How demolition review works
The rules are on the Commission's Demolition Delay page.
| Step | What happens |
|---|---|
| Which buildings | "all buildings over 50 years old, city-wide" |
| What counts | "pulling down, destroying, removing or razing a building" |
| 1. Ask first | Email the Executive Director for an initial determination of significance |
| 2a. Not significant | Apply for the demolition permit in the City's OpenGov portal |
| 2b. Significant | A public hearing is scheduled and a placard posted on the site |
| Garages and sheds | Utilitarian structures such as some residential garages generally get staff sign-off, no hearing |
| 3. Hearing | The Commission votes whether the building is significant and whether preservation is in the public interest; you present plans for what replaces it |
| Delay | Up to twelve months (six months before the November 2019 change) |
| After the delay | Demolition may go ahead once the site plans comply and permits are issued, unless the Commission starts a landmark study |
| Approval life | Six months; the Chair may extend by six |
A building is also significant if it is in a historic district. The Commission's office is at 831 Massachusetts Ave., 2nd floor (617-349-4683).
Historic and conservation districts: a certificate for exterior work
Demolition delay applies everywhere. In a district, smaller exterior work is reviewed too. The Commission's application forms page lists:
| District | Type | Application |
|---|---|---|
| Old Cambridge, Fort Washington | Historic district | CHC application |
| Harvard Square | Conservation district | CHC application, plus a posted notice placard |
| Avon Hill, Half Crown-Marsh, Mid Cambridge | Neighborhood conservation district | Each has its own application |
| Landmarks and properties with preservation restrictions | Individual | CHC application |
In the Mid Cambridge district (established 1985), the Commission says "One of these certificates is always necessary to obtain a building permit": a Certificate of Non-Applicability for interior work, work not visible from a public way or in-kind work (generally issued by staff on the spot), a Certificate of Appropriateness for reviewable changes, or occasionally a Certificate of Hardship. Reviews there are binding or advisory depending on the scope (Mid Cambridge NCD). Check each district's own page for its review criteria.
What it means for hiring a contractor
- Before a demolition bid, get the significance answer. A tear-down quote built on starting in spring is worthless if the house is found significant and delayed twelve months. One email to the Executive Director answers it.
- Partial demolition. "Removing" part of a building can count. Ask the Commission before a contractor prices taking down a rear ell or porch on an old house.
- In a district, the certificate comes first. Your contractor cannot get the building permit without it, so a start date in the contract should depend on the certificate date.
- Watch the six-month clock. If the job slips, an approval can lapse before the permit is pulled.
What Cambridge permits show
| Measure | Demolition | New homes | Remodels |
|---|---|---|---|
| Permits on homes, October 2023 to September 2026 | 133 | 111 | 3,512 |
| Firms | 104 | 67 | 1,395 |
| Usual filed value | $20,000 | $850,000 | $24,805 |
| Usual days to close | 697 | 524 | 304 |
Demolition is rare in Cambridge and slow: 133 permits in three years against 3,512 remodels, and the usual demolition permit stayed open 697 days. The usual new-home permit took 524 days to close, so a tear-down and rebuild runs for years in the records, before any delay. The work is also spread thin: the five busiest firms hold 14.3% of demolition permits. Values by firm are on Cambridge demolition cost and Cambridge new home cost; permit timing for every trade is on how long a Cambridge permit takes.
Compare Cambridge demolition contractors by permits →
Check it in five minutes
- Find the construction date; Commission staff can confirm it from their archives.
- Check whether the address is in one of the districts on the application forms page.
- Email the Executive Director through the Commission's contact form for an initial significance determination.
- Look up past permits for the address in our Cambridge building permit search guide.
What this does not tell you
Our file shows ISD demolition permits, not Historical Commission cases, so it cannot show how many buildings were delayed or how long the delay added. The demolition page lists no fees. A "close" date in our data is when ISD closed the permit, which for a tear-down often follows the replacement house. Licenses are not matched in our Cambridge file; see Cambridge contractor license lookup.
How we know this
Rules are quoted from the Cambridge Historical Commission's Demolition Delay, Application Forms and Mid Cambridge NCD pages, read 23 October 2026. Permit counts are City of Cambridge Inspectional Services permits on homes, October 2023 to September 2026.
Numbers come from City of Cambridge Inspectional Services permits (the city's per-type open-data permit files), data through October 16, 2026. Nobody paid to be on this page and nobody can.
Questions
- What buildings are subject to demolition delay in Cambridge?
All buildings over 50 years old, city-wide. The Cambridge Historical Commission can confirm a building's construction date from its archives; email the Executive Director for an initial determination of significance before applying.
- How long is the demolition delay in Cambridge?
Up to twelve months for a building the Historical Commission finds significant and preferably preserved. The City Council extended it from six to twelve months in November 2019.
- Do I need Historical Commission approval to demolish a garage in Cambridge?
If it is over 50 years old, it goes through demolition review, but the Commission says utilitarian structures such as some residential garages generally need only staff review and sign-off, not a public hearing.
- Do I need approval for exterior work in a Cambridge conservation district?
Yes, a certificate first. In the Mid Cambridge Neighborhood Conservation District, the Commission says one of three certificates (non-applicability, appropriateness or hardship) is always needed to get a building permit. Interior work, work not visible from a public way and in-kind work generally get a Certificate of Non-Applicability from staff.
- Does a Cambridge Historical Commission approval expire?
Yes. The Commission says all its regulatory approvals have a life of six months; the Chair may extend one by six months, otherwise you reapply.
Build your own list
Every firm with that kind of permit on record. Pick what you value. The list moves.
Related guides
- Do I need a demolition permit in Austin? The 45-year historic review, the pre-demolition inspection and neighbor notice
- Boulder's demolition review for houses over 50 years old: what counts as demolition, the fees, and the 180-day stay
- Do I need a demolition permit in Cleveland? Yes: the project review, the $50 minimum fee, drawings, and what demolition firms charge
- Tearing down a house in Denver: the 40% rule, Landmark Preservation review, and the 21-day posting
- Do I need a remodel permit in Detroit? Building permits, who can do the work, fees and 7,119 permits
- Do I need an electrical permit in Eugene? Permanent wiring, owner permits, 2026 fees and 5,835 permits
For one city
- Demolition Delay — Cambridge Historical Commission (accessed 2026-10-23)
- Application Forms — Cambridge Historical Commission (accessed 2026-10-23)
- Mid Cambridge Neighborhood Conservation District — Cambridge Historical Commission (accessed 2026-10-23)