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South Bay Detached ADU.

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

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

$320K – $520K all-in

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

South Bay permit clock

8–14 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.

  1. Manhattan Beach: ADU ordinance MBMC §10.24 — local design review for street-facing facades.
  2. Hermosa Beach: tight side-yard setbacks on legacy walk-street lots.
  3. Coastal Zone parcels (most of MB / HB) require a Coastal Development Permit.
  4. 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 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.
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.

Detached ADU in nearby LA areas.

Got a South Bay project in mind?

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

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