ADU Rules in Medford, MA

Medford follows the Massachusetts state baseline with local regulations.

Data verified as of March 2, 2026
State Baseline Only — Local Details Not Yet Researched

State Baseline Only

This page uses Massachusetts state baseline rules. Local setbacks, height limits, and other dimensional standards may vary. Contact your local building department for specifics.

MA

State Baseline: Affordable Homes Act

Up to 900 sq ft or 50% of principal dwelling (whichever is smaller). By-right approval statewide.

Zoning Districts

RESDefault Residential

Default residential zone (state baseline only — specific district not yet researched)

Default Zone
TypeApprovalMax SizeHeightParkingOwner Occ.
Detached ADU
By Right
900 sq ft1 spaceNo
Attached ADU
By Right
900 sq ft1 spaceNo
Interior Conversion
By Right
900 sq ftNoneNo

Transit Stations

Properties near transit stations may qualify for parking exemptions.

Ball Square

LIGHT RAIL

Medford/Tufts

LIGHT RAIL

Wellington

SUBWAY

West Medford

COMMUTER RAIL

Building Department

Medford Building Department

85 George P Hassett Dr # 115A, Medford, MA 02155, USA

Phone: (781) 393-2509

Visit Website →

Frequently Asked Questions

Are ADUs allowed by right in Medford, MA?

Yes. ADUs in Medford are approved by right — you submit your plans to the building department and receive a building permit without a public hearing or special permit process. This is guaranteed by the Affordable Homes Act.

What types of ADUs can I build in Medford?

Medford allows detached, attached, conversion ADUs. With up to 900 sq ft allowed, a detached ADU gives you the most flexibility for a full living space.

Do I need to live on the property to build an ADU in Medford?

No. Medford does not require owner occupancy — this is a right guaranteed by the Affordable Homes Act. You can rent both your main home and the ADU, making this a pure investment property if you choose.

How big can I build an ADU in Medford, MA?

In Medford, you can build an ADU up to 900 square feet or 50% of your home's living area, whichever is larger. With 900 sq ft, you have enough room for a full 2-bedroom cottage with a kitchen, bathroom, and living area. This is guaranteed by the Affordable Homes Act.

Does Medford have historic district rules for ADUs?

Yes. Medford has historically significant areas including Medford Historical Society, Pleasant Street Historic District, Town of Winchester Water Department Historic Site, Winchester Center Historic District. If your property is in or near a historic district, your ADU design may require review by the local historical commission for architectural compatibility. This can affect timelines and design choices.

Can I rent out my ADU in Medford?

Yes, long-term rentals are allowed for ADUs in Medford. However, short-term rentals (like Airbnb) are not currently allowed for ADUs. With a population of 59,126, Medford has strong rental demand.

How accurate is the ADU data for Medford?

The information on this page reflects Massachusetts state baseline rules under the Affordable Homes Act. Medford may have additional local requirements that differ from the state baseline. We recommend confirming with your local building department before starting your project.