California State Regulations
California's state regulations for Accessory Dwelling Units (ADUs) are designed to be flexible, allowing cities to adapt and adjust these rules to meet their local needs. These regulations outline the requirements for both ADUs and Junior ADUs, including guidelines on the number of units allowed, size limitations, setbacks, and additional system requirements. Explore the specific state regulations below to understand how you can effectively plan and build your ADU in compliance with California's guideline.
ADU/JADU Quantity:
A) 1 ADU and 1 JADU per lot: You can have one ADU and one JADU within a single-family dwelling or accessory structure on your property. They must meet specific requirements like having exterior access and following fire safety setbacks.
B) Detached new construction ADU: You can build one detached ADU that may be required to meet a maximum size of 800 square feet and a height limit of 16 feet. ADU should not exceed four-foot side and rear yard setbacks. This ADU can also be combined with a JADU on the same lot.
C) ADUs in multifamily structures: In parts of multifamily buildings not used for living space, you can add multiple ADUs. Local agencies must allow at least one of these types of ADUs and up to 25 percent of the existing multifamily structures.
D) Up to 2 detached ADUs in multifamily dwellings: You can add up to two detached ADUs on a lot that already has multifamily dwellings. These ADUs must adhere to a height limit of 16 feet and four-foot rear and side yard setbacks.
E) Conversion of existing space: You can convert existing space within a single-family dwelling or accessory structure into an ADU without specific size limitations, height restrictions, setbacks, or other development standards.