ADU Rules in Lowell, Massachusetts

Lowell is a Middlesex County Gateway City with a population of about 115,000, located at the confluence of the Merrimack and Concord rivers. One of America's first planned industrial cities, Lowell is home to Lowell National Historical Park preserving the 19th-century textile mill canal system. UMass Lowell is a major employer and educational institution. Massachusetts enacted a statewide ADU law (Chapter 150, Acts of 2024) requiring ADUs by right in single-family zones.

Massachusetts Statewide ADU Law (2024)

Massachusetts Chapter 150, Acts of 2024 requires municipalities to allow ADUs by right in single-family residential zoning districts. Verify how Lowell has implemented this law.

Lowell Zoning Ordinance

The City of Lowell Zoning Ordinance governs land use in Lowell city limits.

Permitted ADU Types

Per Massachusetts ADU law and Lowell zoning (verify current standards):

• Basement and interior conversions: Common in Lowell's multi-story residential housing
• Attached ADUs: With separate entrance
• Detached ADUs: In rear yards of eligible zones

Size Limits

Per Massachusetts ADU law:

• ADU cannot exceed smaller of: primary dwelling or 900 square feet

Setbacks

Per Lowell residential zone:

• Rear: Minimum setback
• Side: Minimum setback

Historic Districts and National Park

Lowell has a National Historical Park and local historic districts. Properties near or within the historic mill district may require review by:

• National Park Service: For properties within the NHP boundary
• Lowell Historical Commission: For locally designated historic properties

Merrimack River Flood Zones

Parts of Lowell near the Merrimack and Concord rivers may be in FEMA flood zones. Verify flood map status.

Massachusetts Wetlands Protection Act

Properties within 100 feet of wetlands or 200 feet of rivers are subject to the Massachusetts Wetlands Protection Act. Lowell Conservation Commission review required.

UMass Lowell

UMass Lowell creates demand for rental housing. The campus is a state institution with separate permitting. Surrounding residential areas use Lowell's Zoning Ordinance.

Permit Process

1. Verify zoning and state ADU law: Lowell Division of Planning and Development
2. Historic review: If near the National Historical Park or in a local historic district
3. Conservation Commission review: If near waterways or wetlands
4. Check flood zone: If near the Merrimack or Concord rivers
5. Submit plans: Lowell Building Department
6. Building permit and inspections
7. CO: Required before occupancy

Contact

City of Lowell Division of Planning and Development 375 Merrimack Street, 3rd Floor, Lowell, MA 01852 Phone: (978) 674-4144 Website: lowell.ma.us

Disclaimer: Massachusetts statewide ADU law (2024) requires ADUs by right in single-family zones. National Historical Park and historic district review adds complexity. Verify current standards before starting any project.