Frequently Asked Questions

  • When is a building permit required?

    Anyone seeking to construct, alter, or demolish a structure or install a sign must first obtain a building permit from a building inspector at the Inspectional Services Department. The building permit must be obtained before the start of any work and must be prominently posted at the job site.

  • Who can be issued a building permit?

    Building permits are issued to construction supervisors licensed by the City of Cambridge or the State of Massachusetts. The State license is only valid for work involving structures of less than 35,000 cu. Ft. As an exception to this requirement, building permits are also issued to homeowners doing work on one or two unit dwellings where they reside or intend to reside. It is noted that when homeowners are issued building permits, they may be liable for contractors working on their property and they are not eligible for protection under the provisions of the Homeowners Improvement Contractor Law. For these reasons, ISD encourages homeowners to have the building permit taken out by a properly licensed contractor.

  • What about the issuance of plumbing, gas, or wiring permits?

    These permits are issued to Massachusetts licensed plumbers, gasfitters, or electricians. Permits are issued in accordance with Massachusetts General Laws (MGLs); MGL 143-3L in the case of wiring permits and MGL 142-13 in the case of plumbing and gas permits.

  • What requirements must be met prior to applying for a building permit?

    The work must be in compliance with the Cambridge Zoning Ordinance. Also, structures located in historic districts, neighborhood conservation districts, designated as landmarks, or subject to preservation restrictions require approval from the Cambridge Historical Commission. Also, structures over 50 years old cannot be demolished without Historical Commission approval. For the larger construction projects, approvals may also be required from the Community Development, Public Works, Traffic/Parking/Transportation, and Fire Departments.

  • What other permits would be required before a building permit could be issued?

    If a new or expanded curb cut is required for the project, it is necessary to obtain City Council approval before the building permit can be issued. Application forms are available at the Inspectional Services and Public Works Departments for curb cuts.

  • When must work be started under the building permit?

    Work must be started within six (6) months of the date the permit is issued. Once started, the work must be progressed continuously to completion. The City Noise Ordinance does not permit construction activities prior to 7:00 a.m. (9:00 a.m. on Saturdays and holidays) and after 6:00 p.m. Sunday work is not permitted.

  • What about access requirements for persons with disabilities?

    The Massachusetts Architectural Access Board Regulations are part of the Building Code and are enforced by ISD for new construction, alterations, and changes in use.

  • Do I need a building permit to install a shed?

    If the shed is less than 120 square feet, a building permit is not required. However, one must comply with the provisions of the Zoning Ordinance for any size shed.

  • What is the required height of guardrails and handrails?

    For single or two family houses, a deck located more than 30 inches above grade must have a guardrail of at least 36 inches in height. Handrails must be located at a height of from 30 inches to 38 inches. If the guardrail also serves as the handrail for open sided steps, the minimum height is 34 inches. Guardrails for uses other than 1 or 2 family structures must be a minimum if 42 inches.

  • How many layers of roofing are allowed to remain when re-roofing?


  • Can ISD recommend a contractor, architect, or attorney?