How much does a detached ADU cost in LA in 2026?

$320K–$520K all-in for 600–1,000 sqft. Access, panel, and finish move the number.

Does LA require parking for a new detached ADU?

No within ½ mile of transit — covers most of LA County.

Does state ADU law apply in Ventura County?

Yes — every city in the county follows the state floor. Ministerial 60-day review, one detached ADU + one JADU per single-family lot.

Do I need a Coastal Development Permit in Ventura?

Only if the parcel is inside the Coastal Zone — generally the Ventura waterfront and Oxnard's coastal strip. Most inland parcels do not.

Ventura County Detached ADU.

Detached ADUs across Greater LA — own walls, roof, kitchen, bath, address. We handle LADBS submittal slab to certificate of occupancy.

Ventura County permits run cleanly under state ADU law. Each city (Oxnard, Camarillo, Thousand Oaks, Ventura) has its own building department, but all hold ministerial review at 60 days from a complete submittal. The variables are the Coastal Zone (waterfront parcels) and Very High Fire Hazard Zones along the foothills.

Ventura County cost band — 2026

$320K – $520K all-in

Lot access, panel upgrade, and finish drive the band.

Ventura County permit clock

6–10 weeks ministerial

3–5 months for design + LADBS permit, then 4–6 months on-site.

Scope — start to keys.

Site walk + zoning check
Full plan set + Title 24
LADBS permit
Foundation to finishes
CofO + warranty

What changes about the permit here.

State ADU law guarantees ministerial review on every single-family lot in the county.
Coastal Development Permit may be required on Ventura / Oxnard waterfront parcels.
VHFHSZ areas require Chapter 7A ignition-resistant exterior assemblies.
Thousand Oaks and Conejo Valley HOAs commonly add a parallel architectural review.

What moves the Ventura County number.

Lower labor cost than LA city — typically 8–12% below LADBS-area equivalents.
VHFHSZ Chapter 7A on Conejo Valley / Ventura backcountry parcels adds $18–35k.
Coastal Zone CDP on Ventura / Oxnard waterfront adds $15–35k in soft costs.
HOA architectural review (Thousand Oaks) is fee-light but schedule-heavy.

In short.

How much does a detached ADU cost in LA in 2026?: $320K–$520K all-in for 600–1,000 sqft. Access, panel, and finish move the number.
Does LA require parking for a new detached ADU?: No within ½ mile of transit — covers most of LA County.
Does state ADU law apply in Ventura County?: Yes — every city in the county follows the state floor. Ministerial 60-day review, one detached ADU + one JADU per single-family lot.
Do I need a Coastal Development Permit in Ventura?: Only if the parcel is inside the Coastal Zone — generally the Ventura waterfront and Oxnard's coastal strip. Most inland parcels do not.

More we build in Ventura County.

Detached ADU in nearby LA areas.

Got a Ventura County project in mind?

Send us the address and we’ll pull Ventura County zoning, setbacks, and detached adu feasibility before you spend on drawings.

Start a Ventura County project →