Attached ADUs in San Francisco

A new unit built onto your home, sharing a wall with it but with its own door, kitchen and bath.

Single-story modern house with white walls and dark trim

When does attached make sense?

When the back yard is small, when you want to use existing utility connections, or when an addition fits the lot better than a separate cottage.

Studio unit with a kitchenette, small dining table and bed beyond a partition

What is different from a detached ADU?

It ties into the house: the roof, the foundation and often the fire separation between the units. That shared wall is designed carefully for sound and fire.

Can part of my house become the ADU?

Yes. Converting existing space, such as a basement or a wing of the house, is often simpler than building new, and state law treats conversions more flexibly on size and setbacks.

Additions and under-house units

On sloped lots, an attached ADU often sits under the main floor on the downhill side. The State Program does not require rear yard or exposure standards to be met; the Local Program offers waivers only for existing buildings.

Is your lot ready for an ADU?

Send your address and a sentence about what you want. We look up the zoning, setbacks and utility routes and reply with the ADU types that fit.

We build in San Francisco, CA.