ADU floor plans, studio to 3 bedroom
These ADU floor plans run from a 400 sq ft studio to a 1,100 sq ft 3 bedroom, sized to California's ADU limits. Open any of them in the editor to change the size and rooms, see it in 3D, and download the layout as a CAD file.
600 sq ft 1 bedroom
| Kitchen | 15'-2" x 8' |
|---|---|
| Bath | 6' x 8' |
| Laundry closet | 5' x 8' |
| Living | 16'-8" x 14'-11" |
| Bedroom | 9'-6" x 14'-11" |
$240K to $321K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
More floor plans to start from
400 sq ft studio
$186K to $250K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
500 sq ft 1 bedroom
$213K to $286K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
800 sq ft 2 bedroom
$293K to $392K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
1,100 sq ft 3 bedroom
$372K to $499K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
2-car garage conversion, 1 bedroom
$95K to $155K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
500 sq ft junior ADU, 1 bedroom
$68K to $120K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
Picking a size
A studio works from about 300 sq ft. A comfortable 1 bedroom starts near 500, a 2 bedroom near 550 to 800, and 3 bedrooms need about 700 sq ft or more. Every extra 100 sq ft adds cost, so many owners land between 500 and 800.
In California, a detached ADU can be up to 1,200 sq ft, and every city has to allow at least 800 sq ft. A junior ADU, made inside the house, tops out at 500.
California ADU size rules
- Detached ADU, largest
- Total floor area of a detached ADU can't exceed 1,200 sq ftGov. Code 66314(d)(5)
- What every city must allow
- A city can't use size, lot coverage or similar limits to block an ADU of at least 800 sq ft with 4 ft side and rear setbacksGov. Code 66321(b)(3)
- Attached ADU
- With an existing home, an attached ADU can't exceed 50 percent of the home's floor areaGov. Code 66314(d)(4)
- Junior ADU
- No more than 500 sq ft, inside the existing homeGov. Code 66333
Outside California, ADU size limits are set by each city or county. Your city's planning desk has the final word.
Will it fit your lot?
For homes in the California areas we cover, the free lot check reads your parcel, setbacks and local rules and shows the biggest unit that fits.
Check your lotQuestions
What is the most popular ADU size?
Between 500 and 800 sq ft: big enough for a real 1 or 2 bedroom, small enough to keep cost and setbacks easy. In California, 800 sq ft is the size every city must allow.
Do these ADU floor plans come as CAD files?
Yes. Each layout downloads as a DXF in inches, layered for walls, doors, windows and labels, ready to send to the designer who prepares your permit set.
Are these pre-approved ADU plans?
No. Some cities offer pre-approved plan sets; these are concept layouts to plan size and rooms. Ask your city whether it has pre-approved plans before you hire a designer.
Last checked 2026-11-02. Costs are estimates priced at ZIP 95818, not bids. Floor plans are concept layouts; a licensed designer or architect prepares the plans your city approves.