Bolthole Index

San Mateo County, California

Zoning, building permits and septic rules in Belmont, California

The City of Belmont, California, in San Mateo County, has its own zoning ordinance and adopts the 2025 California Building Code for buildings inside city limits12. Sleeping in an RV on city streets and in parks is banned overnight3. We could not confirm who handles septic permits inside Belmont, so ask the city building division and San Mateo County Environmental Health.

At a glance

Zoning
Belmont has its own city zoning ordinance1
Building code
2025 California Building Code, adopted by the city2
Sewer connection
Written sewer connection permit from the building official4
RV living
Banned overnight on streets, parks and public ways; emergency housing only by city permit3
Camping
Overnight camping in city parks only at designated locations5
Septic
Not confirmed for Belmont; San Mateo County runs the countywide septic program6

Who to call

Building permits

City of Belmont Community Development Department (Building Division and Planning)

Belmont's own building permits, inspections and planning and zoning questions inside city limits

Septic permits

San Mateo County Environmental Health Services

Septic (OWTS) permits and water-well drilling permits administered by San Mateo County

(650) 372-6200

Contact details are copied from each office’s official page and were checked against it on October 16, 2026.

Off-grid gear

Going off-grid in Belmont means bringing your own water and power. The kit we’d start with:

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Does Belmont, California have zoning, and what does it mean for RVs and tiny homes?

Yes. Belmont's city code identifies its own zoning ordinance, so land inside Belmont city limits follows city zoning, not the county's unincorporated-area zoning1. San Mateo County itself says it does not provide zoning information for properties inside city limits and tells owners to contact the city's Planning Department7.

We could not confirm Belmont's district-by-district minimum lot sizes, setbacks, lot coverage, height limits or tiny-home and accessory-dwelling rules, so check the zoning for your exact parcel with the Belmont planning staff before you design anything.

RV living is tightly limited. Belmont bans using a camper, trailer coach or other vehicle for sleeping, eating or resting on any street, park, beach or public way between 10:00 p.m. and 6:00 a.m.3. Temporary housing in a travel trailer or camper in a residential zone is possible only after a city-declared emergency that makes a home uninhabitable, through a city manager permit3. Overnight camping in city parks is unlawful except at designated locations5.

Do you need a building permit in Belmont, and who issues it?

Belmont adopts the 2025 California Building Code by reference as the city's building code, so construction inside city limits is built to that code2. California's 2025 code applies to buildings with a permit application date on or after January 1, 20268.

The city, not the county, handles building permits here. San Mateo County states that its building permits cover only unincorporated areas and that incorporated cities and towns administer their own permitting9. A reader inside Belmont who goes to the county planning counter in Redwood City is at the wrong office.

We could not confirm which small projects Belmont exempts from a building permit, how its inspections are scheduled, or whether it requires a certificate of occupancy. Ask the City of Belmont building division before starting any work.

How do septic permits and sewer connections work inside Belmont?

Inside Belmont, connecting a fixture to a public sewer or sewer lateral requires a written sewer connection permit from the building official and payment of the established fees4. A sewer lateral in a public easement or right-of-way also needs a temporary encroachment permit under Chapter 22 of the city code4.

We could not confirm who permits an onsite septic system inside Belmont city limits. Countywide, San Mateo County Environmental Health runs the local septic program and requires a permit for any individual sewage disposal system610. Call Environmental Health at (650) 372-620011 to confirm whether that program covers your Belmont address.

Building a home in Belmont: the steps, in order

  1. Confirm your parcel's zoning district and limits with Belmont planning staff1.
  2. Design to the 2025 California Building Code the city has adopted2.
  3. Apply for building permits with the City of Belmont, not San Mateo County9.
  4. If the lot is on public sewer, get the written sewer connection permit from the building official4.
  5. If the lot has no sewer, ask Environmental Health about septic permits before you buy10.
  6. Do not plan to live in an RV on the lot while you build; Belmont's city code shows no ordinary-day RV occupancy path3.

What stays with San Mateo County, and what to check before you buy in Belmont

Septic and well permits are county-level programs in San Mateo County. Environmental Health requires a permit for installing individual sewage disposal systems, and a permit to drill a water well1012.

San Mateo County's typical home value is about $1,595,764 and its effective property tax rate is 0.6%1314. Those are county-level figures, not Belmont's. Owner-builders should know California's owner-builder exemption is a contractor-licensing exemption and does not itself remove a building-permit requirement15.

For rules on unincorporated land outside Belmont, see the San Mateo County page.

Watch-outs

  • The county's building, zoning and driveway rules apply only to unincorporated San Mateo County, not inside Belmont city limits9.
  • We could not confirm Belmont's lot-size, setback, height, tiny-home or accessory-dwelling rules; ask Belmont planning staff for your parcel's zoning district1.
  • We could not confirm who permits septic systems inside Belmont; ask the city building division and San Mateo County Environmental Health10.

Sources

  1. Belmont City Code, Chapter 8, Section 8-23 (Belmont), quoted and re-checked
  2. Belmont City Code, Chapter 7, Article IV (Belmont), quoted and re-checked
  3. Belmont City Code, Section 15-82 (Belmont), quoted and re-checked
  4. Belmont City Code, Section 21-20 (Belmont), quoted and re-checked
  5. Belmont City Code, Section 16-29 (Belmont), quoted and re-checked
  6. Land Use, Septic & Wells, quoted and re-checked
  7. Get Zoning Information, quoted and re-checked
  8. Approved Building Standards (California statewide rule), quoted and re-checked
  9. Apply for a Permit, quoted and re-checked
  10. Land Use, Septic & Wells, quoted and re-checked
  11. San Mateo County Environmental Health Services (smcgov.org)
  12. Land Use, Septic & Wells, quoted and re-checked
  13. Typical home value (Zillow): Bolthole Index county data
  14. Effective property tax rate: Bolthole Index county data
  15. Owner-Builder Overview, quoted and re-checked

Written October 16, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.

Answers from the rulebook for Belmont

Belmont’s own rules

  • Building code adoptedAdopted (with conditions)

    Buildings inside Belmont city limits.

    • The 2025 CBC adopts the 2024 International Building Code with necessary California amendments.
    “the 2025 california building code (cbc), california code of regulations, title 24, part 2, adopting the 2024 international building code with necessary california amendments, is adopted by reference as the building code of the city of belmont.”
  • Local zoningPresent (with conditions)

    Land inside Belmont city limits.

    • Belmont City Code identifies Ordinance No. 360, as amended, and later city zoning ordinances as its zoning ordinance.
    “The term "zoning ordinance" shall have reference to Ordinance No. 360 of the City of Belmont, as said ordinance is amended, and all other ordinances hereafter enacted pertaining to zoning in the city.”
  • Living in an RVLimited

    RV, trailer coach, camper, and other vehicle habitation in Belmont city limits.

    • Human habitation in the listed vehicles is prohibited on city streets, parks, beaches, squares, avenues, alleys, and public ways from 10:00 p.m. to 6:00 a.m.
    • Temporary replacement housing in a travel trailer or camper may be allowed in residential zones only when a city-declared emergency and disaster-related uninhabitability conditions are met; the city manager application and permit process applies.

    public-place overnight restriction: 10:00 p.m. to 6:00 a.m. (Applies to the listed public places.)

    “No person shall use or occupy or permit the use or occupancy of any house car, camper, or trailer coach, recreational vehicle or any other motor vehicle, car, truck, or bus, etc., for human habitation, including but not limited to sleeping, eating or resting, either singly or in groups, on any street, park, beach, square, avenue, alley or public way within the city, between the hours of 10:00 p.m. and 6:00 a.m.”
  • Camping on your landLimited

    Overnight camping in Belmont city parks.

    • Overnight camping is unlawful except at locations specifically designated for the activity.
    “it is unlawful for a person to engage in flying model airplanes or drones, games or activities of a hazardous nature that are incompatible with any lawful contemporaneous use, or overnight camping and picnics except at locations specifically designated for such activities.”
  • Mandatory utility hookupSewer (with conditions)

    A fixture connected to a public sewer or sewer lateral inside Belmont city limits.

    • A written sewer connection permit from the building official and established connection fees are required.
    • A sewer lateral in a public easement or right-of-way also requires a temporary encroachment permit under Chapter 22.
    “It is unlawful for any person to connect a fixture to a public sewer or sewer lateral without first obtaining a written sewer connection permit from the building official and paying the established fees for such connection.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Belmont or San Mateo County directly.

  • Owner-builder exemption — Owner-builders inside Belmont city limits.
  • Inspections — Building work inside Belmont city limits.
  • Certificate of occupancy — New or altered buildings inside Belmont city limits.
  • Minimum dwelling size — Residential zoning districts inside Belmont city limits.
  • Minimum lot size — Residential zoning districts inside Belmont city limits.
17 more unanswered
  • Setbacks
  • Lot coverage
  • Building height
  • Tiny homes
  • Accessory dwellings
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Agricultural exemption
  • Subdividing land
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees
  • Permit process

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Unanswered questions are usually a sign that Belmont publishes no rule on the point, not that none exists. San Mateo County’s page lists the county offices to call.

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