Massachusetts Building Code, Permitting and Inspection
Massachusetts Building Code
The Massachusetts State Building Code is 780 CMR. It is not a stand-alone document: it adopts national model codes (primarily the International Building Code and International Residential Code families) and then amends them with Massachusetts-specific provisions. The code is administered by the Board of Building Regulations and Standards (BBRS), which publishes editions, hears appeals, and licenses Construction Supervisors. Massachusetts is on the 10th edition (2021 I-Code base); confirm the edition in force and check local amendments, because cities and towns may adopt stricter local requirements.
Key concepts: one- and two-family dwellings and townhouses follow the residential provisions of 780 CMR; everything else follows the commercial volume and its use/occupancy, type-of-construction, height-and-area and egress chapters. Accessibility in Massachusetts is governed by 521 CMR (Architectural Access Board), which is separate from and sometimes stricter than the federal ADA - a classic exam trap. Another trap: the Construction Supervisor License. A CSL (unrestricted, or restricted to one- and two-family) is required to supervise most building work, and hiring an unlicensed supervisor is a violation even if the crew is skilled.
The building official has broad authority to interpret, to require engineered documentation, and to accept alternate materials or methods only on evidence that the alternate is equivalent in quality, strength, effectiveness, fire resistance, durability and safety. Work must conform to the approved plans; field changes require approval before concealment.
Rule of thumb: when a question asks who decides, the answer is almost always the local building official, with the BBRS on appeal - not the contractor or another trade's inspector.
Permitting and Inspection
Almost every project needs a building permit before work begins: new construction, additions, structural alterations, decks, roofing where sheathing is replaced, pools, sheds over the code threshold, demolition, and changes of use. Ordinary repairs - painting, and minor work that does not affect structure, means of egress or fire resistance - are typically exempt. Pulling the permit is the owner's legal act, but the contractor usually files as agent; for home improvement work the application must show the Home Improvement Contractor (HIC) registration number, a CSL number, and proof of workers' compensation insurance.
Before the building permit, screen for companion approvals: zoning (setbacks, height, lot coverage - verify against the plot plan), conservation commission under the Wetlands Protection Act if work falls inside a 100-foot buffer zone, board of health for septic or well, historical district, and any special permit or variance. Missing one of these is the most common cause of a stalled job.
Inspection sequence is a chain: excavation/footing, foundation, waterproofing and drainage before backfill, framing including sheathing and fireblocking, rough plumbing, rough electrical, rough mechanical, insulation and air sealing before drywall, then final building, electrical, plumbing and mechanical, and a certificate of occupancy before occupancy. Cardinal rule: never conceal work before it is inspected and approved. Inspectors may require 24 hours' notice - verify locally.
Traps: starting before the permit (stop-work order plus doubled fees), assuming one permit covers a different scope, letting a permit lapse through inactivity, and skipping the final inspection and CO.