Accessory Structures in Cambridge, MA (2026)
2 verified accessory structures rules for Cambridge, Massachusetts, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Cambridge allows accessory dwelling units by right under the 2024 MA Affordable Homes Act and MGL c.40A s.3A, the statewide ADU mandate. Most residential districts now permit one ADU by right.
Cambridge ADU Rules
Few RestrictionsMass. Gen. Laws ch. 40A, § 3 (Zoning Exemptions — Accessory Dwelling Units)
No zoning ordinance or by-law shall prohibit, unreasonably restrict or require a special permit or other discretionary zoning approval for the use of land or structures for a single accessory dwelling unit, or the rental thereof, in a single-family residential zoning district; provided, that the use of land or structures for such accessory dwelling unit under this paragraph may be subject to re...
Shed & Carport Rules
In Cambridge's Residence C-1 zoning district, an accessory building such as a shed or garage cannot sit closer to any lot line than the district's minimum setback, and in Residence C-1 and Office-1 districts it cannot rise above 15 feet, per Zoning Ordinance Sections 4.21.h and 4.21.k.
Cambridge Accessory Building Setback and Height
Some RestrictionsCambridge Zoning Ordinance Sec. 4.21.h and Sec. 4.21.k, Supp. No. 8
h. In Residence C-1 Districts an accessory building shall not be located nearer to any lot line than the minimum setback in the zoning district. ... k. An accessory building in Residence C-1, and Office-1 districts shall not exceed fifteen (15) feet in height above the ground level.