ADU Builders & Home Addition Contractors in Los Angeles, CA
From the San Fernando Valley flats to the Westside hills, HomeAdd designs, permits, and builds ADUs, garage conversions, and home additions across the City of Los Angeles — headquartered in Woodland Hills.
Building ADUs and additions in Los Angeles
Los Angeles is the largest and most varied city in our service area. The flat postwar tracts of the San Fernando Valley offer deep rear yards and detached garages that suit ADUs and garage conversions. The hillside neighborhoods south of Ventura Boulevard and along the Santa Monica Mountains trade yard space for views, and shift the conversation toward grading, access, and fire-zone design. The basin and Westside add smaller lots, older housing stock, and some of the city's most valuable square footage.
Every address inside the City of Los Angeles is permitted by the Los Angeles Department of Building and Safety (LADBS), with zoning administered by Los Angeles City Planning — never by LA County. On top of the base zoning, individual parcels can carry hillside ordinance rules, specific plans, historic preservation overlays (HPOZs), coastal zone requirements near Pacific Palisades, and Very High Fire Hazard Severity Zone designations. We confirm exactly which of those apply to your address during feasibility, before design starts.
Typical Los Angeles projects: a 600–1,200 sq ft detached ADU in a Valley rear yard, a garage conversion where the driveway already reaches the back of the lot, an above-garage unit where yard space is precious, or a second-story addition on a ranch house that has run out of bedrooms. We also maintain dedicated pages for the LA neighborhoods we work in most — Woodland Hills, Encino, Sherman Oaks, Tarzana, Northridge, Studio City, and more.
City of Los Angeles permitting — LADBS & LA City Planning
If your parcel is inside the City of Los Angeles, one department reviews your building permit: LADBS. Zoning, setbacks, and overlays are administered by Los Angeles City Planning. LA County departments, county fees, and county submittal portals do not apply — a distinction that matters, because much of the advice online mixes city and county rules together.
Two City of LA programs are worth knowing about. The LADBS Standard Plan Program offers pre-reviewed ADU plan sets that can shorten plan check when a plan genuinely fits the lot. And California's 60-day ADU review clock applies to every city department, including LADBS. We identify the zoning designation, hillside status, fire-zone status, and correct submittal path for your exact address before design begins.
- 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 Los Angeles projects
- Hillside ordinance areas south of Ventura Boulevard and along the Santa Monica Mountains — grading, retaining, and access shape the design.
- Very High Fire Hazard Severity Zone parcels — materials, defensible space, and fire access affect both ADUs and additions.
- Coastal zone requirements near Pacific Palisades, which add a separate layer of review.
- Historic Preservation Overlay Zones (HPOZs) and specific plans that can affect exterior changes and additions.
- Older postwar homes with 100-amp electrical services that often need a panel upgrade for a new unit.
- Mature protected trees (including oaks) that affect siting and foundation choices.
- Deep Valley rear yards that suit detached ADUs of 600–1,200 sq ft, versus tighter basin lots where conversions and additions often pencil better.
What we build most often in Los Angeles
Los Angeles service deep dives
Los Angeles neighborhoods we cover
Neighborhoods listed describe our coverage area, not project addresses.
Budgeting a Los Angeles ADU or addition
Every number we publish is a preliminary planning range, not a quote. Cost in Los Angeles 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.
Los Angeles ADU questions, answered
Who issues ADU permits in the City of Los Angeles?+
LADBS — the Los Angeles Department of Building and Safety. Every parcel inside the City of Los Angeles goes through LADBS for plan check and building permits, with zoning administered by Los Angeles City Planning. LA County departments do not review City of LA addresses.
Do LADBS Standard Plans make ADU permitting faster in Los Angeles?+
They can. The LADBS Standard Plan Program offers pre-reviewed ADU designs, and when one genuinely fits your lot, plan check can be shorter. Fit is the key word — setbacks, fire access, and utility runs are site-specific. We check during feasibility whether a standard plan works for your address or a custom design serves you better.
Can I build an ADU on a hillside lot in Los Angeles?+
Often yes, but hillside parcels add design and review steps: grading and drainage, retaining walls, fire-access requirements, and sometimes geotechnical work. We confirm hillside status and fire-zone designation for the address during feasibility so the design accounts for it from day one.
How long does an ADU or addition take in Los Angeles?+
Timelines vary by scope, site conditions, and plan check load. Design and permitting typically run several months, and construction runs several months after permits are issued. Hillside, coastal, and HPOZ parcels generally add time. We give you a schedule specific to your project after feasibility rather than a generic promise.
Which parts of Los Angeles does HomeAdd cover?+
All of it, with the deepest coverage in the San Fernando Valley — Woodland Hills (our headquarters), Encino, Sherman Oaks, Tarzana, Northridge, Studio City, Van Nuys, Reseda, Canoga Park, West Hills, and Granada Hills — and regular work across the Westside and basin, including Pacific Palisades, Brentwood, and West LA.
Nearby areas we build in
Further reading
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Everything you need to plan an ADU, garage conversion, or addition on a Los Angeles property.