Marin County building & ADU permits
Recent permit activity, updated continuously.
Marin County sits directly north of the Golden Gate and permits for its unincorporated communities — San Anselmo, Kentfield, Woodacre and the surrounding valleys. California's statewide ministerial ADU rules apply here in full, and the county's permit feed carries the contractor name and licence number alongside each record.
Igni is tracking 792 residential and building permits in Marin County, CA — including 5 classified accessory-dwelling-unit (ADU) filings. The most active ZIP is 94941. The most recent filing Igni tracked was Sep 30, 2026. All records come from data.marincounty.gov (Socrata), an official government open-data feed, and are refreshed continuously.
792
Permits tracked
5
ADU permits
23
Distinct ZIP codes
Sep 30, 2026
Newest permit
Recent permits
A sample of the freshest permits in this jurisdiction — ZIP and city only (no street addresses).
| ZIP | Permit type | ADU type | Valuation | Applied |
|---|---|---|---|---|
| 94930 | Residential | — | $20,000 | Jan 22, 2026 |
| 94941 | Residential | — | $70,000 | Mar 5, 2026 |
| 94903 | Residential | — | $116,456 | Mar 13, 2026 |
| 94964 | Residential | — | $80,000 | Jun 15, 2026 |
| 94904 | Residential | — | $240,000 | Mar 12, 2026 |
| 94973 | Residential | — | $3,100 | Sep 30, 2026 |
| 94904 | Residential | — | $20,000 | Sep 23, 2026 |
| 94973 | Residential | — | $2,309 | Sep 30, 2026 |
| 94903 | Residential | — | $37,000 | Sep 30, 2026 |
| 94941 | Residential | — | $24,808 | Sep 25, 2026 |
| 94941 | Residential | — | $7,000 | Sep 30, 2026 |
| 94904 | Residential | — | $15,000 | Sep 30, 2026 |
| 94941 | Commercial | — | $15,340 | Sep 30, 2026 |
| 94904 | Residential | — | $26,595 | Sep 30, 2026 |
| 94941 | Residential | — | $4,500 | Sep 30, 2026 |
| 94904 | Residential | — | $19,000 | Sep 29, 2026 |
| 94941 | Residential | — | $37,260 | Sep 30, 2026 |
| 94941 | Residential | — | $10,000 | Sep 30, 2026 |
| 94963 | Residential | — | $53,000 | Sep 30, 2026 |
| 94941 | Residential | — | $4,800 | Sep 30, 2026 |
Top ZIP codes by recent activity
ADU types in the recent set
Permit activity in Marin County
Igni counted 4,384 permits issued in Marin County over the last 12 months (Sep 2025 – Aug 2026) — roughly flat (+0.6%) on the 4,356 in the 12 months before. The forecast expects about 2,190 over the next 6 months.
Forecast: trailing mean, typical error ±13% in backtests one to six months ahead. How we forecast
| Permit type | Last 12 months | Year over year | Forecast, next 6 months |
|---|---|---|---|
| All permits | 4,384 | Flat (+0.6%) | ≈ 2,190 |
| Residential building | 4,129 | Flat (−0.6%) | ≈ 2,064 |
| Commercial building | 255 | Up 26.2% | — |
| Trade (electrical, plumbing, mechanical) | 0 | — | — |
| ADU | 18 | — | — |
Monthly figures
| Month | Permits | 10th–90th percentile |
|---|---|---|
| Sep 2023 | 370 | — |
| Oct 2023 | 397 | — |
| Nov 2023 | 325 | — |
| Dec 2023 | 283 | — |
| Jan 2024 | 306 | — |
| Feb 2024 | 306 | — |
| Mar 2024 | 326 | — |
| Apr 2024 | 370 | — |
| May 2024 | 348 | — |
| Jun 2024 | 305 | — |
| Jul 2024 | 372 | — |
| Aug 2024 | 353 | — |
| Sep 2024 | 336 | — |
| Oct 2024 | 392 | — |
| Nov 2024 | 346 | — |
| Dec 2024 | 321 | — |
| Jan 2025 | 428 | — |
| Feb 2025 | 338 | — |
| Mar 2025 | 341 | — |
| Apr 2025 | 417 | — |
| May 2025 | 362 | — |
| Jun 2025 | 330 | — |
| Jul 2025 | 377 | — |
| Aug 2025 | 368 | — |
| Sep 2025 | 448 | — |
| Oct 2025 | 479 | — |
| Nov 2025 | 335 | — |
| Dec 2025 | 343 | — |
| Jan 2026 | 379 | — |
| Feb 2026 | 323 | — |
| Mar 2026 | 272 | — |
| Apr 2026 | 319 | — |
| May 2026 | 315 | — |
| Jun 2026 | 407 | — |
| Jul 2026 | 372 | — |
| Aug 2026 | 392 | — |
| Sep 2026 (forecast) | ≈ 365 | 282–462 |
| Oct 2026 (forecast) | ≈ 365 | 281–437 |
| Nov 2026 (forecast) | ≈ 365 | 268–402 |
| Dec 2026 (forecast) | ≈ 365 | 262–397 |
| Jan 2027 (forecast) | ≈ 365 | 265–396 |
| Feb 2027 (forecast) | ≈ 365 | 265–392 |
Counts are permits issued per calendar month as Marin County publishes them to its open-data feed — not a complete census; a change in what the city publishes moves them too. The current month is left out, and the most recent months are provisional. A forecast is a statistical estimate with a range, not a prediction for any project. Informational only.
How long do permits take in Marin County?
Based on 11,349 Marin County permits applied for between Sep 2023 and Jun 2026, the typical (median) permit was issued same day after application, and the middle half of permits took same day. One in ten took longer than 84 days.
| Permit type | Median | Typical range | Permits |
|---|---|---|---|
| All permits | same day | same day | 11,349 |
| Residential building | same day | same day | 10,791 |
| Commercial building | same day | 0–5 days | 558 |
| ADU | same day | 0–127 days | 35 |
Typical, not guaranteed: individual permits vary with project scope, application completeness and plan-review workload. Days are calendar days from application to issuance; applications still pending are counted as not-yet-issued rather than dropped. Informational only, not legal advice. How we calculate approval times.
Housing law — California
California mandates ministerial (by-right) approval of accessory dwelling units statewide, with a 60-day decision deadline and one ADU plus one junior ADU allowed on most single-family lots; owner-occupancy is generally not required.
SB 9 allows by-right duplexes and urban lot splits on single-family lots, and newer transit-oriented upzoning (SB 79) phases in from 2026.
Data source
Sourced from data.marincounty.gov (Socrata). ODbL 1.0 — attribution required.
Attribution: © County of Marin, CA (ODbL 1.0)
Nearby cities — California
Learn more about ADUs & building permits
Background reading on accessory dwelling units, building permits, and how Igni turns Marin County permit records into leads.
Marin County permit data — FAQ
Where does Igni get Marin County permit data?
How fresh is Marin County permit data?
How long does it take to get a building permit in Marin County?
Is construction activity growing in Marin County?
Does Marin County allow accessory dwelling units (ADUs)?
Get permit leads — Marin County
Fresh, filterable residential and ADU permit leads from Marin County — delivered before your competitors even know.
Informational only, not legal advice. Headline counts reflect all permits Igni has tracked for this jurisdiction; the table shows recent activity. Housing law changes — verify current statutes before relying on this.