What is an ADU? An ADU (accessory dwelling unit) is a small second home on the same lot as a house, with its own kitchen and bathroom. Granny flats, in-law units, backyard cottages and garage conversions are all ADUs. More on what counts.
ADU building permits for the 54 California cities and counties with the most ADU activity, from the reports every jurisdiction files with the state. We include a place only if it reported at least 100 ADU permits in 2025 and at least 250 from 2021 to 2025, so every page has real numbers behind it.
| Rank (2025) | City or county | 2025 | 2024 | ADU share of new homes, 2025 |
|---|---|---|---|---|
| 1 | Los Angeles | 7,439 | 7,050 | 41.2% |
| 2 | San Diego | 2,165 | 2,281 | 28.4% |
| 3 | Unincorporated Los Angeles County | 1,298 | 1,013 | 41.5% |
| 4 | Long Beach | 644 | 747 | 52.9% |
| 5 | San Jose | 502 | 558 | 19.1% |
| 6 | Santa Maria | 479 | 435 | 51.5% |
| 7 | Garden Grove | 434 | 426 | 68.1% |
| 8 | Unincorporated San Diego County | 400 | 488 | 46.1% |
| 9 | Sacramento | 378 | 348 | 13.8% |
| 10 | Glendale | 371 | 229 | 96.1% |
| 11 | Anaheim | 266 | 277 | 58.8% |
| 12 | Santa Ana | 258 | 192 | 81.6% |
| 13 | Oxnard | 244 | 216 | 99.6% |
| 14 | Burbank | 241 | 270 | 84.9% |
| 15 | Fontana | 239 | 169 | 27.3% |
| 16 | San Bernardino | 230 | 138 | 57.2% |
| 17 | Unincorporated Riverside County | 227 | 9 | 11.6% |
| 17 | Unincorporated Santa Barbara County | 227 | 219 | 37.0% |
| 19 | Chula Vista | 223 | 245 | 31.1% |
| 20 | Pasadena | 222 | 208 | 31.8% |
| 21 | Westminster | 215 | 209 | 82.7% |
| 22 | Lancaster | 209 | 320 | 45.1% |
| 23 | Salinas | 208 | 216 | 94.1% |
| 23 | Riverside | 208 | 309 | 50.1% |
| 25 | Oakland | 192 | 213 | 27.0% |
| 26 | Fremont | 177 | 133 | 32.2% |
| 27 | San Francisco | 171 | 230 | 8.7% |
| 28 | Fullerton | 168 | 110 | 27.5% |
| 29 | Ontario | 154 | 158 | 8.0% |
| 31 | Inglewood | 147 | 18 | 98.7% |
| 32 | Downey | 146 | 200 | 72.3% |
| 33 | Santa Monica | 143 | 130 | 31.8% |
| 34 | Santa Barbara | 141 | 110 | 55.3% |
| 35 | Santa Clara | 140 | 55 | 26.4% |
| 36 | Unincorporated Kern County | 139 | 75 | 28.2% |
| 37 | Palo Alto | 136 | 128 | 78.2% |
| 37 | Rosemead | 136 | 94 | 76.4% |
| 40 | Coachella | 129 | 92 | 79.1% |
| 41 | Unincorporated Contra Costa County | 124 | 108 | 43.4% |
| 42 | Simi Valley | 122 | 93 | 57.3% |
| 43 | Norwalk | 119 | 81 | 96.7% |
| 43 | Saratoga | 119 | 74 | 55.6% |
| 43 | Baldwin Park | 119 | 102 | 86.9% |
| 46 | Escondido | 117 | 109 | 22.8% |
| 47 | Berkeley | 116 | 102 | 25.1% |
| 48 | Unincorporated Sonoma County | 110 | 134 | 36.1% |
| 49 | Modesto | 109 | 112 | 24.4% |
| 50 | Sunnyvale | 107 | 73 | 49.5% |
| 51 | El Monte | 105 | 86 | 48.4% |
| 52 | Alhambra | 102 | 115 | 74.5% |
| 52 | Unincorporated Stanislaus County | 102 | 73 | 55.1% |
| 54 | Fresno | 101 | 87 | 5.0% |
| 54 | Unincorporated Orange County | 101 | 62 | 25.7% |
| 56 | Vista | 100 | 126 | 52.9% |
Source: HCD APR Table A2. County entries cover unincorporated areas only. Method on the California ADU Data page.