Zoning, building permits and septic rules in Westlake Village, California

At a glance

Zoning

City-adopted zoning; R-1 and RPD single-family districts⁴⁵

Zoning clearance

Required from the city Planning Department before a building permit¹

Building permits

Issued by LA County Building and Safety under contract with the city²

Septic

Local health officer approval for ADUs on private sewage systems; county program handles plans⁶³

ADUs

Allowed only in R-1, RPD and certain North Business Park districts⁷

Floodplain

Development permit from the City Engineer in flood hazard areas⁸

RV and tiny homes

Not confirmed; ask the Planning Department¹

Who to call

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

Does Westlake Village have zoning, and what does it allow?

Yes. Westlake Village adopts and enforces its own zoning code inside city limits⁴. Single-family homes sit in the R-1 and several RPD (Residential Planned Development) districts, and the city also has a business park zone⁵.

Rules for RVs, tiny homes, minimum home size, lot size and setbacks in the R-1 district are not something we could confirm, so call the Planning Department before you rely on any of them¹. Los Angeles County's Title 22 zoning applies only to unincorporated land, not to property inside Westlake Village⁹.

Many properties carry a Westlake Village mailing address without being inside the city, so check your parcel with the city before assuming these rules apply¹.

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

New ADUs inside Westlake Village need a building permit from the Building Official plus a zoning clearance from the Planning Director¹⁰. Other improvements follow the same order: the city's zoning clearance first, then the building permit¹.

The city does not run its own building counter. Westlake Village contracts with Los Angeles County to provide building and safety services, and the county's Calabasas permit office handles applications, plan check and inspections².

Owner-builders in California remain responsible for obtaining building permits and passing inspections¹¹.

How do septic permits work in Westlake Village?

Septic is the piece the city does not decide. For an ADU that will use a private sewage disposal system, the code requires approval by the local health officer, and it does not name which agency that is⁶. We could not confirm whether the Los Angeles County Department of Public Health's program covers a given Westlake Village address, so ask the program directly³.

Where the county does act, its program reviews and approves septic plans in unincorporated areas and contracted cities¹². California's statewide policy leaves septic implementation to the state and regional water boards and local agencies¹³.

We found no rule on wells inside the city, so confirm with the city before planning one.

Can you build an ADU or split a lot in Westlake Village?

ADUs are permitted only in the R-1 and RPD zones and in the Mixed Use Lindero and Mixed Use Corsa districts of the North Business Park Specific Plan⁷. A new detached ADU is capped at 850 square feet for up to one bedroom or 1,000 square feet for two or more, and is generally limited to 16 feet in height with 4-foot side and rear setbacks⁷. In a Very High Fire Hazard Severity Zone only one ADU or JADU is allowed⁷.

An ADU or JADU may not be rented for less than 30 days¹⁴.

Urban lot splits in single-family zones require each new lot to have at least 1,200 square feet¹⁵.

Can you live in an RV or tiny home in Westlake Village?

We could not confirm any city rule on living in an RV, camping on a lot or placing a tiny home in Westlake Village. Treat the answer as unknown until the Planning Department tells you otherwise, and ask before you buy¹.

The nearest firm facts are the ADU rules: a new ADU inside the city must go through zoning clearance and a building permit¹⁶. Los Angeles County's rule for manufactured homes applies to unincorporated land, not to property inside the city¹⁷.

Building a home in Westlake Village: the steps, in order

1. Confirm with the Planning Department that your parcel lies inside the city and learn its zoning district¹.
2. Get homeowners association approval if the project is residential, then apply for a zoning clearance with the $50 application fee¹.
3. Apply for the building permit through Los Angeles County Building and Safety².
4. If the lot is in a special flood hazard area, obtain a development permit from the Floodplain Administrator (the City Engineer) before construction begins⁸.
5. If a private sewage system is involved, get approval from the local health officer and confirm the process with the county's Onsite Wastewater Treatment Program⁶³.
6. Build to the California Building Standards Code that applies to your permit application date¹⁸.

What stays with Los Angeles County, and what to check before you buy

Outside city limits, Los Angeles County's Planning and Public Works offices handle unincorporated land; see the Los Angeles County page for those rules. Inside the city, building permits still come from the county under contract, and septic plans go through the county's health program²³.

Before buying, check flood hazard status, since new residential construction in a flood hazard area must have its lowest floor elevated at least one foot above base flood elevation⁸. Also budget for taxes: Los Angeles County's effective property tax rate is 0.7%¹⁹, and the typical home value is about $888,426²⁰.

Watch-outs

• A Westlake Village mailing address does not guarantee the property is inside the city, so verify the parcel with the Planning Department before using any rule here¹.
• We could not confirm which agency is the 'local health officer' for septic approval inside the city; ask the county's Onsite Wastewater Treatment Program⁶³.
• We could not confirm R-1 minimum lot size, setbacks, height, home size or permit fees for the city; ask the Planning Department¹.

Sources

1. City of Westlake Village Planning Department (wlv.org)
2. L.A. County Building and Safety (Calabasas permit office, serving Westlake Village) (wlv.org)
3. LA County Department of Public Health, Environmental Health – Onsite Wastewater Treatment Program (admin.publichealth.lacounty.gov)
4. Westlake Village Code 9.14.070 ADU Development Standards (Westlake Village), quoted and re-checked
5. Westlake Village Code 9.14.090 Two Units in Single-Family Residential Zones (Westlake Village), quoted and re-checked
6. Westlake Village Code 9.14.070 ADU Development Standards (Westlake Village), quoted and re-checked
7. Westlake Village Code 9.14.070 ADU Development Standards (Westlake Village), quoted and re-checked
8. Westlake Village Code 8.5.030 Floodplain Administration (Westlake Village), quoted and re-checked
9. Los Angeles County Code Title 22: Planning and Zoning, quoted and re-checked
10. Westlake Village Code 9.14.080 ADU/JADU Review Process (Westlake Village), quoted and re-checked
11. Building Officials - Owner-Builder Overview, quoted and re-checked
12. Local Agency Management Program (LAMP), quoted and re-checked
13. Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems (OWTS Policy) (California statewide rule), quoted and re-checked
14. Westlake Village Code 9.14.080 ADU/JADU Review Process (Westlake Village), quoted and re-checked
15. Westlake Village Code 10.1.050 Urban Lot Splits (Westlake Village), quoted and re-checked
16. Westlake Village Code 9.14.080 ADU/JADU Review Process (Westlake Village), quoted and re-checked
17. FAQs - LA County Planning, quoted and re-checked
18. Approved Building Standards (California statewide rule), quoted and re-checked
19. Effective property tax rate: Bolthole Index county data
20. Typical home value (Zillow): 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.