JADU rules, made simple.
A Junior ADU can create a smaller living area inside a single-family home—but it is not simply a bedroom with a refrigerator.
What is a JADU?
A JADU contains no more than 500 square feet of interior livable space and stays entirely within a proposed or existing single-family residence. It may use space in an attached garage. It needs exterior access and must meet efficiency-kitchen rules. A bathroom may be private or, in some cases, shared with the main home.
JADU vs. ADU
| Question | JADU | ADU |
|---|---|---|
| Size | Maximum 500 sq. ft. | Varies by type and standards |
| Location | Inside a single-family residence | Detached, attached or converted |
| Bathroom | May be private or shared | Independent sanitation |
| Kitchen | Efficiency kitchen | Permanent cooking facilities |
Does the owner have to live there?
Under the 2026 rules, if the JADU shares sanitation facilities with the primary home, owner occupancy is required. If it has separate sanitation, state law does not require owner occupancy, subject to limited exceptions and local application.
Can a JADU be rented?
A JADU cannot be used as a short-term rental under the 2026 state update. If rented, the term must be longer than 30 days. Other local rental rules may apply.
Feasibility checklist
- Is this a qualifying single-family property?
- Can the unit stay entirely inside the home or attached garage?
- Is there safe exterior access and emergency egress?
- Will sanitation be private or shared?
- Can plumbing, power and ventilation be added efficiently?
- How will the layout affect the main home?
Compare a JADU with a full ADU
The smallest plan is not always the least expensive or most useful.
Review the options with DG Builders