How long is a building permit good for in Massachusetts?

Massachusetts has one building code, 780 CMR, and since 1 July 2025 only its tenth edition applies; the base volume governs most buildings and its chapter 51, the Massachusetts Residential Code, governs detached one- and two-family homes and townhouses of three storeys or fewer (tenth edition overview, mass.gov). Both volumes carry the same expiration section. Section 105.5 of the base volume says every permit "shall become invalid unless the work on the site authorized by such permit is commenced within 180 days after its issuance, or if the work authorized on the site by such permit is suspended or abandoned for a period of 180 days after the time the work is commenced" (780 CMR chapter 1). Section R105.5 of the residential code says the same in the same words (780 CMR 51.00 chapter 1).

Two clocks, then: one that starts the day the permit issues and runs 180 days until work begins, and one that starts whenever work stops and runs 180 days until it resumes. A permit that has been open for two years is still valid if the work never paused for 180 days.

The same section gives the building official the power to grant, in writing, "one or more extensions of time, for periods not more than 180 days each" (780 CMR 105.5). Three conditions are written into it: the request is made in writing, it is made before the 180-day expiration date, and it demonstrates justifiable cause. The code does not say what counts as justifiable cause; that judgment is the building official's, and it is the reason a request filed the week after a permit lapsed is on weaker ground than one filed the week before.

Towns describe the practice in their own words. Milton's inspectional services FAQ says work must begin within six months of issuance and then "continue at a reasonable pace toward completion", that a permit or application inactive for six months or more can be deemed expired, and that the department evaluates each case and accommodates justified delays where the codes have not changed in the meantime (Milton FAQ). Mashpee's FAQ says construction must begin within six months of issue, that a one-time six-month extension can be requested from the building department, and that if work has not started by the end of that extension the permit expires and a new application must be submitted for approval by every department (Mashpee FAQ). Six months is the towns' shorthand for the code's 180 days.

An application that is filed but not pursued also dies. Section 105.3.2 deems an application abandoned 180 days after the date of filing "unless such application has been pursued in good faith or a permit has been issued", and here the building official's extensions are shorter: one or more periods of not more than 90 days each, again on a written request with justifiable cause (780 CMR 105.3.2; R105.3.2). On the department's side, section 105.3.1 requires the building official to examine the application and issue or deny the permit in writing within 30 days of filing, and says that failing to act within 30 days can be the subject of a complaint to the official's appointing authority or the Building Official Certification Committee, or an appeal (780 CMR 105.3.1).

An invalid permit is no permit. Section 105.1 makes it unlawful to construct, reconstruct, alter, repair, remove or demolish a building, change its use, or install regulated equipment "without first filing an application with the building official and obtaining the required permit" (780 CMR 105.1), so work that continues after the permit has become invalid is work without a permit. The route back is a new application, as Mashpee's FAQ states for its own permits, and a new application is reviewed under the code in force when it is filed: since 1 July 2025 that is the tenth edition (mass.gov).

The building official can also end a permit early. Section 105.6 authorizes suspending or revoking a permit that was issued in error, on incorrect, inaccurate or incomplete information, or in violation of an ordinance, regulation or the code itself (780 CMR 105.6).

The permit, or a copy, must stay on the site until the project is complete (section 105.7), and the building official may require at least one business day's notice before work starts (105.8). Required inspection points are listed when the permit is issued; the official may designate points that need one business day's notice from the contractor, and must make the inspection within two business days of being notified (110.3). Work must remain accessible and exposed until it is inspected and approved (110.1). None of these is a wait time we can promise: they are what the code requires of the two sides (780 CMR chapter 1; 780 CMR 51.00 chapter 1).

The 180-day rule above is the building permit's. Electrical, plumbing and gas work is permitted under the specialized codes named in M.G.L. c. 143, § 96, each permit issued to the licensed electrician or plumber or gas fitter who does the work, not to the homeowner (electricians consumer fact sheet; plumbers and gas fitters consumer fact sheet). Those codes set their own timing, and the licensee who pulled the permit is the person to ask about it. Plumbing and gas fitting permits run on a shorter clock than the building permit: under 248 CMR 3.05(1)(e) they are invalid if work is not started within 90 days of the date of the permit, unless the holder can show that the failure to start was beyond their control (248 CMR 3.00). A building permit that expires does not change the status of a trade permit on the same job, and the reverse is also true.