Montgomery County building & ADU permits
Recent permit activity, updated continuously.
Montgomery County is Maryland's largest jurisdiction and a close-in Washington DC suburb, spanning Bethesda, Silver Spring, Rockville, Takoma Park and Gaithersburg. The county has allowed accessory dwelling units county-wide since its 2019 zoning amendment, and its Department of Permitting Services publishes residential building permits as public-domain open data, which Igni ingests with per-row city, ZIP and coordinates.
Igni is tracking 1,040 residential and building permits in Montgomery County, MD — including 12 classified accessory-dwelling-unit (ADU) filings. The most active ZIP is 20817. The most recent filing Igni tracked was Sep 30, 2026. All records come from data.montgomerycountymd.gov (Socrata), an official government open-data feed, and are refreshed continuously.
1040
Permits tracked
12
ADU permits
34
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 |
|---|---|---|---|---|
| 20882 | Residential | — | $62,251 | Sep 30, 2026 |
| 20842 | Residential | — | $10,000 | Aug 5, 2026 |
| 20910 | Residential | — | $80,000 | Aug 17, 2026 |
| 20817 | Residential | — | $3,500 | Sep 21, 2026 |
| 20905 | Residential | — | $2,500 | Sep 1, 2026 |
| 20815 | Residential | — | $60,000 | Aug 19, 2026 |
| 20853 | Residential | — | $48,900 | Sep 9, 2026 |
| 20816 | Residential | — | $15,000 | Sep 14, 2026 |
| 20832 | Residential | — | $16,000 | Sep 30, 2026 |
| 20852 | Residential | — | $29,000 | Sep 24, 2026 |
| 20906 | Residential | — | $24,640 | Sep 30, 2026 |
| 20882 | Residential | — | $210,000 | Sep 14, 2026 |
| 20876 | Residential | — | $23,522 | Sep 30, 2026 |
| 20854 | Residential | — | $28,000 | Sep 23, 2026 |
| 20904 | Residential | — | $1,500 | Sep 22, 2026 |
| 20855 | Residential | — | $40,795 | Sep 10, 2026 |
| 20854 | Residential | — | $45,936 | Sep 25, 2026 |
| 20882 | Residential | — | $13,000 | Jun 1, 2026 |
| 20707 | Residential | — | $28,966 | Sep 14, 2026 |
| 20814 | Residential | — | $41,930 | Aug 14, 2026 |
Top ZIP codes by recent activity
Permit activity in Montgomery County
Igni counted 6,377 permits issued in Montgomery County over the last 12 months (Sep 2025 – Aug 2026) — up 2.4% on the 6,227 in the 12 months before. The forecast expects about 3,186 over the next 6 months.
Forecast: trailing mean, typical error ±16% in backtests one to six months ahead. How we forecast
| Permit type | Last 12 months | Year over year | Forecast, next 6 months |
|---|---|---|---|
| All permits | 6,377 | Up 2.4% | ≈ 3,186 |
| Residential building | 6,377 | Up 2.4% | ≈ 3,186 |
| Commercial building | 0 | — | — |
| Trade (electrical, plumbing, mechanical) | 0 | — | — |
| ADU | 125 | — | — |
Monthly figures
| Month | Permits | 10th–90th percentile |
|---|---|---|
| Sep 2023 | 569 | — |
| Oct 2023 | 580 | — |
| Nov 2023 | 515 | — |
| Dec 2023 | 471 | — |
| Jan 2024 | 468 | — |
| Feb 2024 | 458 | — |
| Mar 2024 | 528 | — |
| Apr 2024 | 564 | — |
| May 2024 | 564 | — |
| Jun 2024 | 483 | — |
| Jul 2024 | 566 | — |
| Aug 2024 | 653 | — |
| Sep 2024 | 579 | — |
| Oct 2024 | 582 | — |
| Nov 2024 | 494 | — |
| Dec 2024 | 434 | — |
| Jan 2025 | 424 | — |
| Feb 2025 | 484 | — |
| Mar 2025 | 509 | — |
| Apr 2025 | 546 | — |
| May 2025 | 484 | — |
| Jun 2025 | 447 | — |
| Jul 2025 | 626 | — |
| Aug 2025 | 618 | — |
| Sep 2025 | 564 | — |
| Oct 2025 | 659 | — |
| Nov 2025 | 594 | — |
| Dec 2025 | 587 | — |
| Jan 2026 | 363 | — |
| Feb 2026 | 335 | — |
| Mar 2026 | 438 | — |
| Apr 2026 | 525 | — |
| May 2026 | 570 | — |
| Jun 2026 | 594 | — |
| Jul 2026 | 616 | — |
| Aug 2026 | 532 | — |
| Sep 2026 (forecast) | ≈ 531 | 339–653 |
| Oct 2026 (forecast) | ≈ 531 | 342–626 |
| Nov 2026 (forecast) | ≈ 531 | 342–627 |
| Dec 2026 (forecast) | ≈ 531 | 343–622 |
| Jan 2027 (forecast) | ≈ 531 | 343–613 |
| Feb 2027 (forecast) | ≈ 531 | 344–612 |
Counts are permits issued per calendar month as Montgomery 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 Montgomery County?
Based on 17,067 Montgomery County permits applied for between Sep 2023 and Jun 2026, the typical (median) permit was issued 21 days after application, and the middle half of permits took 7–45 days. One in ten took longer than 92 days.
| Permit type | Median | Typical range | Permits |
|---|---|---|---|
| All permits | 21 days | 7–45 days | 17,067 |
| Residential building | 21 days | 7–45 days | 17,067 |
| ADU | 38 days | 20–82 days | 264 |
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 — Maryland
Accessory dwelling units in Maryland are regulated locally; there is no statewide ADU mandate, so rules vary by city and county.
Maryland has no statewide upzoning law; residential density is set by local zoning, with several counties pursuing their own reforms.
Data source
Sourced from data.montgomerycountymd.gov (Socrata). Public domain.
Nearby cities — Maryland
Learn more about ADUs & building permits
Background reading on accessory dwelling units, building permits, and how Igni turns Montgomery County permit records into leads.
Montgomery County permit data — FAQ
Where does Igni get Montgomery County permit data?
How fresh is Montgomery County permit data?
How long does it take to get a building permit in Montgomery County?
Is construction activity growing in Montgomery County?
Does Montgomery County allow accessory dwelling units (ADUs)?
Get permit leads — Montgomery County
Fresh, filterable residential and ADU permit leads from Montgomery 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.