Cambridge building & ADU permits
Recent permit activity, updated continuously.
Cambridge sits across the Charles River from Boston and is home to Harvard and MIT. Under the 2024 Affordable Homes Act, ADUs are now allowed by right across Massachusetts; Cambridge publishes its new-construction permits under a public-domain (PDDL) license, which Igni ingests and classifies.
Igni is tracking 247 residential and building permits in Cambridge, MA — including 1 classified accessory-dwelling-unit (ADU) filing. The most active ZIP is 02138. The most recent filing Igni tracked was Oct 29, 2026. All records come from data.cambridgema.gov (Socrata), an official government open-data feed, and are refreshed continuously.
247
Permits tracked
1
ADU permits
5
Distinct ZIP codes
Oct 29, 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 |
|---|---|---|---|---|
| 02140 | Residential | — | $695,000 | Aug 25, 2026 |
| 02140 | Residential | — | $2,525,000 | May 14, 2026 |
| 02140 | Residential | — | $707,000 | Aug 25, 2026 |
| 02138 | Residential | — | $680,000 | Aug 21, 2026 |
| 02138 | Commercial | — | $9,975,000 | Jun 16, 2026 |
| 02140 | Residential | — | $800,000 | Apr 13, 2026 |
| 02140 | Residential | — | $800,000 | Apr 13, 2026 |
| 02141 | Residential | — | $0 | Oct 1, 2026 |
| 02140 | Residential | — | $800,000 | Apr 13, 2026 |
| 02140 | Residential | — | $720,000 | Apr 13, 2026 |
| 02140 | Residential | — | $800,000 | Apr 10, 2026 |
| 02138 | Residential | — | $1,898,000 | Mar 27, 2026 |
| 02140 | Residential | — | $2,373,166 | Mar 10, 2026 |
| 02138 | Residential | — | $260,000 | Jul 8, 2026 |
| 02139 | Residential | — | $1,290,000 | Dec 10, 2025 |
| 02140 | Residential | — | $2,703,997 | Aug 1, 2026 |
| 02141 | Residential | — | $2,268,600 | Jun 1, 2026 |
| 02139 | Residential | — | $850,000 | May 18, 2026 |
| 02139 | Residential | — | $850,000 | May 18, 2026 |
| 02138 | Residential | — | $1,000,000 | Dec 3, 2025 |
Top ZIP codes by recent activity
Permit activity in Cambridge
Igni counted 65 permits issued in Cambridge over the last 12 months (Oct 2025 – Sep 2026).
Forecast hidden — not accurate enough for this series. How we forecast
| Permit type | Last 12 months | Year over year |
|---|---|---|
| All permits | 65 | — |
| Residential building | 61 | — |
| Commercial building | 2 | — |
| Trade (electrical, plumbing, mechanical) | 0 | — |
| ADU | 1 | — |
Monthly figures
| Month | Permits | 10th–90th percentile |
|---|---|---|
| Oct 2023 | 2 | — |
| Nov 2023 | 3 | — |
| Dec 2023 | 10 | — |
| Jan 2024 | 4 | — |
| Feb 2024 | 0 | — |
| Mar 2024 | 5 | — |
| Apr 2024 | 4 | — |
| May 2024 | 2 | — |
| Jun 2024 | 3 | — |
| Jul 2024 | 5 | — |
| Aug 2024 | 1 | — |
| Sep 2024 | 3 | — |
| Oct 2024 | 8 | — |
| Nov 2024 | 2 | — |
| Dec 2024 | 2 | — |
| Jan 2025 | 6 | — |
| Feb 2025 | 1 | — |
| Mar 2025 | 3 | — |
| Apr 2025 | 0 | — |
| May 2025 | 3 | — |
| Jun 2025 | 1 | — |
| Jul 2025 | 3 | — |
| Aug 2025 | 2 | — |
| Sep 2025 | 2 | — |
| Oct 2025 | 2 | — |
| Nov 2025 | 0 | — |
| Dec 2025 | 5 | — |
| Jan 2026 | 4 | — |
| Feb 2026 | 5 | — |
| Mar 2026 | 5 | — |
| Apr 2026 | 2 | — |
| May 2026 | 5 | — |
| Jun 2026 | 14 | — |
| Jul 2026 | 10 | — |
| Aug 2026 | 6 | — |
| Sep 2026 | 7 | — |
Counts are permits issued per calendar month as Cambridge 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 Cambridge?
Based on 127 Cambridge permits applied for between Nov 2023 and Aug 2026, the typical (median) permit was issued 111 days after application, and the middle half of permits took 60–186 days. One in ten took longer than 248 days.
| Permit type | Median | Typical range | Permits |
|---|---|---|---|
| All permits | 111 days | 60–186 days | 127 |
| Residential building | 118 days | 60–189 days | 112 |
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 — Massachusetts
Massachusetts legalized accessory dwelling units by right statewide through the Affordable Homes Act (2024); as of February 2025, an ADU up to 900 sq ft is allowed by right in single-family zoning districts in nearly every community, without an owner-occupancy requirement.
The MBTA Communities Act (2021) requires the 177 MBTA-served cities and towns to zone for multifamily housing as of right near transit; the state's highest court upheld the law as constitutional and enforceable in 2025.
Data source
Sourced from data.cambridgema.gov (Socrata). PDDL — public domain.
Nearby cities — Massachusetts
Learn more about ADUs & building permits
Background reading on accessory dwelling units, building permits, and how Igni turns Cambridge permit records into leads.
Cambridge permit data — FAQ
Where does Igni get Cambridge permit data?
How fresh is Cambridge permit data?
How long does it take to get a building permit in Cambridge?
Does Cambridge allow accessory dwelling units (ADUs)?
Get permit leads — Cambridge
Fresh, filterable residential and ADU permit leads from Cambridge — 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.