Yes, building an ADU will affect your property taxes, but usually in a manageable way. In California, your main home keeps its current assessed value, with only small yearly increases. Only the new ADU gets reassessed. The county uses a ‘blended assessment,’ so your total property tax rises only based on the ADU’s value, not the entire property. This allows you to add a backyard home and increase your property’s value without a major impact on your taxes.
