Four kinds of ADU
Weeks count the build only, after the city has approved your plans. The price depends on your lot, the utilities and the plans.
10 to 14 weeks to build. A separate unit made from space inside your house, up to 500 sq ft.
14 to 18 weeks to build. Your garage becomes a studio or a one-bedroom, usually 350 to 450 sq ft.
22 to 28 weeks to build. About 600 sq ft on its own foundation, with a kitchen, a bath and a laundry closet.
28 to 36 weeks to build. Up to 1,200 sq ft, or a one-bedroom over a new garage.
The price comes in writing after a site visit and the plans. Permit and utility fees, and any work the plans show on the main house, go on your written quote as allowances.
How pricing works
Your price depends on your lot, the utilities and the plans, and the written quote is what binds.
Permit fees and utility connections go on the quote as allowances and are billed at the actual cost.
Landscaping, fencing, retaining walls and work on the main house are separate lines if you want them.
Anything found behind a wall or under a slab is priced and signed before it is done.
We do not estimate rent, resale value or payback. Your lender or a real estate professional can.
A down payment as state rules allow, then stages as work is finished and inspected.
A worked example
This is an example, built to show how a written quote is laid out. Your lines will differ.
A 640 sq ft detached one-bedroomA made-up lot with a level yard, a rear alley and utilities about 40 feet from the new unit. | |
|---|---|
| Design, engineering and drawings | |
| Plan check and permit fees (allowance) | |
| Site work and foundation | |
| Framing, roof, windows and exterior | |
| Plumbing, electrical and mini-split | |
| Interior finishes, kitchen and bath | |
| Utility connections (allowance) | |
A worked example, not an offer. Your quote comes from your lot and your plans. We do not estimate rent, resale value or payback. |
Questions
After the lot check we visit, measure and talk through what you want. A written quote comes with the plans: scope, allowances, what is not included, and the timeline.
Size, how far the utilities are from the new unit, slope and access, soil, the condition of an old garage slab, finishes, and whether the city asks for upgrades to your electric panel or sewer line.
California law limits the down payment on a home improvement contract and gives you a short window to cancel. Your contract states both, with dates. After that you pay in stages as work is finished and inspected.
We do not lend money. Many owners use savings, a home equity loan or a renovation loan from their bank. A lender will want the written quote and the plans, and we provide both.
It can. Homes built before 1978 may have lead paint. If work disturbs more than 6 square feet of painted surface inside or 20 outside, or touches windows or demolition, federal rules require specific lead-dust work practices by a certified firm. Tell us the year; we say before you sign whether the rule applies and who holds the certification.
The lot check comes first. A written quote comes with the plans.