Montclair · Building on your lot
Building on your lot in Montclair
Montclair limits accessory structures on R-1 lots by lot size and requires a permit for a home occupation. It also sets minimums for pool enclosures, flood-zone floor heights and residential parking.
Key points
- Accessory structures: On R-1 lots, accessory structures are limited to 1 story or 15 feet and 200 to 1,400 total square feet, depending on lot size.
- Home businesses: A home occupation permit is required, and the business may use no more than 1 room and employ only resident family members.
- SB 9 lot splits: Each new lot must be 40% to 60% of an original lot of at least 2,400 square feet, and at least 1,200 square feet.
- Pool enclosures: Pool enclosures must be at least 5 feet high, and self-latching gate devices at least 4 feet 6 inches above ground.
- Flood zones: New or substantially improved homes in Zones AE, AH and A1-30 must have the lowest floor, including basement, 2 feet above base flood elevation.
- Parking: Required parking spaces must be at least 9 by 20 feet; duplex and multifamily units need at least 2 spaces in an enclosed garage.
Each rule below is marked Montclair code or CA state law and links to the section it comes from (checked October 2026). General information, not legal advice.
Sheds, garages and other accessory structures
Montclair code On R-1 lots, accessory structures are limited to 1 story or 15 feet and 200 to 1,400 total square feet, depending on lot size.
All 8 Montclair rules on sheds, garages and other accessory structures, with the code text →
Running a business from home
Montclair code A home occupation permit is required, and the business may use no more than 1 room and employ only resident family members.
All 5 Montclair rules on running a business from home, with the code text →
Lot splits under SB 9
Montclair code Each new lot must be 40% to 60% of an original lot of at least 2,400 square feet, and at least 1,200 square feet.
All 7 Montclair rules on lot splits under SB 9, with the code text →
Swimming pools
Montclair code Pool enclosures must be at least 5 feet high, and self-latching gate devices at least 4 feet 6 inches above ground.
All 8 Montclair rules on swimming pools, with the code text →
Building in a flood zone
| Floodplain permit |
|
|---|---|
| Building in a floodway |
|
| Height of the lowest floor |
|
Grading and erosion control
| Erosion control plan |
|
|---|
Garage and yard sales
Montclair code No more than 3 days in a row, on any days of the week. No more than 3 days in a row, on any days of the week.
All 5 Montclair rules on garage and yard sales, with the code text →
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 |
|---|---|
| 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 |
Parking spaces required for homes
Montclair code Required parking spaces must be at least 9 by 20 feet; duplex and multifamily units need at least 2 spaces in an enclosed garage.
All 9 Montclair rules on parking spaces required for homes, with the code text →
Home alarm permits and false alarms
| When a permit can be revoked |
|
|---|
Signs on homes
Montclair code Not sooner than 60 days before the election At most 8 square feet; a double-faced sign may be 8 square feet on each side
All 10 Montclair rules on signs on homes, with the code text →
Historic homes
Montclair code Goes to the Historic Preservation Commission if the Planning Division finds the work affects the exterior appearance Only the City Council may approve, and only on a showing of hardship
All 3 Montclair rules on historic homes, with the code text →
Other Montclair rules on this
Montclair's code also has these chapters. We have not summarized their values on this page yet; read them in the library.
- Parking RVs, oversized vehicles and trailers on the street (Ch. 8.38) — on public streets
- RV garages on a single-family lot (§ 11.19.110) — single-family zones only
- Permit for rooftop solar on a home (§ 10.20.030) — the next section covers EV charger permits
- Noise limits by zone (§ 6.12.040)
- Transportation impact fees (Ch. 3.18)
Who this affects
Frequently asked questions
What are the rules for building in a Montclair flood zone?
New or substantially improved homes in Zones AE, AH and A1-30 must have the lowest floor, including basement, 2 feet above base flood elevation.
What are the grading rules in Montclair?
Montclair's code: All projects that need a grading permit must submit erosion and sediment control plans for approval. (§ 9.24.430).
Can I run a family child care home in Montclair?
California law sets this for every city, including Montclair: 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)).
Do I need a permit for a home alarm in Montclair?
Montclair's code: The permit is revoked on the Police Chief's recommendation after more than 6 false alarms in any consecutive 365-day period (§ 4.12.110).
General information, not legal advice.
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