Downey · Los Angeles County
ADU builder in Downey.
INVICTA designs, permits and builds detached ADUs and garage conversions in Downey — with the plans, fire review and construction handled by one team.
- Detached ADUs
- Garage conversions
- Pre-approved plans
- Multi-unit lots
Permits in Downey
What to know before you build in Downey.
- Updated rulesDowney’s ADU rules are in Municipal Code Section 9414, updated in June 2026.Source: Downey ADU information
- Pre-approved detached plansDowney offers pre-approved plans for detached ADUs.Source: Downey pre-approved ADU plans
- Online submittalADU plans are submitted electronically through the city’s Accela Citizen Access portal. Planning: (562) 904-7154.Source: Downey ADU information
Summarized from official sources as of October 2026. Rules change — your free feasibility report checks the current rules for your exact lot.
California ADU law
State law sets the floor.
Every California city, including Downey, has to follow these state rules.
See what applies to my lot- 3 unitsOn a single-family lot, state law allows a new detached ADU, a converted ADU and a junior ADU together. Source
- 800 sfCities must allow a detached ADU of at least 800 sf with 4 ft side and rear setbacks. Source
- No owner ruleCities can’t require you to live on the property to build or rent an ADU. Source
- 750 sfADUs of 750 sf or less can’t be charged impact fees. Source
- 15 daysThe city must tell you within 15 business days whether your application is complete. Source
What we build
One team, design to keys.
- Detached ADUsBackyard homes from studios to 2-story units.
- Garage conversionsTurn an unused garage into a rental or family suite.
- ADU over garageKeep the parking, add a home above it.
- Additions & remodelsPrimary suites, second stories, kitchens and baths.
Built by INVICTA
Recent projects near Downey.
Does Downey have pre-approved ADU plans?
Yes, for detached ADUs. We check whether a pre-approved plan fits your lot or a custom design gets you more.
Did Downey change its ADU rules?
Yes. Downey updated its ADU ordinance (Municipal Code Section 9414) in June 2026. Your feasibility report uses the current rules.
Can I add more than one ADU in Downey?
Often, yes. State law allows a detached ADU, a converted ADU and a junior ADU on many single-family lots, and more on multifamily lots.
Free feasibility report
What could your Downey lot build?
Send us your address. We’ll check your zoning, lot size, setbacks and utilities and send a written report on how many ADUs fit, what they’d cost and the path to permits — free.
- What you can buildHow many units, what size and where they fit on your lot
- Rules for your cityZoning, setbacks, height and state ADU law applied to your property
- Utilities & accessSewer, water, power and the path to the back of the lot
- Budget & rentA realistic cost range and what comparable units rent for
Request received.
Thanks — we’ll review your property and reach out with next steps.
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