New state laws have made it easier than ever to build a second unit in California. Start by visiting your city to discuss your ideas. Use our calculator to learn more about costs, rents, and the value of second units.
Learn more on the second unit calculator page.

Imagine all the ways your second unit will be used over the years. Who will live there? How much space do they need? How fancy will it be? Will it have special features like wheelchair access or a garden? Consider using a designer, architect or builder to help you follow all the rules and refine your budget.
Learn more on the designing page.

A new state law makes it easier, faster and cheaper to get permits for second units, but each city still has its own process. Visit your city’s Planning and Building Department to learn the rules, pick up forms and ask about fees. Experienced professionals definitely make the process easier.
Learn more on the permitting page.

Get detailed bids from several contractors, call their references and check their licenses with the state. Get a written contract that lists all costs and details up front to avoid expensive changes later. Communicate frequently and verify progress before making payments. Learn more on the permitting page.

Construction is complete, and now it’s time for someone to move in. This may be you, a friend, family member or renter. If it is a tenant, there are plenty of resources to help you become a landlord, including organizations that help you manage your unit. Consider pricing the unit so a school teacher, nurse or firefighter can move in.
Learn more on the permitting page.