JADUs in San Diego
A Junior ADU lets you add a self-contained suite for family, guests, or rental — carved out of your existing home, with the lowest possible cost and the fastest possible permit path.
What Is a JADU?
A Junior Accessory Dwelling Unit (JADU) is a self-contained living space carved out of an existing single-family home or attached garage. Maximum 500 square feet. Must include a sleeping area, an efficiency kitchen, and a separate exterior entrance.
The unique JADU advantage: you can share a bathroom with the primary residence, which means you don''t have to move plumbing stacks. That single allowance is what makes JADUs the lowest-cost path to a permitted second unit on most San Diego properties.
JADU vs. ADU vs. Garage Conversion
Three paths, three different rule sets. We help you choose the right one.
JADU
Up to 500 sq ft. Inside the existing home or attached garage. Efficiency kitchen. Optional shared bathroom. Owner-occupancy required. Lowest cost. Best for in-law suites and aging-in-place.
Full ADU
Up to 1,200 sq ft (or larger under SD ADU Bonus Program). Detached or attached. Full kitchen, full bath. No owner-occupancy required for new units. Best for long-term rental income or true second-home use.
Garage Conversion
Convert an existing detached or attached garage into a JADU or ADU. The fastest path to permitted square footage when you already have a structure to work with.
How Lumina Designs a JADU That Actually Lives Well
500 square feet is small. Done badly, it feels small. Done well, it can house an aging parent or adult child with full dignity — their own entrance, their own kitchen corner, their own quiet zone, their own daylight.
We approach JADUs the way good architects approach studio apartments: tall ceilings where possible, generous windows, real storage, an efficiency kitchen that doesn''t look like a hotel kitchenette, and acoustic separation from the rest of the home.
Our Process
Five clear stages.
Walk-Through
On-site assessment of where the JADU can go and which rule set fits your home.
Design
Floor plan, finish selections, and a fixed-scope construction proposal.
Permitting
JADU permits move quickly under streamlined state and local pathways.
Build
Demo, structural, MEP, and finish work, executed by Lumina's in-house team.
Move-In
Final inspection, certificate of occupancy, walkthrough, one-year warranty.
Cost & Timeline
JADUs Lumina builds in San Diego typically run $90,000 to $180,000 turnkey. Cost is driven by whether you keep the bath shared (lower) or add a separate bath, plus the level of finish you choose.
Timeline is typically two to four months on the build, plus four to eight weeks of design and permitting. JADUs benefit from streamlined state-mandated permit timelines and reduced impact fees.
Frequently Asked Questions
Do I have to live in the main house if I build a JADU?
Yes — owner-occupancy is currently required for JADUs. Either you must live in the primary residence or in the JADU itself. This is the main rule that distinguishes a JADU from a standard ADU.
Can I have a JADU and a separate ADU on the same lot?
On most San Diego single-family lots, yes — one JADU plus one ADU is allowed by right under current state law. This is one of the most powerful (and underused) levers for adding density and rental income to a single property.
What counts as an efficiency kitchen?
At minimum: a sink with running water, a small refrigerator, and a cooking appliance. The cooking appliance must be permitted but doesn''t require a separate gas line — a 220V cooktop or even a high-quality countertop induction unit can satisfy code in many jurisdictions. We confirm specifics during design.
Is a shared bathroom really legal?
Yes. JADUs are explicitly permitted to share a bathroom with the primary residence — the JADU just needs a separate exterior entrance and the efficiency kitchen. This rule is unique to JADUs and is what enables the lowest-cost path to a permitted unit.
Are JADU impact fees waived?
Most school, water, and sewer impact fees are waived for JADUs under current state and San Diego rules. Combined with the no-foundation, no-utility-hookup advantage of building inside an existing home, this is what makes JADUs so cost-effective.
What Multigenerational Clients Say
Real reviews from San Diego homeowners who built a JADU for family, in-laws, or long-term rental.
Find Out If a JADU Is Right For Your Home
A free walk-through is the fastest way to know if your home qualifies and what your specific JADU would actually cost.
