Am I allowed to build an ADU? How many?

In almost all cases, yes! ADUs and JADUs are allowed in any single-family or multi-family zone. If residential buildings are allowed, ADUs are almost always allowed too (with limited exceptions for safety, traffic, and water availability).

State law allows a single-family property to have a JADU, and either an internal conversion or attached ADU or a detached ADU. Some places allow for more. Multifamily properties ­– like duplexes, triplexes, and apartment buildings – can have two detached ADUs or up to 25 percent of the number of units, depending on your property. Talk to your local planning staff for more information if interested in building ADUs on a multifamily property. Developers building new homes or multi-family housing can often include ADUs at the same time – confirm with planning staff.