ADU Builders & Home Addition Contractors in West Hills, CA
West Hills lots are larger than most of the Valley, which opens up full-size detached ADUs and substantial additions.
Building ADUs and additions in West Hills
West Hills sits at the far west edge of the San Fernando Valley, where lots get bigger and the terrain starts to rise toward the Simi Hills. That combination is good news for ADUs: many parcels have the rear-yard area for a full-size detached unit with genuine separation from the main house.
West Hills is part of the City of Los Angeles, so LADBS reviews permits and Los Angeles City Planning administers zoning. The western and northern edges include Very High Fire Hazard Severity Zone areas, where materials, defensible space, and fire-apparatus access shape the design.
Typical West Hills work: 800–1,200 sq ft detached ADUs, primary-suite and family-room additions on large single-story homes, and second-story additions where owners want more space while keeping the yard.
West Hills permitting — LADBS and City Planning
West Hills is a neighborhood of the City of Los Angeles, so ADU and addition permits are reviewed by LADBS with zoning administered by Los Angeles City Planning — not by Los Angeles County. That single fact changes the entire permit path, because County rules, fees, and submittal portals do not apply here.
Practically, that means your project follows City of LA zoning code, City of LA plan check, and City of LA inspection scheduling. It also means LADBS Standard Plans are available, which can shorten review when a pre-approved plan actually fits the lot. We confirm the zoning designation, any specific plan or hillside overlay, and the correct submittal path for your exact address before design starts.
- Los Angeles Department of Building and Safety (LADBS) Plan check and building permits for every address inside the City of Los Angeles.
- Los Angeles City Planning Zoning, specific plans, hillside and overlay rules that shape what can be built on the lot.
- LADBS Standard Plan Program Pre-reviewed ADU plan sets that can shorten plan check for City of LA parcels when a plan fits the site.
- California HCD ADU Handbook State-level ADU baseline that every California city and county must permit at minimum.
Local rules, fees, and site conditions change and vary by parcel. Always confirm current requirements with the reviewing department for your address — this page is general information, not legal or code advice.
Site conditions that affect West Hills projects
- Larger lots that can support a full-size detached ADU with real separation.
- Very High Fire Hazard Severity Zone areas near the western hills.
- Slope and drainage on parcels backing to open space.
- Fire-apparatus access and turnaround requirements on longer driveways.
- Long utility runs on deep lots.
- Protected and mature trees affecting siting.
What we build most often in West Hills
West Hills service deep dives
West Hills neighborhoods we cover
Neighborhoods listed describe our coverage area, not project addresses.
Budgeting a West Hills ADU or addition
Every number we publish is a preliminary planning range, not a quote. Cost in West Hills moves with unit size, design complexity, site conditions, utility work, jurisdictional requirements, and finish level. Use our cost estimator to build a starting range, then we produce a detailed construction proposal after feasibility and design work is complete.
West Hills ADU questions, answered
Does the fire hazard zone stop me from building an ADU in West Hills?+
Generally no, but it changes the design. Fire-zone parcels typically involve ignition-resistant materials, defensible space planning, access requirements, and in some cases sprinklers. We confirm the designation for your address and design to it from the start.
Who issues the building permit?+
LADBS. West Hills is inside the City of Los Angeles, so LA County departments do not review the project.
Can a larger lot support more than one added unit?+
State law allows certain combinations, such as an ADU plus a junior ADU on a single-family lot, subject to local implementation. What your parcel supports depends on zoning, setbacks, and lot coverage, which we verify during feasibility.
Are additions or ADUs more common here?+
We see both. Larger West Hills homes often lead to primary-suite or family-room additions, while owners focused on rental income or family housing usually choose a detached ADU.
Nearby areas we build in
Further reading
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Everything you need to plan an ADU, garage conversion, or addition on a West Hills property.