BackyardADU
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Can you build an ADU in your backyard?

Type your address and lot size. In about thirty seconds you get the ADU rules that apply, a 2026 cost range, build-time figures for your city where permit records allow, and the option to ask for a builder introduction. Free, and no email is needed to see your result.

Check your lot

Figures come from state permit records and published 2026 builder pricing. How we measure.

What a result looks like
  • Pasadena: detached ADU $135k–$360k · median build 349 days
  • San Diego: detached ADU $128k–$342k · median build 358 days
  • Sacramento: detached ADU $114k–$306k · median build 268 days
Find your city Quick cost estimate California ADU statistics
A detached backyard ADU with a flat roof, a bright green front door and a small patio
Example detached ADU in Oregon. “An Oregon Detached Secondary Suite” by Sightline Institute, via Wikimedia Commons, CC BY 2.0, cropped and resized.
CA city guides published
258
Statewide ADUs permitted 2013–25
222,545
Licensed CA builders indexed
144
Permit data through
2025

Directory

Top ADU markets in California

These are the cities with the most permitted ADUs since California's 2017 zoning reforms.

Los Angeles

A- 71,496 permits

San Diego

B 9,249 permits

San Jose

B 3,521 permits

Long Beach

C+ 3,493 permits

Glendale

C 3,469 permits

San Francisco

A- 2,875 permits

Garden Grove

C 2,637 permits

Fullerton

C+ 2,299 permits

See all California cities →

For journalists & researchers

California ADU statistics 2026

The headline data, sourced and dated. 222,545 permits issued 2013–2025, Berkeley ordinance grades for 424 jurisdictions, 2026 cost regression across seven regions, and CSLB-verified contractor counts — all on one citable page. Suggested citation provided.

Read the statistics hub →   Download the raw CSV

New: measured ADU build times for California cities, and the ADU laws taking effect on January 1, 2027.

What's inside

What you'll find on every city page

Real 2026 cost ranges

Per-square-foot pricing by ADU type, regionalised for the Bay Area, LA, San Diego, Sacramento and Central Valley.

Local zoning rules

State-law minimums plus links to your city's actual ordinance text. What's allowed, what isn't, what changed.

Permit history through 2025

How many ADUs your city has actually permitted, year by year. Sourced directly from California HCD Annual Progress Reports (October 2026 release). Raw data →

Licensed builders

CSLB-verified ADU specialists in your area. License number, classification, and date issued visible.

Measured build times

How long ADUs have actually taken in your city, from building permit to certificate of occupancy, from state records. All cities →

2027 law changes

Two detached ADUs per lot, impact fees only above 750 sqft, a cap on plan-check rounds. What changes on January 1 →

About

Why we built this

Most "ADU cost in [city]" results are written by builders pitching themselves. We're not a builder. No builder can pay to appear in our directory or to rank in it; the only money we may take from a builder is a disclosed referral fee when you ask us for an introduction. BackyardADU compiles public data — CSLB, the California ADU Scorecard, the Big West Coast ADU Dataset, and city ordinance text — so homeowners can decide with eyes open.

More about how this site works →

Check my lot: rules, cost, build time