How much does an ADU cost in Los Angeles in 2026?

Most detached LA ADUs land between $300K and $500K all-in. Garage conversions typically run $160K–$260K. We hand over a one-page feasibility note with a real number before any contract.

Do you handle LADBS permits?

Yes — full plan set, structural calcs, Title 24 energy compliance, and the LADBS back-and-forth so the homeowner only signs at the milestones.

Can I build a full-size 1,200 sqft ADU in Manhattan Beach?

MBMC §10.24 caps detached ADUs below state max in some lot sizes. We size the unit against the local ordinance during the feasibility walk.

Do I need a Coastal Development Permit in Hermosa?

Most of Hermosa Beach sits inside the Coastal Zone. A CDP is typically required unless the project qualifies for a categorical exclusion.

South Bay ADU Builder.

We design, permit, and build accessory dwelling units across Greater Los Angeles — detached backyard ADUs, attached additions, garage conversions, and JADUs. One team, one number to call, from the first feasibility walk through the final LADBS inspection.

South Bay permits hinge on which beach city you're in. Manhattan, Hermosa, and Redondo each enforce a local ADU ordinance that's stricter than LA city's, capping detached unit size and adding parking rules in some sub-areas. Coastal Zone status and Palos Verdes geotech are the biggest schedule variables.

South Bay cost band — 2026

$500 – $700 / sqft installed

Lot access, slab condition, panel upgrade, and finish level move the number most. Pre-approved plans trim 5–10%.

South Bay permit clock

8–14 weeks ministerial

Plan on 3–5 months for design + LADBS permit, then 4–6 months on-site for an 800–1,000 sqft detached ADU.

Scope — start to keys.

Site walk, feasibility note, and zoning / LAR1 / RD overlay check
Full architectural plan set, structural, MEP, Title 24 energy
LADBS or local-city permit submittal and back-and-forth
Foundation, framing, MEP rough, finishes, landscape tie-in
Final inspection, certificate of occupancy, and warranty

What changes about the permit here.

Manhattan Beach: ADU ordinance MBMC §10.24 — local design review for street-facing facades.
Hermosa Beach: tight side-yard setbacks on legacy walk-street lots.
Coastal Zone parcels (most of MB / HB) require a Coastal Development Permit.
Palos Verdes Peninsula: Portuguese Bend Landslide Complex overlays — geotech is mandatory, not optional.

What moves the South Bay number.

Highest detached cost in our service area — small lots, walk-street access, dump fees.
Coastal Development Permit consultant + biology costs commonly $20–60k on MB / HB lots.
Palos Verdes geotech (landslide complex) can add $35–100k in foundation engineering.
Local design review in Manhattan Beach often pushes architectural fees 25–40% higher.

In short.

How much does an ADU cost in Los Angeles in 2026?: Most detached LA ADUs land between $300K and $500K all-in. Garage conversions typically run $160K–$260K. We hand over a one-page feasibility note with a real number before any contract.
Do you handle LADBS permits?: Yes — full plan set, structural calcs, Title 24 energy compliance, and the LADBS back-and-forth so the homeowner only signs at the milestones.
Can I build an ADU in a hillside zone?: Usually yes, but Hillside Ordinance grading and access rules add design time. We've built in Silver Lake, Mt. Washington, Hollywood Hills, and the Palisades — geotech and shoring are part of the workflow.
Can I build a full-size 1,200 sqft ADU in Manhattan Beach?: MBMC §10.24 caps detached ADUs below state max in some lot sizes. We size the unit against the local ordinance during the feasibility walk.
Do I need a Coastal Development Permit in Hermosa?: Most of Hermosa Beach sits inside the Coastal Zone. A CDP is typically required unless the project qualifies for a categorical exclusion.

More we build in South Bay.

ADU Builder in nearby LA areas.

Got a South Bay project in mind?

Send us the address and we’ll pull South Bay zoning, setbacks, and adu builder feasibility before you spend on drawings.

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