Junior ADUs (JADUs) in San Diego
A junior ADU turns space you already have, like a bedroom, a wing of the house or an attached garage, into a separate small home with its own entrance. It’s the lowest-cost way to add a legal second unit.
JADUs from $50,000. Every project is scoped and quoted individually. City permits and fees are billed separately.
What counts as a JADU
- Up to 500 square feet, created within your existing home. Under state law, an attached garage counts as part of the home.
- Its own entrance, separate from the main entrance.
- An efficiency kitchen: a cooking facility with appliances, a food prep counter and storage cabinets.
- Its own bathroom, or a bathroom shared with the main house.
- One JADU per single-family lot, and it can sit alongside a regular ADU.
As of January 2026, state law only requires the owner to live on the property if the JADU shares a bathroom with the main house. Local rules can add detail, so we confirm exactly what applies to your home during feasibility.
What a JADU costs
from $50,000
The biggest variables are whether the JADU gets its own bathroom, how far plumbing has to run, and whether a garage slab needs work. A bedroom conversion with a shared bath sits at the low end; a garage conversion with a full bath sits higher. An attached garage turned into a unit of up to 500 square feet can be a JADU. A larger conversion, or a detached garage, is priced as a garage conversion ADU, from $80,000.
How long it takes
Because it’s inside the existing structure, a JADU is usually the fastest legal unit to permit and build. We give you a written schedule after feasibility.
JADU, garage conversion or full ADU?
JADU (up to 500 sq ft, inside the home)
A junior ADU carved out of existing space, with its own entrance and an efficiency kitchen.
Garage conversion ADU
Turning an attached or detached garage into a legal living unit.
Attached ADU
A new unit built onto the existing house.
Detached ADU
A standalone backyard home, from foundation to finish.
Every project is scoped and quoted individually. City permits and fees are billed separately.
JADU questions
Why would I build a JADU instead of an ADU?
Cost and speed. A JADU uses structure you already own, so there’s no new foundation or roof. If you need a private space for a family member or a rental without building a new structure, it’s the most efficient route.
Can I rent out a JADU?
Yes, as a longer-term rental. State law requires any rental of a JADU to be for more than 30 days, so it can’t be used as a short-term or vacation rental. If the JADU shares a bathroom with the main house, the owner also has to live in the house or in the JADU.
Do I need parking for a JADU?
Generally no additional parking is required. We confirm the specifics for your lot during feasibility.
Find out if your home can fit a JADU
Send us a few details about the project and we’ll set up a visit to look at the space.
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