Bolthole Index

San Mateo County, California

Zoning, building permits and septic rules in the Town of Colma, California

The Town of Colma, California adopts and administers its own zoning ordinance1. Colma's Building Division issues building permits and conducts building inspections inside town limits2. San Mateo County's rules for unincorporated land do not apply inside Colma. We could not confirm who permits septic systems inside the town; ask San Mateo County Environmental Health Services3.

At a glance

Zoning
Colma adopts and administers its own zoning ordinance1
Building permits
Issued by the Town of Colma Building Division, with inspections2
Septic
Not confirmed inside town limits; ask San Mateo County Environmental Health Services3
Manufactured homes
Permitted in the R and R-S residential zones45
Residential height limit
36 feet in R, 27 feet in R-S67
RV and tiny-home living
Not confirmed; ask the Planning Department8

Who to call

Building permits

Town of Colma Building Division

Building permits, plan review and building inspections inside the Town of Colma

(650) 757-8888

building@colma.ca.gov

1198 El Camino Real, Colma, CA 94014

Zoning

Town of Colma Planning Department

Zoning code administration and current planning applications inside the Town of Colma

(650) 757-8888

planning@colma.ca.gov

1198 El Camino Real, Colma, CA 94014

Septic permits

San Mateo County Environmental Health Services

County septic (OWTS) permits and water-well drilling permits; whether its service area includes parcels inside Colma is unconfirmed

(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 Town of Colma means bringing your own water and power. The kit we’d start with:

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Does Colma have zoning, and what does it mean for homes, lot size and setbacks?

Yes. The Town of Colma adopts and administers its own zoning ordinance, and no building or land inside the town may be used except as the zoning code allows1. The Planning Department maintains and administers the Colma Zoning Code8.

Two residential zones matter most for a home. In the R Residential Zone, a single-family dwelling or a manufactured home is a permitted use4. The same two uses are permitted in the R-S Sterling Park Neighborhood Residential Zone5.

In the R zone, lots need a minimum average width of 33.33 feet and a minimum depth of 100 feet9. The R-S zone uses the same two figures10. Structures in R are capped at 36 feet6; in R-S the cap is 27 feet7.

What are the setback rules in Colma's residential zones?

In the R zone, the front setback is 15 feet and the side setback is 10% of lot width or 10 feet, whichever is less11. The rear setback in R is 25% of total lot area, not to exceed 25 feet or 15 feet, with Section 5.03.082(3) adding an exception11.

In the R-S zone, the dwelling sits 15 feet from the front property line and the garage 19 feet, and at least 60% of the front setback area must be landscaped12. Rear setbacks in R-S are 25 feet for a two-story house and 15 feet for a one-story house, and the side setback is 10% of lot width or 10 feet, whichever is less12.

We could not confirm a residential lot-coverage percentage or a minimum dwelling size in these zones, so ask the Planning Department before you design8.

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

Building permits inside the Town of Colma come from the Town's own Building Division, which also conducts building inspections2. The Division says it guides applicants through plan review and permit requirements2.

We could not confirm the full list of work that needs a Colma building permit, or any owner-builder exemption inside town limits. Call the Building Division at (650) 757-8888 before you assume any project is exempt2. California's owner-builder licensing exemption exists statewide, but it is a licensure rule and does not itself remove a permit requirement13.

San Mateo County's Planning and Building Department handles building permits only for unincorporated land14. A Colma address belongs at the Town counter, not the county's.

How do septic permits work inside Colma?

We could not confirm who permits septic systems or wells on parcels inside Colma. County sources do not state whether San Mateo County Environmental Health's service area includes incorporated Colma, and no Colma rule on septic was located.

For context, San Mateo County requires a permit from Environmental Health to install an individual sewage disposal system elsewhere in the county15. Environmental Health administers local septic oversight under a state-approved program16. Ask Environmental Health Services at (650) 372-6200 whether a septic or well permit applies to your Colma address3.

We also could not confirm whether a new Colma home must connect to public sewer and water. Ask the Building Division when you apply2.

Can you live in an RV or tiny home on your land in Colma?

We could not confirm any Colma rule on living in an RV, temporary camping, or tiny homes on private land. Ask the Planning Department at (650) 757-8888 before you move one onto a lot8.

Do not use San Mateo County's RV rules as a stand-in. Those apply to unincorporated land, and the county's temporary-living provision is tied to its own zoning chapter, not to incorporated towns17. Manufactured homes are the one factory-built option the Colma zoning code confirms, in the R and R-S zones4.

Building a home in Colma: the steps, in order

  1. Confirm the parcel is inside Colma and not unincorporated county land; the Building Division points unincorporated or Broadmoor addresses to the county2.
  2. Check the parcel's zoning district with the Planning Department, since lot size, height and setbacks differ between R and R-S1.
  3. Ask the Planning Department which planning approvals your project needs8.
  4. Apply to the Building Division for a building permit and plan review2.
  5. Ask San Mateo County Environmental Health Services whether any septic or well permit applies to the address3.
  6. Schedule building inspections with the Building Division as work proceeds2.

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

Land outside Colma's limits follows San Mateo County's rules instead; see the San Mateo County page for unincorporated land. The county's zoning information does not cover properties within city limits, so a Colma parcel's zoning comes from the Town18.

County-level figures give context only. San Mateo County's typical home value is about $1,595,76419 and its effective property tax rate is about 0.6%20. Confirm flood, driveway and fee details with the Town: we could not confirm a Colma fee schedule, driveway rules or floodplain standards beyond a flood hazard zone in the zoning code2.

Watch-outs

  • Some addresses with a Colma mailing address are actually unincorporated or in Broadmoor, where San Mateo County, not the Town, handles building permits2.
  • We could not confirm Colma's permit exemptions, owner-builder rules, fee schedule or septic authority; call the Building Division before you spend money on plans2.
  • Residential zoning limits differ between the R and R-S zones, so confirm your parcel's district before using any height or setback figure1.

Sources

  1. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  2. Town of Colma Building Division (colma.ca.gov)
  3. San Mateo County Environmental Health Services (smcgov.org)
  4. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  5. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  6. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  7. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  8. Town of Colma Planning Department (colma.ca.gov)
  9. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  10. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  11. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  12. Colma Municipal Code Chapter 5.03 Zoning (Town of Colma), quoted and re-checked
  13. Owner-Builder Overview, quoted and re-checked
  14. Apply for a Permit, quoted and re-checked
  15. Land Use, Septic & Wells, quoted and re-checked
  16. Land Use, Septic & Wells, quoted and re-checked
  17. San Mateo County Zoning Regulations, quoted and re-checked
  18. Get Zoning Information, quoted and re-checked
  19. Typical home value (Zillow): Bolthole Index county data
  20. Effective property tax rate: Bolthole Index county data

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 Town of Colma

Town of Colma’s own rules

  • Local zoningPresent

    Land inside the Town of Colma. Colma adopts and administers its own zoning ordinance.

    • The zoning map and district boundaries are incorporated into the ordinance.
    “No person may use, design, or intend to be used, any building or land in the Town, except for the purposes specified in, and in compliance with, the provisions of this subchapter.”
  • Minimum lot sizeSpecified

    R Residential Zone inside Colma town limits.

    minimum average lot width: >= 33.33 feet · minimum lot depth: >= 100 feet

    “Minimum Average Width (feet) 33.33 [...] Minimum Depth (feet) 100”
    One more reviewed finding on this topic
    • Specified — R-S Sterling Park Neighborhood Residential Zone inside Colma town limits.
      “Minimum Average Width (feet) 33.33 [...] Minimum Depth (feet) 100”
  • SetbacksSpecified

    R Residential Zone inside Colma town limits.

    • The table identifies the rear setback as 25% of total lot area, not exceeding 25 feet or 15 feet under Section 5.03.082.

    front setback: 15 feet · rear setback: 25% of total lot area, not exceeding 25 or 15 feet (See Section 5.03.082(3).) · side setback: 10% of lot width or 10 feet, whichever is less

    “Front Setback (feet) 15 [...] Rear Setback (feet) 25% total area of lot, not exceed 25’ or 15’ (see 5.03.082(3)) [...] Side Setback (feet) 10% width of lot or 10’, whichever is less”
    One more reviewed finding on this topic
    • Specified — R-S Sterling Park Neighborhood Residential Zone inside Colma town limits.
      “15’ property line to front face of dwelling, 19’ from front property line to front face of garage. At least 60% of front setback area must be devoted to landscaping. [...] 25’ for two story, 15’ for one story [...] 10% width of lot or 10’, whichever is less”
  • Building heightSpecified

    R Residential Zone inside Colma town limits.

    maximum structure height: <= 36 feet

    “Maximum Structure Height (feet) 36’ 27’ -”
    One more reviewed finding on this topic
  • Manufactured homesAllowed

    Manufactured homes in Colma's R Residential Zone.

    • Other building, zoning, safety, and permit requirements still apply.
    “The following uses are permitted on land located within the "R" Zone: (1) A single-family dwelling; (2) A manufactured home;”
    One more reviewed finding on this topic
    • Allowed — Manufactured homes in Colma's R-S Sterling Park Neighborhood Residential Zone.
      “The following uses are permitted on land located within the “R-S” Zone: (1) Single-family dwelling; (2) A manufactured home;”

Still unanswered

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

  • Building permit — Building permits for construction inside Colma town limits.
  • Owner-builder exemption — Owner-builder exemptions inside Colma town limits.
  • Building code adopted — Building-code adoption for land inside Colma town limits.
  • Inspections — Building inspections inside Colma town limits.
  • Certificate of occupancy — Certificates of occupancy for buildings inside Colma town limits.
17 more unanswered
  • Minimum dwelling size
  • Lot coverage
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Who permits septic
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Agricultural exemption
  • Subdividing land
  • Driveway access
  • Building in a floodplain
  • Short-term rentals
  • Permit fees

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 Town of Colma 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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