Junior ADUs (JADUs) in Orange County: The Complete Guide
A JADU is a compact unit (up to 500 sq ft) carved from your existing home — the lowest-cost path to a legal rental or in-law space.
A junior ADU is a small, self-contained unit created within your home’s existing walls — up to 500 sq ft, with its own entrance. It’s the lowest-cost way into a legal second unit. Here’s how it differs from a full ADU, what it costs, and the rules.
Junior ADU (JADU) construction in Orange County
A junior ADU (JADU) is a unit of 500 sq ft or less created within the walls of an existing single-family home. L Square handles JADU construction end-to-end in Orange County — design, the required interior connection and efficiency kitchen, permitting and the build — under one contract (CSLB #1095476). Because it reuses existing space, a JADU is often the lowest-cost path to a legal second unit. For a larger family unit, compare a JADU with a full in-law suite or a granny flat.
JADU vs ADU
A JADU is up to 500 sq ft and built within your home’s existing footprint, with its own entrance and an efficiency or shared kitchen. Unlike a full ADU, it carries an owner-occupancy requirement.
What it costs & who it suits
Because it reuses existing space, a JADU is typically the lowest-cost path to a legal unit — a good fit for a family suite or an affordable rental.
Permits & requirements
California’s JADU rules cover size, the kitchen, owner-occupancy and a recorded deed restriction. We handle the submittal and approvals.
Why build with L Square
Design, permits and construction under one roof. L Square is a licensed Orange County design-build team (CSLB #1095476). One contract covers architecture, engineering, city approvals and our own build crews — so your ADU moves on a fixed schedule from first drawing to final inspection, across Orange County and Los Angeles.
- 01 · Architect-grade design
- Every unit is drawn around your lot, light and privacy.
- 02 · Permit-ready, OC-savvy
- We know each city’s ADU rules and clear the approvals for you.
- 03 · Built once, built right
- Our own crews deliver on a fixed schedule, foundation to finishes.
Licensed · Insured · Bonded · CSLB #1095476 · Orange County & Los Angeles
Frequently asked questions
What’s the difference between a JADU and an ADU?
How big can a JADU be?
Do I have to live on the property?
Can I have both a JADU and an ADU?
What does a JADU cost?
Building an ADU in your Orange County city
ADU rules vary by city — we handle the specifics for your address. Statewide, California allows ADUs up to about 1,200 sq ft with 4-ft side and rear setbacks (CA HCD); your city may add its own details. For the statewide rules, see the CA HCD ADU Handbook.
Related guides & articles
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