Ways an ADU can be built

Detached

A separate building in the yard. The most private option, usually the strongest for rental income and resale. Up to 1,200 sq ft in much of the area.

Attached

Built onto the existing house, sharing a wall. Suits a narrow lot where a detached unit won't fit, and often costs less to connect to utilities.

Garage conversion

Turning a garage into a home. Usually the cheapest route, since the foundation, walls and roof already exist. You don't have to replace the parking.

Above the garage

A second storey over an existing or new garage. Adds a full unit without giving up yard, and keeps the parking underneath.

Second storey

Building up rather than out. The answer on a small lot with no room left at ground level.

Interior conversion

A basement, attic, or unused part of the house turned into a separate unit with its own entrance. Nothing new gets built.

Junior ADU (JADU)

Up to 500 sq ft carved out of the existing house, with its own entrance and kitchen. The cheapest unit you can add, and in most areas you can have a JADU and a full ADU on the same lot.

How it works

From the free consultation to handing you the keys, we handle it all

Design, engineering, permits, utility companies, inspections, construction and final sign-off. You make the decisions that matter and we deal with everything in between.

See the full process

What people build them for

Eight of the most common reasons. There are thirteen on the full list, including a couple almost nobody considers until someone mentions them.

Aging parentsA parent close by with their own front door, at a fraction of what a care facility costs each month.

Multigenerational livingThree generations on one property, sharing the land without sharing a kitchen.

Rental incomeA year-long lease, longer-term Airbnb stays, or furnished stays for traveling medical staff on 13-week contracts. Furnished rentals earn well above a standard lease. Most areas require ADU rentals to run 30 days or longer.

Business potentialSome people run a business from the property itself. A licensed residential care home for six or fewer elderly residents counts as a residential use under California law, so the zoning is treated like any other home on the street. Licensing is its own process, and worth advice before you commit.

Adult childrenSomewhere for a grown child to live while they save, without either of you losing your privacy.

Home office or studioGenuinely separate from the house. No commute, and no working at the kitchen table.

Investment propertyAn extra unit on a property you already own. More rent, more value, no second lot to buy.

Live-in helpA caregiver or nanny housed on site, with their own space.

See all thirteen reasons

What it costs against buying instead

Whatever your reason for adding an ADU, it is a significantly cheaper way to add living space than buying another home. On a 1,200 sq ft unit the gap works out at around $237,000, and the property tax difference keeps paying after that: buy a second property and it is reassessed in full, build and only the new construction is added. Compare it with your own numbers.

Beyond ADUs

Home additions

More room without moving. A bedroom, a suite, or a whole wing on the back of the house.

Garage conversions

Turning a structure you already own into a legal dwelling. Usually the least expensive route, because there is no new foundation or framing.

Ground-up homes

A house built from nothing on land you own or land we help you find.

Adding units to multifamily

California may allow more units on a property that already has multiple units, up to the number you already have. More rent, on land you already own. Restrictions apply and rules differ by area.

Can I build an ADU? See completed projects

ADUs, additions and renovations