For the city of Santa Clara, when you determine how big an ADU you can build, you need to consider the constraint of Maximum Building Coverage.
Each city has regulation that limit how much of your lot you can use for building or structure of any kind. For the city of Santa Clara, see Santa Clara city code on Maximum Building Coverage. Please note that this is just one of many constraints on how big an ADU you can build. Look around and see other posts for additional information. Have a question? Contact us.