ADU

Santa Barbara runs two sets of accessory dwelling unit standards — one for a single larger unit, one for smaller units that let you build more than one. Which you pick decides your size, your height, and whether a coastal permit is in your future.

Most California cities are the only permit you have to win for a backyard ADU. South Lake Tahoe is not one of them — the regional planning agency has to sign off too, and it does not always allow what state law does.

Long Beach sorts backyard homes into two categories with different standards, and its published table sets some limits that state law no longer lets a city impose. Here is what applies before you draw anything.

Where your backyard cottage sits on the lot changes its setbacks completely in Sacramento — and the city's two rulebooks differ on something most owners never ask about until it is too late: whether you can rent it by the week.

These are not competing options — they stack, up to a point. The state's own guidance walks through the combinations, including the one arrangement where taking the lot split costs you every ADU you were counting on.

Five months into a stalled ADU application, most owners assume waiting is the only option. California law says otherwise: miss the deadline on a complete application, and the permit is approved by operation of law. Here's every clock the city is running against.

Your kids moved out and the back of the house is empty. California has a category for exactly that: a small independent unit carved out of the walls you already own, with no parking required and a kitchen the city can't make fancier than the law says.

You built the backyard unit, and now you'd rather sell it than rent it. California opened a door to that in 2024 — but only if your city walked through it first, and only after your mortgage lender signs off in writing.

The planner tells you the ADU needs a parking space, and the garage you were going to convert has to be replaced somewhere else on the lot. Both statements may be wrong. California law caps what a city can ask for — and lists six situations where it can ask for nothing at all.

Explore the regulations and opportunities for building ADUs and JADUs in Los Angeles, CA, to maximize property value and space.

You sketched a 1,000-square-foot backyard cottage and the city said their cap is smaller. Who wins? California's ADU law sets hard ceilings on what cities may restrict — and a guaranteed unit every city must approve.

Discover how Emily leveraged GoCodebook AI to explore ADU and JADU possibilities for her Cupertino property.

Los Angeles bars an accessory dwelling unit on a lot that sits in both a hillside area and a very high fire hazard severity zone — unless it qualifies for one of two exceptions. Here is what the city's own ordinance requires, what it caps a detached unit at, and the trade you make by taking the conditions route.

When an Accessory Dwelling Unit (ADU) shares a wall or ceiling with a garage, that separation must provide adequate fire protection between the habitable space and the area used for vehicle storage. The rules come from the 2025 California Residential Code (CRC) and the 2025 California Building Code (CBC), which apply to all R-3 Occupancy, Type VB residential construction.

San Francisco has a local backyard-home program and a state-mandated one, and the code decides which you get. One is faster with a size ceiling; the other has no unit cap on larger buildings but adds tenant-protection review.

The Planning Code sets no minimum size for a room inside an ADU — and the building code does. Section 207.2(e) stops the City imposing one; California Residential Code R312.1 still requires a habitable room to be at least 70 square feet.