ADU Regulations:
Medford

Regulations Snapshot

Rear and Side setbacks: 3 feet
Building Separation: 10 feet
Height: 35 feet

Stormwater management: Yes, depending on amount of impervious area
Sprinkler system: Yes, see below for details
Separate utilities required: No
Impact Fees: None listed

Building Constraints

Number of ADU’s allowed on a single family lot

One

Maximum square footage of an ADU (detached or attached)

The maximum floor area of an ADU shall not exceed 900 square feet, or 50% of the total gross floor area of the principal dwelling unit, whichever is smaller.

Maximum Height

35 feet (same as primary home)

Maximum lot coverage

Can't be more than 25% of rear yard ( all area behind the house)

Exterior appearance requirements

Congruent with primary house

Setbacks

Rear setback

3 feet

Side setback

3 feet

Front setback

Same as primary house

Distance between buildings

10 feet

Parking

Parking requirement for an ADU

Each ADU requires one off-street parking space in addition to what is required for the primary dwelling. No parking space is required for an Accessory Dwelling Unit on a Lot if any portion of such Lot is located within a 0.5-mile radius of a Transit Station.

Where can the parking be located : Parking requirement for primary dwelling

Typically two off-street parking spaces

Additional Requirements

Separate utilities required

No, they can connect to the primary house

Stormwater management required

Yes, the size of the system is linear with the amount of impervious area created by the ADU (this can add $15k – $20k to the project)

Site plan review required

No

Town impact fees

None listed

Fire safety requirements

Not needed if less than 50 feet from the sidewalk. If more than 50 feet then a 20′ wide access path is needed. If not, a sprinkler system is required.

Soils report required

No, the building department will inspect the hole prior to construction of the foundation

Civil plans required

Yes

Short term rental allowed

No

Possible overlay districts

Historic, wetland, conservation land

ADUs on multifamily lots

Allowed