What is a JADU and how is it different from an ADU?

A JADU (Junior ADU) is a unit up to 500 sqft built inside the footprint of an existing single-family house — usually a converted bedroom or garage. It requires owner-occupancy and is faster/cheaper to permit than a full ADU.

Can I have both a JADU and an ADU on my LA lot?

Yes — state law allows one JADU plus one ADU on most single-family lots in LA. The combination is often the best path for multi-generational living plus rental income.

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 JADU Builder.

A Junior ADU carves up to 500 sqft out of an existing single-family house, typically a converted bedroom or attached garage bay. It is the lightest-touch path to a permitted rental unit in LA — and the owner can keep occupying the main house. We handle the plan set, the LADBS permit, and the build.

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

$95K – $180K all-in

Existing plumbing wall proximity and whether the entrance already exists drive the band.

South Bay permit clock

8–14 weeks ministerial

Plan on 6–10 weeks for design + LADBS permit, then 8–12 weeks on-site.

Scope — start to keys.

Feasibility check — interior wall layout, plumbing access, exterior entry
Kitchenette, efficiency bath, and bedroom buildout
Separate exterior entrance, fire-rated demising wall if required
Owner-occupancy deed restriction and LADBS sign-off
Sub-panel, plumbing tie-in, mini-split HVAC

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.

What is a JADU and how is it different from an ADU?: A JADU (Junior ADU) is a unit up to 500 sqft built inside the footprint of an existing single-family house — usually a converted bedroom or garage. It requires owner-occupancy and is faster/cheaper to permit than a full ADU.
Can I have both a JADU and an ADU on my LA lot?: Yes — state law allows one JADU plus one ADU on most single-family lots in LA. The combination is often the best path for multi-generational living plus rental income.
How much does a JADU cost in Los Angeles?: Most LA JADUs land between $95K and $180K all-in. Existing plumbing proximity and whether the entrance already exists are the biggest swing factors.
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.

JADU 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 jadu builder feasibility before you spend on drawings.

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