California permitted 198,026 accessory dwelling units between 2013 and 2025 across 475 cities — and 2025 set a new all-time high at 37,438 city-issued permits (41,844 including county-unincorporated areas). This analysis uses California HCD's Annual Progress Report data as re-published on October 2, 2026; the complete 2025 reporting year first appeared in the September release. Headlines: 2025 is the new peak, but growth has slowed to +7.1% (from +67% in 2019 and +9% in 2024); Los Angeles grew faster than the rest of the state and its share edged up for the first time since 2022; and San Diego, the state's second market, slipped 5% after two years of rapid growth. Raw data is downloadable below.
California's modern ADU era began on January 1, 2017, when SB 1069 and AB 2299 took effect and stripped cities of much of their discretionary review authority. Statewide permits jumped from 1,336 in 2016 to 5,154 in 2017 — a near-quadrupling in twelve months.
Growth stayed steep for two more years: permits rose 75 percent in 2018, to 9,005, and 67 percent in 2019, to 15,086. That second rise came before the next round of legislation applied. SB 13, AB 68, and AB 881 were signed in October 2019 and took effect on January 1, 2020; the bundle barred owner-occupancy requirements until 2025, barred impact fees on ADUs under 750 square feet, set a 60-day deadline for ministerial approval, and required cities to allow a JADU alongside an ADU.
The COVID year was nearly flat (16,041 permits in 2020, +6%), then the recovery bent sharply upward. 2021 came in at 24,639 (+54%), 2022 at 31,805 (+29%). Through the Big West Coast Dataset's 2022 endpoint, the curve still looked steep.
HCD's data shows the curve has decisively bent. 2023 came in at 35,713 statewide (+12%), 2024 at 39,056 (+9%), and 2025 at 41,844 (+7.1%) — a new all-time high, and the slowest growth of any year since the reforms apart from pandemic-hit 2020. Growth has compressed from the +50–67% bursts that followed each preemption package to single digits. The market is maturing: 40,000-plus permits a year is a meaningful share of California's housing supply, but the explosive-growth phase of 2017–2022 is over.
These figures move, and readers should know how. The 2025 total went from a partial 25,289 (360 jurisdictions had filed by HCD's 1 April deadline) to 41,844 (467 jurisdictions) once late filers were in — HCD's first snapshot of any reporting year understates it by a third or more. Earlier years shift too as cities correct their filings: the 2024 total was 38,910 in HCD's April release, 39,633 in September and 39,056 in October, after Burbank, Temple City and others removed double-counted permits. Every figure here tracks HCD's October 2, 2026 release.
Through 2022, Los Angeles alone permitted roughly 35% of all city-issued California ADU permits. On the full 2013–2025 window its lifetime share is 36.1% (71,496 permits). Its share of each year's permits fell from above 50% in 2017–2019 to 32.6% in 2024, then edged up to 32.9% in 2025 — the first rise since 2022 — because LA grew 8% (11,410 to 12,327) while the rest of the state grew 6.5%.
San Diego remains the second mass-volume market at 9,249 lifetime permits (4.7% of the state), but after more than tripling between 2022 and 2024 it slipped in 2025: 2,165 permits, down 5% from 2,281. San Jose (3,521 lifetime, 502 in 2025), Long Beach (3,493 / 644) and Glendale (3,469 / 695) round out the top five; Glendale was the only one of the three to grow in 2025 (+24%).
Bay Area performance remains weak. San Francisco has permitted 2,875 ADUs over thirteen years and slipped further in 2025 (171, down from 231 — its lowest year since 2016). Oakland permitted 192. The pattern is consistent: cities dominated by single-family lots (LA, Long Beach, Garden Grove, Glendale, Fullerton, Santa Maria) permit ADUs at scale, while denser cities permit far fewer. The likely reason is housing stock, with fewer garages and backyards to convert or build in, though permit counts alone cannot prove it.
The fastest movers in 2025 were mid-sized Southern California cities: Lakewood more than doubled (197 to 498), Fullerton rose 40% (420 to 589), Oxnard 29% (386 to 497), Glendale 24%. The largest declines were Sacramento (533 to 378), San Diego, Lancaster (320 to 209), Long Beach (747 to 644) and Riverside (309 to 208). The latest-year column in the table below shows the 2025 count for each of the top 15 cities.
| # | City | Lifetime 2013–2025 | % of CA | 2025 alone | Share (vs LA) |
|---|---|---|---|---|---|
| 1 | Los Angeles | 71,496 | 36.1% | 12,327 | |
| 2 | San Diego | 9,249 | 4.7% | 2,165 | |
| 3 | San Jose | 3,521 | 1.8% | 502 | |
| 4 | Long Beach | 3,493 | 1.8% | 644 | |
| 5 | Glendale | 3,469 | 1.8% | 695 | |
| 6 | San Francisco | 2,875 | 1.5% | 171 | |
| 7 | Garden Grove | 2,637 | 1.3% | 434 | |
| 8 | Santa Maria | 2,556 | 1.3% | 479 | |
| 9 | Fullerton | 2,299 | 1.2% | 589 | |
| 10 | Oakland | 2,108 | 1.1% | 192 | |
| 11 | Sacramento | 1,942 | 1.0% | 378 | |
| 12 | Anaheim | 1,877 | 0.9% | 441 | |
| 13 | Burbank | 1,642 | 0.8% | 241 | |
| 14 | Oxnard | 1,309 | 0.7% | 497 | |
| 15 | Campbell | 1,190 | 0.6% | 340 |
UC Berkeley's Center for Community Innovation graded California ADU ordinances in 2020. They evaluated 424 jurisdictions across criteria including parking requirements, owner-occupancy rules, fee structures, design review, and clarity of submittal requirements. Cities received letter grades A through F.
We matched 139 graded cities to the permit data, and the grade does not predict volume. The median A-grade city has issued 136 ADU permits since 2013, against 339 for the median B-grade city, 204 for C and 163 for D. The A group's average looks enormous only because Los Angeles carries an A-minus; the other eight A-grade cities average 509 permits, below the B-grade average of 815. The Scorecard captures whether a city has gotten out of homeowners' way procedurally, not whether homeowners want to build.
A small city with a perfect ordinance and few aging-in-place homeowners willing to add backyard rentals will have a high grade and low permit volume. A larger city with a moderately permissive ordinance, severe housing pressure, and lots of convertible garages will have a B or C grade and high permit volume. The grade may capture one procedural barrier, but it is not sufficient to predict permit volume.
The Scorecard predicts whether a city has built the off-ramp. It does not predict whether anyone is on the highway.
Of the 475 California cities in our merged dataset, 72 — about one in seven — permitted fewer than ten ADUs across the entire 2013–2025 window. 19 cities permitted exactly zero. 166 cities (35 percent of the sample) permitted fewer than fifty over thirteen years.
The long tail is shrinking, slowly. The 2022-cutoff analysis had 137 cities under ten and 39 at zero; our 2024-cutoff version had 86 and 21. But the roughly 10,000-permit gain from 2022 to 2025 statewide came overwhelmingly from cities already in the top quartile growing further, not from the long tail starting to participate. 414 cities issued at least one ADU permit in 2025, and the top 25 still account for 62% of all city-issued permits.
Three hypotheses could explain the long tail; permit counts alone cannot test them. First, housing-stock incompatibility: many small Central Valley and Inland Empire cities have older housing without garages or basements suitable for conversion, and lot sizes that make detached new-build economically marginal at construction costs of $300+ per square foot. Second, who builds: ADUs are mostly built by owners who want rental income or housing for a family member, and those households are not spread evenly. Third, post-preemption knowledge gaps: many small-city homeowners simply do not know that state law has overridden their city's restrictive 2015-era ADU ordinance, and city planning departments — particularly those that opposed the preemption legislatively — have little incentive to publicise the new rules.
The third explanation is the only one a state housing policy can address. HCD's expanded technical-assistance program (launched 2023) and the AB 1332 pre-approved-plan framework (2025) both aim at it. 2025 was the first full year under AB 1332 and the long tail did not visibly activate; the 2026 cohort of permits is the next test of whether ADUs become a statewide tool or remain an LA-plus-coastal-metros phenomenon.
The market has clearly entered its second phase. The first phase (2017–2022) was the ramp: state preemption created legal space, homeowners and builders learned the rules, and the curve compounded at +20–67% per year. The second phase (2023+) is maturation: +12%, then +9%, then +7% — a decelerating trend and modest expansion of the producing-cities base.
The 2022-era prediction in this article's first version — "if 2021–2022 trend continues, 2023 will likely cross 30,000 and 2026 should approach 50,000" — was right on 2023 and now looks out of reach for 2026. Our May 2026 version, written on partial data, projected 2026 landing "closer to 47,000". With 2025 complete at 41,844 and growth at +7.1%, a repeat of that rate lands 2026 near 44,800; even a return to 2023's +12% only reaches about 47,000. Still record territory, but the curve is flattening.
Legislation could re-accelerate growth. AB 1033 lets cities that opt in allow ADUs to be sold separately as condominiums, a sub-market the historical data doesn't capture yet. AB 1332 requires every city to offer pre-approved ADU plans, which is meant to shorten plan review. SB 1211 expanded the allowances for ADUs on multifamily lots. And from January 1, 2027, AB 956 doubles the detached ADUs a single-family lot is entitled to, from one to two (see our summary of the 2027 laws).
What the next dataset will not show, but that homeowners should watch, is the ratio of detached new-builds to garage conversions. The economics differ radically — a $300/sqft detached new-build at 750 sqft is a $225,000 capital project; a $150/sqft garage conversion at 400 sqft is $60,000. As construction costs continue to outpace wage growth, the conversion share will likely rise, and the absolute permit count may grow more slowly than the project-count would otherwise predict. HCD's APR data captures both as "ADU" — the granular split has to come from individual city permit records.
The biggest single-city question for 2026–2027 is whether San Diego's 2025 dip (2,165, down 5%) is noise or a plateau. San Diego permitted 2,281 in 2024 — a fifth of LA's number despite being a fraction of LA's population — helped by its bonus-ADU programme. 2026 will tell whether that volume keeps scaling or whether 2024 marked its ceiling.
Permit data 2013–2017: Big West Coast ADU Dataset published by BuildinganADU.com (Kol Peterson), drawn from city building-department records aggregated and normalised by Karen Chapple's research team at the UC Berkeley Center for Community Innovation. The dataset's January 2024 release covers 2013–2022; we use it for 2013–2017 because HCD's APR framework didn't begin systematic ADU-line-item tracking until 2018.
Permit data 2018–2025: California HCD Housing Element Annual Progress Report (APR) Table A2, downloaded from data.ca.gov on 2026-10-05. Last refreshed by HCD on October 2, 2026. Filter: UNIT_CAT='ADU' AND BP_ISSUE_DT1 non-empty (building permit was actually issued, not just entitled). We sum the NO_BUILDING_PERMITS field per row, treating empty/0 as 1 since the permit-issue date implies a permit was issued. This matches HCD's own methodology in its public-facing APR Dashboard.
Why the source mix: our first published numbers for 2018–2022 used the Big West Coast Dataset's January 2024 snapshot. HCD's data has been continuously refreshed since then as cities re-file with corrected counts; the 2022 figure in our first version (24,851) is 31,805 in HCD's current release — a 28% upward revision largely from late and corrected filings. We migrated 2018+ to HCD-current values in May 2026 so the methodology is one consistent source for all post-preemption years, and we refresh it each quarter.
2025 completeness and revisions: 467 jurisdictions reported 2025 ADU permits in HCD's October 2026 release — more than the 461 that reported for 2024 — so we treat 2025 as a complete year and no longer flag it as partial. HCD data is revised continuously as cities amend filings (the 2024 total moved up 1.9% and then down 1.5% across the April, September and October releases), so treat every figure as the October 2026 state of the record rather than a final count.
Ordinance grades: California ADU Scorecard 2020, UC Berkeley Center for Community Innovation, Appendix C. Grades reflect the legal text of each city's adopted ADU ordinance as of the 2020 evaluation. Subsequent state legislation (including SB 897, AB 2221 and AB 976) raised the floor for every city; cities that have not updated their ordinances to reflect post-2020 state law may have effectively higher or lower grades than the Scorecard indicates depending on how much the local text now contradicts state law.
City vs county: county jurisdictions report permits for their unincorporated areas. We leave them out of the city-level analysis above (top 15, long-tail counts, grade-vs-volume) so that cities are compared with cities, and include them in the statewide totals. Including the 57 county jurisdictions brings the statewide 2013–2025 total from 198,026 (cities only) to 222,545.
Corrections (October 5, 2026): the September 2026 version of this article contained four statements the data does not support, now fixed. It said Los Angeles's share had risen for the first time since 2018 (it last rose in 2022); that San Francisco's 2025 total was its lowest since 2018 (it is the lowest since 2016); that San Diego's 2025 fall was its first (it also fell in 2020 and 2022); and that 2025's increase was the smallest since the 2017 reforms (2020's was smaller). It also listed Burbank and Temple City among 2025's steepest declines; those were artefacts of double-counted 2024 permits that both cities have since corrected with HCD. Three older errors are fixed as well: the article said SB 13, AB 68 and AB 881 took effect in 2019 (they took effect on January 1, 2020); it called the 2019 increase the largest of the period (2018's was larger); and it said A-grade cities out-permit lower-graded ones once Los Angeles is set aside (on the current data they do not).
Reproducibility: all numbers in this article are computed live at build time from data/permits_ca.csv (5,269 rows of city × year × permits). The full file is downloadable. The refresh script (scripts/refresh_permits_hcd.py) rebuilds the file from HCD's Table A2 in one step — the analysis is reproducible end-to-end.
The full extracted dataset is downloadable as CSV — 5,269 rows of city × year × permit count, covering 475 California cities and 57 county jurisdictions, 2013–2025. Cite as: "BackyardADU.net California ADU permits dataset, October 2026 release. Sources: Big West Coast ADU Dataset (2013–2017) + California HCD Annual Progress Report (2018–2025)."
If you're a journalist working on a California housing story and want underlying methodology notes, custom slices, or a specific city deep-dive, email hello@decisionlab.com.au. We're happy to help.
222,545 across all jurisdictions 2013–2025 (198,026 in incorporated cities, the rest in county unincorporated areas). 2025 alone added 41,844. Figures are from HCD's October 2026 release, which carries the complete 2025 reporting year.
Los Angeles, by an enormous margin — 71,496 ADUs from 2013 to 2025, 36% of all city-issued California ADU permits in that window. The next-largest city, San Diego, permitted 9,249. LA permitted 12,327 in 2025 alone, up 8% on 2024.
Permit volume rose sharply after they took effect. Statewide ADU permits went from 1,336 in 2016 to 5,154 in 2017 — a near-quadrupling — the year SB 1069 and AB 2299 took effect, and 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. By 2025 California was permitting 41,844 ADUs annually, 31 times the 2016 figure.
2025 — 41,844 statewide ADU permits issued (cities + county-unincorporated combined). That is a new all-time high, up 7.1% from 2024's 39,056 and 32% from 2022. Every year since 2017 has set a new record.
Yes, materially. Annual growth was +67% in 2019, +54% in 2021, +29% in 2022, then +12% in 2023, +9% in 2024 and +7% in 2025. The market is in its mature phase. Jumps like those of 2017–2019 are unlikely to repeat without new legislation; AB 956's two-unit rule, which starts on January 1, 2027, is the next change that could move the numbers.
Three likely reasons. First, housing-stock incompatibility — many older or smaller cities lack convertible garages or have lot sizes too small for detached new-builds at $300+/sqft construction costs. Second, who builds — ADUs are mostly built by owners wanting rental income or housing for family, and those households are not spread evenly. Third, post-preemption knowledge gaps — many homeowners and city planning departments have not yet adjusted to the fact that state law overrides previously-restrictive local ordinances. 72 of 475 California cities permitted fewer than 10 ADUs over the entire 2013–2025 window.
From /data/ — we publish the merged dataset as a 5,269-row CSV, free, CC BY 4.0 for any reuse with attribution. Original underlying sources: Big West Coast ADU Dataset (2013–2017) and CA HCD APR Table A2 (2018–2025, October 2026 release).