800 sq ft ADU floor plans
800 sq ft is the size every California city has to allow for an ADU, with 4 ft side and rear setbacks. It fits a 2 bedroom with one bath, or a 1 bedroom with a large living room. Both layouts below are measured and editable.
800 sq ft 2 bedroom
| Kitchen | 15' x 7'-6" |
|---|---|
| Bath | 6' x 7'-6" |
| Laundry closet | 5' x 7'-6" |
| Living | 12'-6" x 18'-11" |
| Hall | 17'-10" x 3'-6" |
| Bedroom 1 | 8'-11" x 15'-5" |
| Bedroom 2 | 8'-11" x 15'-5" |
$293K to $392K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
More floor plans to start from
800 sq ft 1 bedroom
$293K to $392K estimated build cost in Sacramento. Add your ZIP in the editor for your area.
Why 800 sq ft is the safe size
Cities may set their own size limits, but they can't use them to block an 800 sq ft ADU with 4 ft side and rear setbacks (Gov. Code 66321(b)(3)). That makes 800 sq ft the size most likely to pass on a typical lot.
As a 2 bedroom it gives two bedrooms of about 9 by 15 ft. As a 1 bedroom it gives a living room of about 25 by 16 ft.
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
Can I build an 800 sq ft ADU anywhere in California?
On most single-family lots, yes, within 4 ft side and rear setbacks. Local rules on height, fire zones, easements and historic districts can still apply; check your lot.
1 or 2 bedrooms at 800 sq ft?
Two bedrooms usually rent for more. One bedroom gives a much bigger living room and costs a little less to build.
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.