single-family lot may also add a JADU. A city cannot say no to the category.
A detached or attached unit of up to 800 sq ft, 16 ft tall, with 4 ft side and rear setbacks must be approved regardless of local lot-coverage or floor-area limits.
A city cannot require more than four feet from side and rear lot lines for an ADU.
Once your application is complete the city has 60 days to approve or deny; 30 if you build from a pre-approved plan.
Convert or demolish a garage to build an ADU and the spaces you lose never have to be replaced.
Prohibited entirely below 750 square feet, and proportional above it.
Reviewed against an objective checklist. No design review board, no hearing, no discretion about whether they like it.
A city cannot require you to live on the property for a standard ADU. A JADU is different: since 1 January 2026 owner occupancy is required when the JADU shares sanitation with the main house.
Palo Alto is inside our service area, and ADUs are all we do. We bring in the architect and engineer or work with yours, run the permit with Palo Alto, and build with our own crew: about 6 weeks of construction for a detached unit once the permit is in hand.
What we can't tell you from here is what your particular lot will take: setbacks, the sewer lateral, the panel, grade and access. That is what the free site walk is for.
Tell us about your lot and what you're hoping to build. We'll reach out to set a time to walk it with you. No obligation.
Thanks. We've got your details and sent a confirmation to …. Sam or Brad will reach out shortly to set a time for the walk.