Every California ADU dataset published on BackyardADU, consolidated for journalists, policy researchers, and anyone who needs a citable reference. Updated October 2026 against HCD's October 2026 APR release and CSLB's April 28, 2026 contractor pull.
California ADU permits rose in steps as the state overrode local restrictions. The sharpest was 2017, the year SB 1069 and AB 2299 took effect: permits nearly quadrupled, from 1,336 in 2016 to 5,154. They grew a further 75% in 2018 and 67% in 2019. A second package (SB 13, AB 68, AB 881) took effect on January 1, 2020, followed by AB 2221 in 2023 and AB 976 and AB 1033 in 2024. Permit counts show the timing; they cannot by themselves show how much of each rise a given law caused.
2025's all-time high of 41,844 statewide permits represents +7.1% growth over 2024, down from +9% the year before. That single-digit growth rate is itself a story: California ADU permitting has matured out of the double-digit-growth phase that defined 2017–2022. Sustained 40,000+/year permitting now meaningfully contributes to the state's housing supply, but growth is now incremental.
Chart shows the statewide annual permit count (cities + county-unincorporated, matches the headline 41,844-in-2025 figure above). For geographic-concentration analysis below we use the cities-only filter (lifetime 198,026 permits vs the statewide 222,545; the difference is 57 county jurisdictions reporting for their unincorporated areas, left out so that cities are compared with cities).
California ADU permitting is heavily concentrated. The top 25 cities account for 62% of cities-only permits issued 2013–2025. Los Angeles alone has issued more ADU permits than the bottom 400 cities combined.
| # | City | Lifetime ADU permits 2013–2025 | Share of cities-only total |
|---|---|---|---|
| 1 | Los Angeles | 71,496 | 36.1% |
| 2 | San Diego | 9,249 | 4.7% |
| 3 | San Jose | 3,521 | 1.8% |
| 4 | Long Beach | 3,493 | 1.8% |
| 5 | Glendale | 3,469 | 1.8% |
| 6 | San Francisco | 2,875 | 1.5% |
| 7 | Garden Grove | 2,637 | 1.3% |
| 8 | Santa Maria | 2,556 | 1.3% |
| 9 | Fullerton | 2,299 | 1.2% |
| 10 | Oakland | 2,108 | 1.1% |
| 11 | Sacramento | 1,942 | 1.0% |
| 12 | Anaheim | 1,877 | 0.9% |
| 13 | Burbank | 1,642 | 0.8% |
| 14 | Oxnard | 1,309 | 0.7% |
| 15 | Campbell | 1,190 | 0.6% |
| 16 | Riverside | 1,186 | 0.6% |
| 17 | Santa Ana | 1,151 | 0.6% |
| 18 | Chula Vista | 1,150 | 0.6% |
| 19 | Torrance | 1,147 | 0.6% |
| 20 | Downey | 1,093 | 0.6% |
| 21 | Lakewood | 1,070 | 0.5% |
| 22 | Santa Barbara | 1,060 | 0.5% |
| 23 | Encinitas | 1,043 | 0.5% |
| 24 | Pasadena | 1,041 | 0.5% |
| 25 | Lancaster | 1,025 | 0.5% |
LA's permit dominance is not static. Its share of cities-only statewide permits jumped from under 10% pre-2017 to over 50% in 2017–2018 as it absorbed the bulk of the post-preemption demand first, then declined as other cities caught up. Table below uses cities-only totals throughout for consistency with the geographic-concentration analysis above.
| Year | LA ADU permits | Cities-only statewide | LA share |
|---|---|---|---|
| 2013 | 15 | 445 | 3.4% |
| 2014 | 71 | 445 | 16.0% |
| 2015 | 97 | 777 | 12.5% |
| 2016 | 80 | 903 | 8.9% |
| 2017 | 2,342 | 4,485 | 52.2% |
| 2018 | 4,079 | 8,084 | 50.5% |
| 2019 | 6,747 | 13,390 | 50.4% |
| 2020 | 6,012 | 14,488 | 41.5% |
| 2021 | 7,587 | 22,257 | 34.1% |
| 2022 | 10,304 | 28,705 | 35.9% |
| 2023 | 10,425 | 31,624 | 33.0% |
| 2024 | 11,410 | 34,985 | 32.6% |
| 2025 | 12,327 | 37,438 | 32.9% |
Across 64,173 completed ADU projects permitted 2018–2023, the median time from building permit to certificate of occupancy was 346 days (about 11.4 months). Half of projects took between 214 and 554 days, and 53% were finished within 12 months. Los Angeles's median is 407 days. The figures come from the same HCD file, by linking each project's permit and completion records across reporting years, and the Los Angeles figures were checked against the City's own permit system.
Measured build times for 166 cities, with method and limits →
In 2020, UC Berkeley's Center for Community Innovation graded 424 California jurisdictions' ADU ordinances against the then-current state law. Of those, 157 received letter grades; the remaining 267 jurisdictions were assessed but received a "—" placeholder (typically because the city had no ADU-specific ordinance, or the ordinance was too thin to assess).
| Grade | Jurisdictions | Share of graded |
|---|---|---|
| A | 9 | 5.7% |
| B | 41 | 26.1% |
| C | 92 | 58.6% |
| D | 13 | 8.3% |
| F | 2 | 1.3% |
| 267 jurisdictions were assessed but received a "—" placeholder (not graded). 424 jurisdictions appeared in Appendix C of the Scorecard; 157 received letter grades. | ||
The C-family was the median grade — most California cities had "doing the minimum" ordinances in 2020. State preemption has tightened materially since (AB-2221 stopped front setbacks from blocking an 800 sqft ADU and required written reasons with any denial; AB-976 made the owner-occupancy ban for ADUs permanent; AB-1033 let cities allow ADUs to be sold separately as condominiums; AB-1332 required pre-approved plan programs by 2025). The Scorecard is now best read as a historical snapshot of municipal intent rather than a direct reflection of current local law.
BackyardADU's cost figures are regression-based, derived from published 2026 builder pricing pages (Maxable, GreatBuildz, Abodu, Angi, CALI ADU, Andalusia Drafting, Maison Remodeling, Gather ADU, VerifiedADU). Per-sqft baselines below assume all-in design-build, Los Angeles baseline:
| ADU type | Low ($/sqft) | Typical ($/sqft) | High ($/sqft) | Default size |
|---|---|---|---|---|
| Detached | $300 | $380 | $500 | 750 sqft |
| Attached | $270 | $340 | $440 | 700 sqft |
| Garage conversion | $180 | $240 | $330 | 400 sqft |
| Junior ADU (JADU) | $160 | $220 | $300 | 400 sqft |
| Prefab | $250 | $320 | $400 | 600 sqft |
| Basement conversion | $200 | $275 | $380 | 600 sqft |
LA baseline 1.00×. Regional multipliers: Bay Area 1.30×, Central Coast 1.05×, San Diego 0.95×, Sacramento & Inland Empire 0.85×, Central Valley 0.75×.
Apply the regional multiplier to the LA baseline to get a per-city estimate. A 750-sqft detached ADU in Berkeley (Bay Area, 1.30×) at $380/sqft typical ranges roughly $370,000 to $487,000 all-in. The same unit in Fresno (Central Valley, 0.75×) ranges $213,000 to $281,000.
| Region | Cost multiplier (LA = 1.00) | Representative cities |
|---|---|---|
| Bay Area | 1.30× | SF, Oakland, San Jose, Berkeley, Palo Alto |
| Central Coast | 1.05× | Santa Barbara, SLO, Monterey, Santa Cruz |
| Los Angeles | 1.00× | LA, Long Beach, OC core |
| San Diego | 0.95× | SD city + county coastal |
| Sacramento | 0.85× | Sacramento, Roseville, Folsom, Davis |
| Inland Empire | 0.85× | Riverside, San Bernardino, Ontario, Palm Springs |
| Central Valley | 0.75× | Fresno, Bakersfield, Stockton, Modesto |
Regression-based figures should never substitute for real quotes. Get three builder quotes minimum before committing. Cost drivers not captured here include lot slope, sewer-line distance, utility undergrounding, soils-report results, asbestos remediation (older garages), and discretionary finishes.
BackyardADU surfaces CSLB-licensed contractors on every city page. The underlying CSLB Public Data Portal contains 244,112 total California contractor records (active and historical). Filtering to active, current class-B licenses leaves 102,004 contractors. Filtering further to firms whose CSLB business name explicitly contains an ADU keyword yields 144 ADU specialists — the directory we publish at /builders/.
The 144-specialist count is a high-precision, low-recall lower bound. Many firms specialise in ADUs without naming themselves accordingly (Smith Construction Inc may build 40% ADUs but never surface to a substring filter). Phase 2 of the directory will widen recall using Google Business Profile and Yelp Fusion API enrichment.
For each builder we display, the CSLB profile is linkable in one click ("Instant License Check") so users can verify licence status, bond, classification, and disciplinary history independently — we treat CSLB as the source of truth, not our denormalised cache.
Beyond the state-law minimums, 28 California cities have detailed local ordinance entries in BackyardADU's database, sourced directly from each city's planning-department webpage and dated. The currently-covered set: Anaheim, Berkeley, Burbank, Carlsbad, Chula Vista, Encinitas, Fremont, Garden Grove, Glendale, Long Beach, Los Angeles, Mountain View, Oakland, Palm Springs, Palo Alto, Pasadena, Rosemead, Sacramento, San Diego, San Francisco, San Jose, Santa Ana, Santa Barbara, Santa Cruz, Santa Monica, Santa Rosa, Solana Beach, and Westminster. Each entry records max ADU size, height limit, setbacks, units allowed per lot, parking requirements, and notable local provisions (e.g. Garden Grove's Municipal Code Chapter 9.54 + ADU Go pre-approved plans programme; Mountain View's preapproved ADU programme; Solana Beach's short-term-rental ban under Ordinance 525).
Big West Coast ADU Dataset published by BuildinganADU.com (Kol Peterson, January 2024 release), drawn from city building-department records aggregated by Karen Chapple's research team at the UC Berkeley Center for Community Innovation. Dataset license: CC BY 4.0 (free use with attribution). We use this layer only for 2013–2017 because HCD's APR framework didn't begin systematic ADU-line-item tracking until 2018.
California HCD Housing Element Annual Progress Report (APR) Table A2, downloaded from data.ca.gov on 2026-10-05 (HCD's October 2026 release, published 2026-10-02). Coverage: 467 jurisdictions reported 2025 ADU permits — more than the 461 that reported for 2024 — so 2025 is treated as a complete year. HCD revises the file continuously as cities amend filings (the 2024 total was 38,910 in the April 2026 release, 39,633 in September and 39,056 in October, and the first snapshot of 2025 carried only 360 jurisdictions and 25,289 permits). We refresh this layer whenever HCD re-publishes the file; every figure on this page is the October 2026 state of the record.
UC Berkeley Center for Community Innovation, "ADU Scorecard 2020" (Wegmann et al.), Appendix C. We extracted the grade column and ordinance-link column from the PDF appendix into a normalised CSV. Cities are matched to permit-volume data by exact name match.
CSLB Public Data Portal, master license file, retrieved April 28, 2026. The portal uses a two-stage ASP.NET postback — our scraper handles both stages. Filtering: status = "CLEAR", classification includes "B", expiration date > today, mailing address state = "CA". ADU specialist filter: substring match on business name against the keyword set {"adu", "accessory dwelling", "granny flat", "casita"}.
Per-sqft baselines derived from the median of published 2026 builder pricing across nine sources: Maxable, GreatBuildz, Abodu, Angi, CALI ADU, Andalusia Drafting, Maison Remodeling, Gather ADU, VerifiedADU. Regional multipliers calibrated against builder pricing pages for representative cities in each region. Regression-based — not real builder quotes for any specific project. Use as a pre-quote sanity check only.
| Data layer | Source | Refresh cadence | Last refresh |
|---|---|---|---|
| Permit history (legacy) | Big West Coast Dataset | None (fixed) | January 2024 release, used for 2013–2017 |
| Permit history (current) | HCD APR Table A2 | Each time HCD re-publishes the file | October 2026 (covers 2018–2025) |
| Build times | HCD APR Table A2, permit and completion dates linked by parcel | With each permit refresh | October 2026 |
| Ordinance grades | Berkeley Scorecard 2020 | One-off (no scheduled update) | 2020 |
| Local ordinances | City planning pages | Quarterly | April 2026 |
| CSLB builder file | CSLB Public Data Portal | Quarterly | April 28, 2026 |
| Cost regression | Builder pricing pages | Quarterly | April 2026 |
BackyardADU.net (2026). California ADU Statistics 2026: Permits, Costs, Ordinances and Builders. Available at https://backyardadu.net/statistics/. Underlying permit dataset CC BY 4.0; sources: Big West Coast ADU Dataset (Peterson 2024) for 2013–2017; California HCD Annual Progress Report (April 2026 release) for 2018–2025; UC Berkeley ADU Scorecard 2020 (Wegmann et al.) for ordinance grades; CSLB Public Data Portal (April 28, 2026) for contractor counts.
For journalists: figures on this page are dated and sourced. If you're publishing on a tight deadline and need a specific number we don't render here, email hello@decisionlab.com.au — typical response time is under 24 hours.
41,844 statewide (cities + county-unincorporated combined) — a new all-time high, up 7.1% from 2024. The cities-only filter (excluding the 57 county-unincorporated rows) gives 37,438.
222,545 between 2013 and 2025 across 456 cities plus county-unincorporated jurisdictions. The cities-only subtotal is 198,026.
Los Angeles, by a wide margin. LA accounts for 36% of all cities-only ADU permits issued statewide 2013–2025. Its share peaked at 52% in 2017–2018 and has settled near 33% in 2025 as more cities ramped up.
As of HCD's October 2026 release, 456 of California's 482 incorporated cities have permitted at least one ADU between 2013 and 2025. The long tail of cities with under 50 lifetime permits is still substantial.
UC Berkeley's Center for Community Innovation reviewed 424 California jurisdictions' ADU ordinances in 2020 against the then-current state minimums. 157 received letter grades; 9 As, 41 Bs, 92 Cs, 13 Ds, 2 Fs. State preemption has tightened repeatedly since 2020 (SB-897, AB-2221, AB-976, SB-1211), so the Scorecard is now best read as a historical snapshot of municipal intent rather than current law.
Depends on type and region. Using the Los Angeles baseline of $300–$500/sqft for a detached ADU (all-in design-build), a 750-sqft detached unit ranges roughly $225,000 (Central Valley, 0.75× multiplier) to $390,000+ (Bay Area, 1.30× multiplier). Garage conversions are the cheapest type at $180–$330/sqft. These are regression-based 2026 figures — always get three real builder quotes before committing.
102,004 active class-B (General Building) contractors are licensed in California by CSLB as of April 28, 2026. 144 of those explicitly identify as ADU specialists in their CSLB business name. The vast majority of the remaining ~102,000 are general B-license firms whose ADU experience varies; verify each candidate's licence status, bond, and reference projects before signing a contract.
The median is 346 days (about 11.4 months) from building permit to certificate of occupancy, measured over 64,173 completed ADU projects permitted 2018–2023 in HCD's records. Design and plan check happen before the permit and are not included. City-by-city figures, the method and its limits are at /adu-build-times/.
Permit volume: Big West Coast ADU Dataset (Peterson 2024, CC BY 4.0) for 2013–2017, combined with California HCD Housing Element Annual Progress Report Table A2 (October 2026 release) for 2018–2025. Ordinance grades: UC Berkeley Center for Community Innovation, ADU Scorecard 2020 Appendix C. Contractor counts: CSLB Public Data Portal (April 28, 2026). Cost regression: 2026 published builder pricing from Maxable, GreatBuildz, Abodu, Angi, CALI ADU, Andalusia Drafting, Maison Remodeling, Gather ADU, VerifiedADU. Full methodology at /methodology/.
Yes. The full permit dataset is downloadable as a CSV at /data/permits_ca.csv (CC BY 4.0 — free to use with attribution). The ordinance and CSLB layers are derived from public sources and are also free to cite. Suggested citation is on this page.
No. BackyardADU is an independent reference site. We aggregate and analyse public-domain data published by California HCD, CSLB, and the UC Berkeley Center for Community Innovation, with attribution. We are not affiliated with any state agency or research institution. Editorial questions: hello@decisionlab.com.au.