Find the house hiding in your backyard.
A backyard home, or ADU, can house family or bring in rent. Draw your lot and see what fits after setbacks, before you pay anyone for plans.
Try it on a typical lot
A 50 × 120 ft lot with a 36 × 40 ft house. Drag the size and watch the backyard unit.
Why now
States have been making backyard homes easier to build. California leads; others leave it to each city.
4 ft
Side and rear setbacks
California cities can't require more than 4 feet from side and rear lot lines for a new ADU.
850
Square feet, at least
California cities can't cap ADU size below 850 sq ft, or 1,000 sq ft with more than one bedroom.
60
Days to decide
In California, an ADU application must be approved or denied within 60 days.
Source: California HCD, Housing Law Fact Sheet: Accessory Dwelling Unit (April 2026). Other states differ; see ADU rules.
From sketch to keys
- Plan the lot here, free.
- A feasibility review: your city's rules, utilities and access, in writing.
- Introductions to designers and builders who do ADUs.
- Permits, build, and a home that pays you back.