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Inland Empire 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.

The Inland Empire is the easiest jurisdiction we work in. Big lots, flat topography, and city building departments that already process high volumes of ADU permits mean a clean 60-day ministerial review is the norm. The only variables are the Very High Fire Hazard zones at the foothills and a few unincorporated pockets that run through Riverside or San Bernardino County directly.

Inland Empire cost band — 2026

$95K – $180K all-in

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

Inland Empire permit clock

5–9 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.

  1. Riverside, Corona, San Bernardino, Rancho Cucamonga: ministerial ADU portals, 5–8 weeks typical.
  2. VHFHSZ on north-facing foothill parcels — Chapter 7A exterior assemblies required.
  3. Unincorporated parcels routed through county building & safety — slower on inspection scheduling.
  4. SCE service drops are the most common schedule risk on detached new-build ADUs out here.

What moves the Inland Empire number.

  • Lowest cost in our service area — flat lots, big parcels, lower labor rates.
  • VHFHSZ Chapter 7A on foothill parcels adds $18–35k.
  • SCE service drop is the most common cost surprise — $4–18k depending on distance.
  • Big parcels mean detached ADUs over 1,000 sqft are common, scaling cost linearly.

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.
Why is the Inland Empire cheaper to build in?
Lower labor rates, flatter parcels, easier truck access, and lower dump fees. A detached new-build that costs $475/sqft on the Westside often lands at $375–425/sqft in Riverside.
Do I need to worry about fire-zone requirements?
Only if your parcel is on the foothill side — San Bernardino mountains, Banning Pass, San Jacinto north. Most of the valley floor is outside VHFHSZ.

More we build in Inland Empire.

JADU Builder in nearby LA areas.

Got a Inland Empire project in mind?

Send us the address and we’ll pull Inland Empire zoning, setbacks, and jadu builder feasibility before you spend on drawings.

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