How big can an ADU be?

There is a maximum size limit of 50% of the gross floor area of the primary dwelling unit, or 1,000 square feet, whichever is more restrictive. The maximum building coverage for the zone district also applies to the entire property.

As an exception to this limit, an ADU in a basement or second floor may exceed the above allowance if the first floor is the same area. For example, an ADU in a basement may be up to 1,200 square feet if the first floor is 1,200 square feet. 

If an ADU is part of a detached garage, the ADU square footage is counted separately from the footprint of the garage. For example, a detached garage of 800 square feet can potentially have an 800 square foot ADU above, and the ADU is only considered to be 800 square feet, not 1,600 square feet. 

Show All Answers

1. How tall can an ADU be?
2. How big can an ADU be?
3. Can I sell my ADU?
4. Can I rent my ADU and the main house?
5. Can I add an ADU to an existing garage?
6. Can I convert a portion of my house (eg basement or second floor) to an ADU?
7. Can I use my ADU as a short-term rental (STR)?
8. Can I convert my RV to an ADU?
9. Can I build a tiny home for an ADU?
10. I live in a duplex or attached townhome or condo, can I have an ADU?
11. Will an ADU require separate utilities?
12. Will an ADU require a separate address?
13. I have an existing dwelling unit that may qualify as an ADU, what if it's too big or too tall or too close to the property line?
14. I have an existing dwelling that may qualify as an ADU, why should I come to the City to get legal ADU status?
15. What if an existing living space can't meet building code to be an official ADU?
16. There are multiple existing ADUs on my property. Is this okay?
17. Will I be notified if my neighbor is building an ADU?