City Building Permits

Cambridge, MA Building Permit Guide

How to apply for a building permit in Cambridge, Massachusetts. Permit authority, application steps, fees, and inspection requirements.

Massachusetts Middlesex County Updated March 2026

Permit Authority

All properties within the City of Cambridge.

Department
Inspectional Services Department
Address
831 Massachusetts Avenue, Cambridge, MA 02139
Phone
617-349-6100
Website
https://www.cambridgema.gov/inspection

Online Permit Portal

Open OpenGov

Platform: OpenGov • Account required: Yes • Submission: Online only

Application Process

  1. Submit application through the OpenGov portal or in person at 831 Massachusetts Avenue.
  2. Provide required affidavits (Estimated Cost of Construction Affidavit, Homeowner's Affidavit if applicable, or contractor documentation).
  3. Application reviewed for completeness; plan review conducted where required.
  4. Applicant notified of approval and invoiced for permit fees.
  5. Pay fees; permit card issued.
  6. Post permit card visibly at job site before work commences.
  7. Schedule required inspections through the department.

Typical processing time: Not published; contact department at 617-349-6100 for current timelines.

Source: Inspectional Services Department

General Requirements

A building permit is required prior to constructing, altering, repairing, or demolishing any structure.

Required Documents

  • Completed permit application
  • Estimated Cost of Construction Affidavit
  • Homeowner's Affidavit (if applicable)
  • Contractor documentation (if applicable)
  • Plans and supporting documents as required
Permit validity
Work must commence within 6 months of permit issuance; work must be completed within 2 years (standard Massachusetts provision; verify with department).
Building code
780 CMR 9th Edition (transitioning to 10th Edition effective July 1, 2025)
Owner-builder
Owner-builders may act without a CSL for their own single-family residence.
Contractor requirements
All work must comply with 780 CMR. Licensed contractor (CSL) required; Home Improvement Contractor (HIC) registration additionally required for residential work on 1-4 unit owner-occupied properties.

Fees

Minimum permit fee
$50
Plan check fee
$100 included in the building permit fee
Permit fee formula
Residential (3 units or fewer): $15.00 per $1,000 of construction cost (or fraction thereof); Commercial / all other: $20.00 per $1,000 of construction cost (or fraction thereof)
Trade permit fee
Included in building permit
Reinspection fee
$25 to $100 depending on violation type
Penalty (no permit)
Triple the standard fee for work commenced without permit
Payment note
Permit fees are invoiced after approval; payment is required before the permit is officially issued.

Fees change. Verify current amounts at the official fee schedule (effective January 1, 2024).

Work That Does NOT Require a Permit

  • Ordinary repairs to structures that do not affect structural elements, egress, fire protection systems, fire ratings, energy conservation, plumbing, gas, electrical, or other utilities
  • One-story detached accessory structures (tool sheds, playhouses, etc.) not exceeding 120 sq ft
  • Retaining walls not exceeding 4 feet in height measured from footing bottom to top
  • Water tanks on grade with capacity not exceeding 5,000 gallons and height-to-diameter ratio not exceeding 2:1
  • Sidewalks and driveways not more than 30 inches above adjacent grade, not over basement space, and not on an accessible route
  • Painting, wallpapering, tiling, carpeting, and similar finish work

Important: Plumbing, electrical, and gas work within otherwise exempt projects may still require trade permits. Confirm all edge cases with the Inspectional Services Department.

Inspections

How to Schedule

Scheduling deadline
Contact department for scheduling.
Inspection hours
Monday 7:00 AM - 6:00 PM; Tuesday through Thursday 7:00 AM - 3:30 PM; Friday 7:00 AM - 12:00 PM

Typical inspection sequence: Typical sequence for residential projects: Foundation / footing inspection (before pouring); Framing inspection (before insulation or wallboard); Insulation inspection (if applicable); Final building inspection. Trade inspections (electrical, plumbing, gas, mechanical) are coordinated separately with respective inspectors.

Additional Resources

Information on this page was last verified: March 2026. Permit rules and fees change — confirm current requirements directly with the Inspectional Services Department before applying.

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Important: This page is an educational resource provided by jaspector.com. It is not legal advice, and it does not substitute for official guidance from the permit authority listed above. Permit requirements, fees, and processes change frequently. Always verify current requirements directly with the issuing department before beginning any construction project. Use of this page does not create an attorney-client relationship. Jaspector assumes no liability for any outcomes arising from reliance on this information.

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