Cambridge, MA Accessory Structures: Shed & Carport Rules (2026)

h provides that 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, tying a shed, detached garage, or similar structure's placement directly to the same front, side, and rear setback distances that apply to the principal building in that district rather than a separate, looser accessory-structure setback. k then adds a height cap: an accessory building in Residence C-1 and Office-1 districts shall not exceed fifteen feet in height above the ground level.

j bars using a dwelling or mobile home as an accessory building outright, except in an Industrial District for a night watchman or janitor's quarters, or where the structure independently qualifies as an Accessory Apartment. 30, so a shed cannot be enlarged into a guest cottage without satisfying the same lot-area, setback, and floor-area-ratio rules as new construction. 50 and Board of Zoning Appeal-approved research accessory uses. A shed that meets the setback and 15-foot height limit is built under an ordinary building permit; exceeding either figure requires a redesign or a variance from the Board of Zoning Appeal under Article 10.