Before You Build in Cambridge, MA: Permit & Rule Checklist (2026)

Cambridge pools deeper than 24 inches require a 48-inch barrier with self-closing, self-latching gates, per Massachusetts State Building Code 780 CMR Section 3109.

Massachusetts Fence Law (MGL Chapter 49) governs boundary fence disputes; Cambridge adds local spite-fence protections under MGL c.140 s.162 prohibiting malicious 6-foot-plus fences.

Cambridge requires a building permit for most fences from Inspectional Services; permit fees are based on linear footage and height, with review typically taking 2 to 3 weeks.

Retaining walls over 4 feet tall in Cambridge require engineered drawings and a building permit; walls over 2 feet count toward fence height if topped by a fence.

Cambridge limits residential fences to 6 feet in side and rear yards and 4 feet in front yards; taller fences require a special permit from Inspectional Services.

Cambridge requires building and plumbing permits for new pools through Inspectional Services, with zoning review for setbacks and compliance with the Massachusetts State Building Code.

Pool barriers in Cambridge must be at least 4 feet tall with self-closing and self-latching gates per the Massachusetts State Building Code and International Swimming Pool and Spa Code.

Cambridge pools must comply with state safety rules including anti-entrapment drain covers, proper electrical bonding, and barrier alarms, with local health inspection for semi-public pools.

Above-ground pools deeper than 24 inches in Cambridge require permits and barrier compliance, with ladders that are removable or lockable when the pool is unattended.

Hot tubs and spas in Cambridge require electrical permits and must have a locking safety cover meeting ASTM F1346 to satisfy barrier requirements.

Garage conversions to living space are permitted in Cambridge with full building permits. Under the 2024 MA Affordable Homes Act, converting a garage into an ADU is allowed by right in most zones.

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.

Carports in Cambridge are accessory structures subject to zoning setbacks and a building permit over 120 sq ft. They are uncommon on dense lots and historic districts often restrict open-wall designs.

Tiny homes on foundations are allowed as ADUs in Cambridge under MGL c.40A s.3A. Tiny homes on wheels are treated as recreational vehicles and cannot be used as permanent dwellings under the MA State Building Code.

Cambridge requires a building permit for any shed over 120 sq ft and zoning compliance for smaller sheds. Setbacks of 3 to 5 feet apply, with extra review in historic districts.

Cambridge allows only small recreational fires in approved portable devices under 527 CMR 1.00. Permits from Cambridge Fire are required for most outdoor burning given the citys density.

Open burning is prohibited year-round in Cambridge. The state burn season under 310 CMR 7.07 (Jan 15 to May 1) excludes densely populated cities, so no residential brush burning is allowed.

Cambridge runs its own water supply from Fresh Pond and Hobbs/Stony Brook reservoirs. The city imposes odd/even watering limits during drought and can escalate to full non-essential use bans.

Cambridge requires a permit to remove any tree 6 inches DBH or larger under the 2021 Tree Protection Ordinance. Removals require replacement planting or payment into the Cambridge Tree Fund.

Cambridge has one of the strictest tree ordinances in MA. Under the 2021 Tree Protection Ordinance, major trimming of any tree 6 inches DBH or larger requires a permit from the city arborist.