Short answer: yes. California ADU law allows several types of accessory dwelling units on any multi-family property. The two types are detached ADUs and conversion ADUs.

A detached ADU is a free-standing building separate from the main multi-family building. A conversion ADU turns existing non-livable space — in the main building or an accessory structure — into a home. Typical conversion areas are storage rooms, recreation rooms, garages and carports.

Why add ADUs to a multi-family property?

Property owners tend to think of ADUs as an option for single-family homeowners. That’s the most common application, but not the only one. Adding detached ADUs, or converting an underused garage or storage area, increases overall property value and adds rental income — a great way to add units and maximize a property’s rental potential.

How many ADUs can I build?

It depends on what already exists on the property. Typically, two detached ADUs are allowed on a property with a multi-family building. The number of conversion ADUs depends on the existing unit count: at least one is always allowed, up to 25% of the existing units.

Are there special regulations for multi-family ADUs?

Detached ADUs on a multi-family property may be limited to 16 feet in height, though some cities allow up to 25 feet, which permits a two-story building. Minimum setbacks are 4 feet at the rear and 4 feet at the sides. Maximum size varies by city, but owners can always build an ADU of at least 800 sq ft.

Conversion ADUs inside the main building are treated as part of that building and follow its requirements. For example, if the main building has fire sprinklers, an ADU created within it will need them too.

Does parking need to be replaced or provided?

ADUs created by converting a carport or garage don’t have to replace the lost parking. New detached ADUs don’t need on-site parking if the property is within half a mile of public transit, including a bus stop.

Conclusion

Adding ADUs to a multi-family property can increase rental income and add significant value. Seen another way, ADUs are a smart investment in a property you already own — the return on cost can be very attractive. Learn more about multi-family ADUs, or schedule a free property analysis to see what’s possible on yours.