What state law guarantees you
Since 2020, California requires cities to approve Accessory Dwelling Units ministerially — staff review against fixed standards, not discretionary hearings. A detached ADU of up to 800 square feet with four-foot side and rear setbacks generally cannot be denied on size alone. Owner-occupancy requirements have been narrowed by the legislature, and replacement parking cannot be demanded when a garage is converted close to the lot lines.
The 60-day clock
Once you submit a complete ADU plan set, the city has 90 days under the original law — tightened in practice to 60 days under later amendments — to approve or send a single consolidated list of corrections. That clock is why the quality of your first submittal matters: an incomplete package resets everything. Our office prepares ADU plan sets to pass the first review.
What your city can still require
Setbacks, height limits, fire separation, and utility connection standards still apply, and some cities add objective design standards. Hillside and very-high-fire zones (Tarzana and Woodland Hills slopes, Bell Canyon, Topanga) add fire-department review. None of these are discretionary once your plans comply — but they must be engineered in from the start.
Garage conversion specifics
A garage-to-ADU conversion keeps the existing slab and structure and adds what livability demands: insulation, a kitchenette, a bathroom, egress windows, HVAC, and often a separate electrical panel. The state protects these conversions precisely because they're the cheapest housing to create — and because they rarely change the home's street appearance.
Where to verify your parcel
Rules change. Check your city's ADU ordinance page (LA City Planning for most Valley addresses; Burbank, Glendale, Simi Valley, and Santa Clarita run their own), or ask us — we verify your parcel's setbacks, zoning, and utility capacity during the free site visit before you spend anything on plans.
Common ADU myths that cost homeowners money
Myth one: an ADU needs its own driveway — state law has largely abolished replacement-parking demands, especially near transit and for conversions. Myth two: utility upgrades always break the budget; many conversions run fine on a sub-panel and the existing service. Myth three: ADUs are only for young renters — in practice they house parents, adult children, and caregivers. Every myth has a permit-shaped price tag when believed late, which is why the feasibility visit checks facts before designs are drawn.
Use this before you sign anything
The point of a guide like this is to make your first contractor conversation a sharper one. You should be able to ask which permit path applies, what sequence the work follows, and what assumptions the price rests on — and get a straight answer instead of a sales one. Bring this checklist to any estimate, ours or a competitor’s, and compare the answers rather than the totals. Where your parcel, jurisdiction, or house differs from the general case, the guide says so rather than pretending one rule fits every lot; that is exactly when a free site visit beats another paragraph of reading. Ofir Construction Inc. has run these projects from the same Winnetka shop for twenty years, and if your situation sits outside what is written here, call (747) 203-9716 or email us — we will walk your property at no charge anywhere in our service area.
Common questions
Do I need an architect for an ADU?
Someone must prepare code-compliant drawings; for standard conversions, an experienced design-build contractor working with a draftsperson or engineer is usually enough. We handle ADU design in-house.
Can I build an ADU and rent both homes?
In most cases yes — state law has sharply limited owner-occupancy requirements, but rules differ by city and change often. We confirm the current rule for your parcel before design.
Can I build two ADUs on one lot?
On many lots, yes — state law allows a detached ADU plus a junior ADU inside the primary home, and some jurisdictions allow more. We confirm your parcel's capacity during the free feasibility visit, including setbacks and utility capacity.
How long does the whole ADU process take?
Design and permitting commonly run two to three months on the ministerial path; construction eight to sixteen weeks depending on size and whether it's a conversion or detached build. The estimate includes a dated calendar for both stages.
Related guides and services
- Room Addition, ADU, or Garage Conversion? — Additions, ADUs, and garage conversions compared on cost drivers, permits, and use cases —…
- Who Issues Your Building Permit in the Valley — LADBS, LA County, Ventura County, or an independent city hall — which office reviews your …
- ADU and Garage Conversions — permitted, rentable units with design and inspections handled in-house.
- General contractor in Winnetka — our home city
- General contractor in Reseda
Questions about your own project?
Guides are general — your parcel, your permit office, and your house have specifics. Call Ofir Construction Inc. at (747) 203-9716 or email OfirConstruction@gmail.com and we'll walk your property free of charge anywhere in our service area. Licensed, CSLB #1036242 — verify us at cslb.ca.gov.