$45–$70/sqft pressure-treated; $80–$110 composite or IPE.

Do I need a permit for a low patio?

No if under 30in above grade and detached.

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 Decks & Patios.

LA decks — backyard ground-level, raised, rooftop. Composite (Trex, TimberTech), redwood, and IPE. Engineer + LADBS permit on raised or attached.

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

$45 – $110 / sqft

Pressure-treated bottom; composite + steel top.

South Bay permit clock

8–14 weeks ministerial

2–4 weeks depending on size + height.

Scope — start to keys.

Engineering + permit
Footings + posts
Framing + ledger
Decking + railing
Final inspection

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.

LA deck cost?: $45–$70/sqft pressure-treated; $80–$110 composite or IPE.
Do I need a permit for a low patio?: No if under 30in above grade and detached.
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.

Decks & Patios in nearby LA areas.

Got a South Bay project in mind?

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

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