Sandwich, MA

Sandwich, MA Accessory Dwelling Unit (ADU) Rules

City Acceptance Rating:
4/10 (10 is most accepting)


What you need to know 

Sandwich draws a distinction between “Accessory Dwelling Units” and “Accessory Apartments” and provide different rules for each.

The Difference:

“Accessory Dwelling Unit”: These are allowed by special permit and MUST be rented as affordable housing.

“Accessory Apartment”: These are allowed by right and CANNOT be rented to anyone.


Rules for “Accessory Apartments” (not rentable)

They are allowed by right in the following districts:

  • R-1

  • R-2

  • VIL

  • BL-1

  • B-2

  • RD

  • S

Construction rules

  • The ADU can only have 1 bedroom and must be 800SF or less.

  • The lot must be at least 10,000SF. For cluster developments, the average density of the lots must be at least 10,000SF.

  • ADUs are not allowed on properties subject to a Comprehensive Permit, an Affordable Housing Conditional Density Special Permit or an Accessory Dwelling Unit Special Permit.

  • A detached ADU must be no more than 80 feet from the primary dwelling.

  • Additions must meet all applicable front, side and rear setbacks, height and lot coverage requirements.

  • At least one additional off-street parking space shall be provided. Separate driveways are prohibited.

  • Accessory apartment are only allowed on single-family lots.

  • Only 1 ADU is allow per lot.

  • One of the two dwelling units must be owner occupied year round.

  • The ADU cannot be rented. They are prohibited from any use as rental units on a yearly, monthly, weekly or daily basis.

Accessory Dwelling Unit Rules:

If you are interested in creating an Accessory Dwelling Unit to add to Sandwich’s affordable housing stock please contact us directly. There are separate rules for these units and special financing/grant opportunities available through the state and local municipalities.

See the full text here: Zoning Ordinance Section 4115. By-Right Accessory Apartment