San Mateo County
Belmont ADU rules
Belmont has an official local rule record in this scrape. Provider research is grouped at the San Mateo County level.
Local rule facts
Min/max ADU size
Min: 150 square feet Max detached (one bedroom or less): 850 square feet Max detached (two bedrooms or more): 1000 square feet Max attached: the greater of 50% of primary dwelling square footage or 850 square feet (one bedroom or less) / 1,000 square feet (two+...
Height
Attached: Same as primary dwelling Detached: 16 feet Over garage: 20-23 feet (dependent on roof style) *Over garage, if setbacks meet underlying zoning regulation: 28 feet
Setbacks
Attached: California Gov. Code, § 65852.2, subd. (a)(1)(D)(vii): 4-feet side and rear Detached: rear and side – 4 feet; front – depends on zoning district; 5 feet from primary dwelling unit
Parking
No parking required but, if provided, can be tandem
Owner occupancy
Owner must live in the main dwelling or the ADU unless ADU was permitted between Jan 1 2020 and Jan 1, 2025
Process
-at-a-Glance FAQs Floorplans Inspiration Glossary Guidebook + Exercises Pre-Designed Plans Process-at-a-Glance See the resources page Events About Contact Getting Started Learning the Rules Budgeting Design Permitting Construction Renting Getting Started Learning the...