Massachusetts building departments

How permitting works in Massachusetts

Statewide 780 CMR, local building officials. Massachusetts uses one state building code, 780 CMR, and local building departments enforce it. Most residential contractors must be registered as home improvement contractors, and supervisors of structural work need a construction supervisor license.

A county name is only a geographic starting point. Depending on the address, a city, town, borough, township, or county office may issue your permit. How to check who issues your permit.

Massachusetts building codes and licensing

Residential code

780 CMR 10th Edition, Chapter 51 Massachusetts Residential Code (2021 IRC with MA amendments); effective Oct. 11, 2024, sole code since July 1, 2025

Commercial code

780 CMR 10th Edition base volume (2021 IBC with Massachusetts amendments); sole code in effect after the concurrency period ended June 30, 2025

Adopted by

Massachusetts Board of Building Regulations and Standards (BBRS) (opens in a new tab)

Contractor licensing

Contractors working on existing owner-occupied homes of 1 to 4 units must register as Home Improvement Contractors (HIC). Structural work, new construction, decks, and additions also require a Construction Supervisor License (CSL); the two are not interchangeable. Office of Consumer Affairs and Business Regulation (HIC) / Office of Public Safety and Inspections (CSL) (opens in a new tab)

What is different in Massachusetts

• One- and two-family homes and townhouses of three stories or less fall under the Residential volume (Chapter 51); all other buildings use the Base volume of 780 CMR.
• An HIC registration alone covers only ordinary repairs such as exterior painting, wallpapering, and repairing existing decking; building a deck or an addition requires a CSL.
• The contractor who signs the contract with the homeowner must hold the HIC registration, though CSL-required work can be subcontracted to a licensed and registered firm.
• Massachusetts amends the 2021 I-Codes heavily. The online amendments are unofficial copies; the official text is sold through the Secretary of the Commonwealth's State Bookstore.

Massachusetts department guides

Browse Massachusetts counties

Bold counties have at least one researched department guide.

Planning a project in Massachusetts?

Start with what the model codes say, then confirm local rules with the department that serves your address.

• Do I Need a Permit for a Deck
• Do I Need a Permit for a Fence
• Do I Need a Permit for a Shed
• Do I Need a Permit to Replace a Roof
• Do I Need a Permit to Replace a Water Heater
• Do I Need a Permit for a Kitchen Remodel
• How Much Does a Building Permit Cost
• Building Inspection Stages Explained

Sources

1. Massachusetts Board of Building Regulations and Standards
2. Mass.gov – Tenth edition of the MA State Building Code 780
3. Mass.gov – HIC Contractor Resources

State facts checked October 21, 2026. Local amendments can change these rules; the department serving your address has the final word.