Who issues your building permit in the west Valley and Conejo Valley
PUBLISHED SEPTEMBER 5, 2026 · REVIEWED BY MILAD KAZEMI
Which agency reviews your permit depends on whether your address is inside an incorporated city or inside the City of Los Angeles. Agoura Hills, Calabasas, Westlake Village, Hidden Hills, Malibu and Thousand Oaks each run their own building department. Woodland Hills, Tarzana, Encino, Sherman Oaks, Brentwood and Bel Air are City of Los Angeles and go through LADBS.
Jurisdiction boundaries and department references verified as of 10 September 2026.
The boundary matters more than the distance
Agoura Hills and Woodland Hills are fifteen minutes apart on the 101. They are permitted by completely different agencies, under different local amendments, with different submittal requirements and different review queues.
A homeowner who reads a Los Angeles ADU guide and applies it to a Calabasas property will get some of it right and some of it expensively wrong.
Here is the map for the area we work in.
Incorporated cities — their own building department
Agoura Hills. Reviews and issues its own permits. Much of the city is hillside and in a very high fire hazard severity zone, so grading, drainage and ignition-resistant construction requirements are usually in play from the first sketch.
Calabasas. Own department, with scenic corridor and hillside standards across much of the city. Height and ridgeline visibility are frequently the binding constraint. Many parcels also sit inside a homeowners association with its own architectural review running in parallel.
Westlake Village. Own department. A large share of residential parcels are inside planned developments, so association review is generally part of the timeline.
Hidden Hills. A small gated city with an architectural review process ahead of building permit issue, plus standards on materials, fencing and equestrian access that shape the site plan.
Malibu. Own building department, plus Coastal Development Permit review for almost the entire city, assessed against the certified Local Coastal Program. Add onsite wastewater treatment review where there is no sewer, geotechnical review on bluff and hillside parcels, and fire-zone construction requirements.
Thousand Oaks. Ventura County, not Los Angeles County — a different set of county-level processes and different local amendments, a few minutes west of Agoura Hills.
Beverly Hills. Own department, with design review applying to many single-family projects and a separate set of hillside standards north of Sunset.
City of Los Angeles — LADBS
Woodland Hills, Tarzana, Encino, Sherman Oaks, North Hollywood, Brentwood, Bel Air, Pacific Palisades and Venice are all City of Los Angeles addresses. Permits go through LADBS, and city-wide ordinances apply rather than county ones.
Three things change what is allowed on an LA parcel more than anything else:
- The zone and the community plan, which set the base rules for the lot
- Hillside status, which brings in the Baseline Hillside Ordinance and its limits on floor area and grading by lot slope
- Overlays and specific plans, which can tighten height, massing and materials well beyond the base zone
ZIMAS shows all three for any LA address, free, in about two minutes. It is the first thing worth looking at for any project inside the city.
What this means for a project
Two practical consequences.
Do not price a project from a general rule. “You can build an ADU up to X square feet” is a statement about a parcel, not about California. The jurisdiction, the zone, the existing floor area and the setbacks all have to be read before a number means anything.
Ask whoever you hire which jurisdictions they file in. A firm that submits in Agoura Hills, Calabasas and through LADBS regularly knows what each of those plan checkers asks for. That knowledge is worth a correction cycle, and a correction cycle is worth weeks.
Sources
Rules change. Confirm anything you are relying on against the agency directly.
Questions we get asked
- Does it matter which agency reviews my project?
- Yes. Each jurisdiction adopts its own amendments to the state code, runs its own plan-check process and applies its own local overlays. Two identical houses on either side of a city boundary can face materially different requirements, review timelines and submittal formats.
- How do I find out which jurisdiction my property is in?
- A parcel search on the county assessor's site will tell you the city, and for City of Los Angeles addresses, ZIMAS gives the zone, the community plan, hillside status and any overlay that applies. Both are free and take a few minutes.
- Do I need a separate permit if my property is in the Coastal Zone?
- Generally yes — a Coastal Development Permit in addition to the building permit, reviewed against the certified Local Coastal Program. In Malibu that covers almost the whole city. Parts of Pacific Palisades are also inside the Coastal Zone.
Send us the address.
Tell us the property and roughly what you want to build. We come back with what the zoning allows, the likely permit path, and a fixed fee for the first phase.