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 the Baseline Hillside Ordinance kill my ADU?

Almost never. State ADU law overrides local FAR limits up to 800 sqft, and many hillside lots can fit a full 1,200 sqft attached ADU even under BHO.

How much does hillside geotech add?

Plan on $8–25k for the report itself. The downstream cost — caissons, retaining walls, deeper foundations — is where the real budget impact lives.

Hills & Canyons Detached ADU.

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

Hill parcels add the Baseline Hillside Ordinance, geotech, and (along the ridgeline) the Mulholland Scenic Parkway Specific Plan to every permit package. The ADU itself is still ministerial, but plan-check takes longer because the structural, grading, and haul-route sheets are heavier than a flat-lot project.

Hills & Canyons cost band — 2026

$320K – $520K all-in

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

Hills & Canyons permit clock

12–18 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.

BHO caps height to ~33 ft and limits grading cuts based on lot slope.
Soils / geotech report required on any slope >10%.
Hillside Construction Regulation permits gate haul-route hours and truck size.
Beverly Hills + Bel-Air HOA / R1 design review runs parallel to building permit.

What moves the Hills & Canyons number.

Slope-driven foundation work commonly $80–250k above flat-lot equivalent.
Crane / pump days run 2–4× a Valley job — narrow streets and switchbacks.
Caissons on steep slopes can hit $1,500–4,000 per linear foot of depth.
Beverly Hills design review pushes cladding budgets up sharply.

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 the Baseline Hillside Ordinance kill my ADU?: Almost never. State ADU law overrides local FAR limits up to 800 sqft, and many hillside lots can fit a full 1,200 sqft attached ADU even under BHO.
How much does hillside geotech add?: Plan on $8–25k for the report itself. The downstream cost — caissons, retaining walls, deeper foundations — is where the real budget impact lives.

More we build in Hills & Canyons.

Detached ADU in nearby LA areas.

Got a Hills & Canyons project in mind?

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

Start a Hills & Canyons project →