Sandwich, MA
Sandwich, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10 (10 is most accepting)
Last updated: 4.29.2024
What You Need to Know
Sandwich distinguishes between Accessory Dwelling Units and Accessory Apartments. Accessory Apartments are geared towards family member use and cannot be rented, whereas, an Accessory Dwelling Unit is geared towards providing affordable housing to the community.
Type of ADU Permit Required
An Accessory Apartment is by right
An Accessory Dwelling Unit requires a special permit
ADU Rules
Accessory Apartments
Cannot be greater than 800 gross SF or contain more than one bedroom (although it can have an office).
In Sandwich, gross square footage is defined as the total floor area of the dwelling (excluding the basement, attic, garage, hallways, and closets)
Lots must have an area of at least 10,000 square feet for an accessory apartment to be allowed. Or, for lots created as part of a cluster special permit, the 10,000 square foot minimum/unit applies to the overall density of the cluster development.
Depending on the density of the development, accessory apartments are not allowed in single family dwellings that are subject to a comprehensive permit, an affordable housing conditional density special permit or an accessory dwelling unit special permit.
Limited to one bedroom.
If the accessory apartment is in an accessory structure, it may not be further than 80 feet from the primary dwelling.
The apartment may be located in the primary dwelling (conversion of existing space or an addition).
If the accessory apartment is located in the primary dwelling, all setbacks, height, and lot coverage requirements must be met.
At least one additional off-street parking space must be provided and a separate driveway is not allowed.
A maximum of one additional accessory apartment is allowed to be constructed in the primary residence and accessory apartments are not allowed on lots where there are more than one single-family, one or more two-family or one or more multi-family dwelling units.
The owner of the primary residence must live in either the primary residence or accessory apartment
Accessory apartments may not be used as rentals for any period of time.
Accessory Dwelling Units (ADUs)
One ADU permitted per lot under a special permit.
ADUs are not allowed on lots less than 40,000 square feet
ADUs cannot be greater than 1,000 square feet or 30% of the gross square footage of the primary residence.
The ADU must be attached or within the primary residence.
ADUs must be compatible aesthetically with the surrounding area.
Two off-street parking spaces must be available for the ADU.
Existing septic systems can be used only with approval from the Board of Health.
The principal owner of the property must live at least 8 months a year in the primary residence or ADU.
Resources: https://www.sandwichmass.org/DocumentCenter/View/719/Zoning-By-Law-November-2017-PDF