Junior accessory dwelling units create separate, small in-law suites within an existing single-family house. Permitting requirements are typically lighter than for attached/detached ADUs (e.g., fewer restrictions on sprinklers, parking) and include allowance for a small kitchen.
Benefits & Problems Addressed
More units with fewer regulatory hurdles: Homeowners can create suites within their homes inexpensively and quickly. JADU programs seek to eliminate or lessen requirements that form the biggest, most expensive hurdles: sprinklers and parking.
Affordability: JADUs offer affordability for renters (increase in supply) and for homeowners.
Flexibility: Units can be constructued and dissembled quickly.
Tips & Techniques
How to get started: Read your city or county's zoning code to determine the requirements for accessory dwelling units. Document the restrictions. California has adopted state legislation defining the parameters & process for JADUs.
Regulatory considerations: With Junior ADUs, the zoning and deed remains the same. In general, JADUs are allowed in all single family, residential zoning categories.
Comparison of JADUs and ADUs: Though not currently in widespread use, California is leading the way on junior ADUs:
| ADU | JADU |
| Located within main house, attached or detached cottage | Located wholly within the main structure |
| Off-street parking required | Parking not required |
| Full kitchen | Small kitchen |
| Separate entrance | Separate or within home |
| Permit fees | Reduced or waived permit fees |
| Fire proofing & sprinklers | Smoke detectors |
Smaller kitchen: California's law governs kitchen size by plumbing (a wet-bar type kitchen with a 1.5 inch drain pipe limit and limits on stoves/overs to standard electrical service (110v). This means a homeowner cannot install natural gas or heavier electric service for a large stove.
Hot Buttons: The relaxed requirements raise common concerns with neighbors on parking and additional rental units. California's action on the state level overrides local authority.
Resources
Junior Accessory Dwelling Units, AccessoryDwelling.org
California Legislation CA AB2406
Image: Novato California