Permit timeline data: garage-conversion and ADU waits in four cities
An open dataset of 64,427 residential garage-to-ADU and garage-to-habitable-room conversion permit applications in Los Angeles, San Diego, San Francisco, and Seattle, measured from each city's official permit records. Across the 19,848 issued permits in the mature cohorts, the median wait ranges from 69 days in the fastest city to 185 days in the slowest.
Download: aggregates CSV · cohorts CSV · JSON · record-level data + R package · Hugging Face · Version 2026.1 · Retrieved 2026-08-24 · CC BY 4.0
The wait, per city
Issued permits from each city's mature application-year cohorts. Days from application to issuance; within-60 is the share issued within 60 days of applying.
| City | Permits | p25 | Median | p75 | p90 | Within 60d | Cohorts |
|---|---|---|---|---|---|---|---|
| Los Angeles | 15,689 | 69 | 144 | 272 | 484 | 22% | 2021–2024 |
| San Diego | 3,197 | 94 | 185 | 359 | 540 | 15% | 2018–2021 |
| San Francisco | 541 | 14 | 69 | 219 | 485 | 47% | 2022–2025 |
| Seattle | 421 | 63 | 112 | 187 | 302 | 23% | 2022–2025 |
The review track decides the timeline
Never pool review tracks: a city's tracks can both get faster while the pooled median rises, purely from a mix shift. Cells under 30 records are suppressed and never shown as numbers.
| City | Review track | Permits | Median | Within 60d |
|---|---|---|---|---|
| Los Angeles | Plan Check at Counter | 1,898 | 106 | 32% |
| Los Angeles | Expanded Counter Plan Check | 9,180 | 112 | 29% |
| Los Angeles | Regular Plan Check | 4,610 | 243 | 3% |
| San Diego | Demolition Permit | 81 | 15 | 67% |
| San Diego | Electrical-Photovoltaic | 56 | 55 | 57% |
| San Diego | Construction Change - Building | 52 | 71 | 40% |
| San Diego | Encroachment Agreement | 37 | 117 | 27% |
| San Diego | Agreement | 168 | 132 | 26% |
| San Diego | Combination Building Permit | 2,302 | 179 | 13% |
| San Diego | Electrical Permit | 63 | 293 | 8% |
| San Diego | Mechanical Permit | 62 | 302 | 3% |
| San Diego | Plumbing Permit | 61 | 302 | 2% |
| San Diego | Building Permit | 80 | 325 | 4% |
| San Diego | Coastal Development Permit | 83 | 449 | 1% |
| San Francisco | otc alterations permit | 373 | 30 | 69% |
| San Francisco | additions alterations or repairs | 166 | 278 | 0% |
| Seattle | Addition/Alteration | 318 | 99 | 27% |
| Seattle | New | 98 | 170 | 9% |
Method
- Cohorts are formed on the application year, never the issue year. A large share of permits issued in any year were filed earlier, so issue-year grouping oversamples slow permits.
- Records are deduplicated on the permit number before anything is counted.
- Review tracks are never pooled into one median.
- Any aggregate cell under 30 records is suppressed.
- A city-year enters the aggregates once at least 75 percent of its applications have an outcome.
- Percentiles are lower-tail order statistics (quantile type 1, no interpolation).
- The clock excludes: Design, plan preparation, any planning review before the application is submitted, and everything after the permit is issued.
Read this before citing a number
- The measured wait is the homeowner calendar wait, not a statutory compliance measure. California Government Code 66317 runs its 60-day clock from a completed application and tolls on applicant delay; these records carry only the submission date.
- An application with no issued date had no issued permit when the records were retrieved. That may be a stalled review or an abandoned project; the records do not distinguish the two, and none are marked denied.
- Cross-city level comparison is not apples-to-apples; the trend within a city is sound.
Sources
All records come from official city portals, public record, retrieved 2026-08-24: Los Angeles · San Diego · San Francisco · Seattle. No city endorses this preparation. The build script that produced every number is committed in the open repository, and the interactive version lives in the permit timeline explorer.
Cite this data
Ichaki, A. (2026). Residential Garage-Conversion and ADU Permit Timelines for Los Angeles, San Diego, San Francisco, and Seattle. Version 2026.1. Renology. doi:10.5281/zenodo.22079794. https://www.therenology.com/data/permit-timelines
Archived with a DOI on Zenodo, so the citation resolves even if this page moves.