Somerville Zoning & Land Use Guide
Key Zoning Facts
Somerville Zoning Overview
Somerville is one of the most densely populated cities in the United States, located immediately northwest of Boston. The city adopted a comprehensive zoning overhaul that replaced its decades-old ordinance with a modern, form-based code. This new ordinance emphasizes neighborhood character, transit-oriented development, and housing production, organized around the city's distinct squares and corridors.
The opening of the MBTA Green Line Extension through Somerville has fundamentally changed the city's development landscape, bringing rapid transit to neighborhoods that previously lacked it. Zoning around the new stations allows significantly higher density and mixed-use development, attracting substantial investment to areas like Union Square and East Somerville.
Somerville was an early adopter of ADU-friendly policies in Massachusetts, and the 2024 state ADU law reinforces the city's existing framework for allowing accessory dwelling units.
Key Zoning Districts
Somerville's modern zoning code includes Neighborhood Residential (NR), Urban Residential (UR), Mid-Rise (MR), Commercial Core (CC), and Fabrication (FAB) districts. Each district has specific form-based standards addressing building height, setbacks, and ground-floor activation. Transit-area overlay districts near Green Line stations allow the highest intensities.
ADU Regulations
Under the 2024 state ADU law, Somerville allows ADUs by right in residential zones. ADUs may be up to 900 square feet with no additional parking required. Somerville's zoning already incorporated ADU provisions, and the state law broadened eligibility to all single-family properties.
Development Process
Development in Somerville begins with a zoning review through the Planning and Zoning Division. Conforming projects proceed to the Inspectional Services Department for building permits. Projects requiring zoning relief apply to the Zoning Board of Appeals. Large projects may require Planning Board site plan review with public hearings.
Regulatory Layers That Apply in Somerville
Your property is subject to ALL of these regulatory layers. Each one can impose additional requirements beyond the others.
Federal
- FEMA Flood Zones: Applicable
- View FEMA Flood Map
State — Massachusetts
- Building Code: MA State Building Code (780 CMR, based on 2021 IBC)
- State ADU Override: Yes (MA ADU Law (2024) — requires single-family zones to allow ADUs by right)
County — Middlesex County
- Role: Property records, tax assessment, unincorporated area planning
City / Municipal
The city's zoning ordinance, building codes, and local permits form the primary layer of land-use regulation for your property.
Overlay Districts
No overlay districts identified.
Private Restrictions
- HOA / CC&Rs common: Yes
- Check HOA CC&Rs for additional restrictions.
Primary Zoning Districts
- Min Lot
- 3,000 sq ft
- Max Height
- 35 ft
- Front Setback
- 10 ft
- Side Setback
- 6 ft
- Rear Setback
- 20 ft
- Min Lot
- 2,500 sq ft
- Max Height
- 55 ft
- Front Setback
- 5 ft
- Side Setback
- 5 ft
- Rear Setback
- 15 ft
- Min Lot
- None
- Max Height
- 65 ft
- Front Setback
- 0 ft
- Side Setback
- 0 ft
- Rear Setback
- 10 ft
ADU Rules in Somerville
- Max Size
- 900 sq ft
- Max Height
- 20 ft
- Rear Setback
- 5 ft
- Side Setback
- 5 ft
- Parking
- No additional parking required
- Owner Occupancy
- Not required under state ADU law
- Permit Timeline
- 60-90 days
Permit Costs & Timelines
Permit Costs & Timelines
Specific permit fee schedules for Somerville are available from the local planning department. Fees vary based on project type, scope, and valuation.
Check Somerville permit fees →