San Mateo County · Building on your lot
Building on your lot in San Mateo County
San Mateo County's code applies only in unincorporated areas of the county. There it limits oversized vehicle parking on posted county roads and requires covers on new pools and hot tubs.
Key points
- Oversized vehicles: Oversized vehicles over 6 feet high and trailers may stay in posted no-oversized-parking zones at most 8 hours, only for emergency repairs or towing.
- Pool covers: San Mateo County requires covers on all new swimming pools and hot tubs in unincorporated areas.
Each rule below is marked San Mateo County code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.
San Mateo County's code applies in the unincorporated areas of the county. Cities in San Mateo County have their own codes and their own pages.
RV and boat parking
| Parking on the street |
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Swimming pools
| Maintenance and empty pools |
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Family child care homes
| Zoning | A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning |
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| Business license or fee | A city or county may not charge a business license, fee or tax to run a family child care home |
| Local rules | Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone |
| Small home | Up to eight children, counting the provider's own children under 10 who live there |
| Large home | 7 to 14 children, counting the provider's own children under 10 who live there |
Affordable units in new housing (inclusionary)
San Mateo County code Affordable for 55 years. Exempt: residential projects subject to the cited zoning regulation sections, and accessory dwellings created under the zoning regulations.
All 4 San Mateo County rules on affordable units in new housing (inclusionary), with the code text →
Trash and recycling carts
San Mateo County code Minimum curbside collection service levels are set for residential properties Within 24 hours
All 4 San Mateo County rules on trash and recycling carts, with the code text →
Other San Mateo County rules on this
San Mateo County's code also has these chapters. We have not summarized their values on this page yet; read them in the library.
- Permit to keep more dogs and cats (Ch. 6.16)
- Erosion control during construction (§ 4.100.210)
- Noise control (Ch. 4.88)
Who this affects
Frequently asked questions
Can I park an RV or boat at my home in San Mateo County?
Oversized vehicles over 6 feet high and trailers may stay in posted no-oversized-parking zones at most 8 hours, only for emergency repairs or towing.
What are the pool fence and setback rules in San Mateo County?
San Mateo County requires covers on all new swimming pools and hot tubs in unincorporated areas.
Can I run a family child care home in San Mateo County?
California law sets this for every city, including San Mateo County: Zoning: A small or large family child care home is a residential use and a use by right under all local ordinances, including zoning (Health & Safety Code § 1597.45(a)); Business license or fee: A city or county may not charge a business license, fee or tax to run a family child care home (Health & Safety Code § 1597.45(b)); Local rules: Local limits on height, setbacks, lot size, health and safety must be the same as for every other home in the same zone (Health & Safety Code § 1597.45(e)); Small home: Up to eight children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(c)); Large home: 7 to 14 children, counting the provider's own children under 10 who live there (Health & Safety Code § 1596.78(b)).
General information, not legal advice.
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