New laws taking effect January 1, 2021 enable more homeowners to build ADUs and in many cases make obtaining permits much quicker and less expensive. ADUs are also called: granny flats, in-law units, backyard cottages, second dwelling units, etc.
Automatic Approval: Cities/counties must permit certain categories of ADUs without applying any local development standards if proposed on a single-family lot. ADUs eligible for this automatic approval include:
- An ADU or JADU (junior ADU) converted from existing space in the home or another structure (e.g. a garage), so long as the ADU has exterior access and setbacks sufficient for fire safety
- A new detached ADU under 800 sq ft in size, 16 feet in height, with 4-foot side/rear setbacks
- Both of the above options in combination, creating one internal JADU and one detached ADU
Reduced Costs for Developing ADUs
- ADU applications must be approved within 60 days, without a hearing or discretionary review
- For ADUs permitted by 2025, cities/counties cannot require the owner to live at the property
- No impact fees are required for ADUs under 750 sq ft; proportional fees apply to larger ADUs
- An ADU can be developed at the same time as a primary dwelling, under most of the same rules
- A city/county must delay code enforcement on an unpermitted ADU to allow it to be legalized
- Single-family HOAs must allow the development of ADUs, subject to reasonable standards
- Single-family homeowners can also develop JADUs – units under 500 sqft within a residence
Previously many cities restricted the construction of ADUs to single-family lots larger than 8,000 sq ft.
More details are provided on my ADU – Accessory Dwelling Unit web page .