Wayland, MA
Wayland, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10
Last updated: 11.14.2024
Image source: Town of Wayland Facebook
What You Need To Know
Wayland, like all of Massachusetts since the passage of the 2024 Affordable Homes Act, allows ADUs by right. Each town has slightly different rules surrounding ADUs, but they all must adhere to the framework outlined by the state. The rules for Wayland are outlined below.
Type of ADU Permit Required
ADUs in Wayland do not require special permits, and can be built using a traditional building permit.
ADU Rules
ADU Rules in Wayland:
Wayland allows one ADU per lot by right. To build more than one ADU, a special permit must be approved through the town.
An ADU can be maximum 900 square feet, or half the Gross Floor Area of the main house; whichever is smaller.
ADUs may be attached or detached from the main house.
Short-term rentals are not allowed. The minimum rental time for ADUs is 31 days.
ADUs must have a separate entrance from the main house - attached ADUs can share an entry hall with the main house, but need a separate entry within the entry hall.
If the ADU is within 0.5 miles of a transit station, no additional parking is needed. If it is further than 0.5 miles from a transit station, one off-street parking spot must be added.
In addition to the by right ADU, Wayland, via special permit, allows for an Affordable Accessory Dwelling Unit. For more information on this path, please see the link below.
Resources:
Hingham, MA
Hingham, MA Accessory Dwelling Unit (ADU) Rules
Last updated: 12/1/2025
Image source: See Plymouth
What You Need To Know
Hingham, like all of Massachusetts since the passage of the 2024 Affordable Homes Act, allows ADUs by right. Each town has slightly different rules surrounding ADUs, but they all must adhere to the framework outlined by the state. The rules for Hingham are outlined below.
Type of ADU Permit Required
ADUs in Hingham do not require special permits, and can be built using a traditional building permit. Residents are allowed to build one ADU per lot.
ADU Rules
An ADU can be maximum 900 square feet, or half the Gross Floor Area of the main house; whichever is smaller.
ADUs may be attached or detached from the main house.
Short-term rentals are not allowed - the minimum rental term for an ADU in Hingham is 30 days.
Properties within ½ mile of a transit station do not require additional parking. Properties outside of that area require one additional off-street parking spot.
Attached ADUs must maintain the architectural style of the main house to the extent possible.
ADUs must have a separate entrance from the main house - attached ADUs can share an entry hall with the main house, but need a separate entry within the entry hall.
Exterior entrances must be on the side or back of the main house.
Exterior staircases above the first floor are only allowed on the back of an ADU, and only under special circumstances.
The main house and ADU must be owned by the same person(s).
Resources:
https://www.hingham-ma.gov/DocumentCenter/View/25969/2025-Hingham-Zoning-By-Law_Clean?bidId= (See pages 136-138 of PDF)
Stoneham, MA
Stoneham, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10
Last updated: 10.29.2024
Image source: Town of Stoneham
What You Need To Know
Currently not in compliance with the Massachusetts Affordable Homes Act.
A single ADU is allowed with a permit on single-family home properties, must share a wall with the main structure and can not exceed 750 SF. Permits are not transferrable to new owners outside of the family.
Type of ADU Permit Required
ADUs require a special permit.
ADU Rules
Permit Filing: A Special Permit is required, filed with the Registry of Deeds, and can be amended or rescinded if ownership or conditions change.
Automatic Reversion: If ownership changes outside of the family, the property reverts to single-family use unless a new permit is applied for.
Size and Structure: The ADU cannot exceed 750 square feet and must share at least 75% of a wall with the main dwelling; utilities must be single-metered.
Parking: One additional parking space is required for the ADU, in addition to two spaces for the primary residence.
Occupancy Limit: ADU occupancy is limited to two people and cannot be used for commercial purposes.
Deed Restriction: A deed restriction confirming owner occupancy must be filed, and a Certificate of Occupancy requires proof of the permit’s recording.
Single Ownership: The main and accessory dwellings must be under the same ownership and cannot be separated. Only one ADU is permitted per lot.
Resources:
https://www.stoneham-ma.gov/DocumentCenter/View/1223/Ch15-Zoning-Part-1
Fairhaven, MA
Fairhaven, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10 (10 is most accepting)
Last updated: 9.19.2024
Image source: Fairhaven Visitors Center Facebook
What You Need To Know
Currently not in compliance with the Massachusetts Affordable Homes Act.
ADUs are only allowed by converting an existing space within a single-family dwelling.
Type of ADU Permit Required
ADUs require a special permit in Fairhaven.
ADU Rules
Dwelling conversions shall not be allowed unless the lot meets the minimum lot size in § 198-18 or 22,500 square feet, whichever is greater.
Units created through dwelling conversions shall not be less than 1,000 square feet, not including areas of the basement, attic or garage.
The applicant shall illustrate to the Planning Board that the requirements of the State Building Code are met.
Site requirements.
No expansion to the existing structure.
Parking shall be as provided for in § 198-27B(1).
No portion of the basement, attic or garage may be used for dwelling purposes.
Use of an existing on-site septic system to service proposed units shall be permitted only upon approval of the Board of Health.
Resources:
Millbury, MA
Millbury, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10 (10 is most accepting)
Last updated: 8.28.2024
What You Need To Know
Currently not in compliance with the Massachusetts Affordable Homes Act.
ADUs are allowed within all Residential and Suburban Districts on lots that meet the zoning district dimensional requirements or on lots/in structures that are legally pre-existing nonconforming.
Type of ADU Permit Required
ADUs require a special permit.
ADU Rules
Only one ADU is allowed on a lot.
The appearance of a single-family home must be kept in.
Any new entrance to the ADU must be either on the side or rear of the home.
The gross floor area of an ADU cannot be greater than 800 square feet.
Two off-street parking spaces must be provided for the residents of the ADU.
For ADUs built on lots with pre-existing nonconforming single-family homes, the living area of the existing single-family home cannot be increased in total square footage or footprint altered.
The Zoning Board of Appeals may allow in some circumstances deviations from certain requirements to accommodate individuals living needs.
Resources:
Middleborough, MA
Middleborough, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10
Last updated: 8.28.2024
Image source: Wikipedia
What You Need To Know
Middleborough, like all of Massachusetts since the passage of the 2024 Affordable Homes Act, allows ADUs by right. Each town has slightly different rules surrounding ADUs, but they all must adhere to the framework outlined by the state. The rules for Middleborough are outlined below.
Type of ADU Permit Required
ADUs in Middleborough do not require special permits, and can be built using a traditional building permit.
ADU Rules in Middleborough:
Middleborough allows one ADU per building lot.
An ADU can be a maximum of 900 square feet.
ADUs can be attached or detached from the main house.
Short-term rentals are prohibited.
Detached ADUs cannot be taller than 2 stories, or 25 feet - whichever is shorter.
ADUs must maintain the architectural style of the main house to the extent possible.
ADUs must have a separate entrance from the main house - attached ADUs can share an entry hall with the main house, but need a separate entry within the entry hall.
No multi-level exterior stairs are allowed as the main method of access to the ADU.
Detached ADUs cannot be built in the front yard.
Detached ADUs need to be built at least 10 feet from any other structure on the lot.
If the ADU is within 0.5 miles of a transit station, no additional parking is needed.
If it is further than 0.5 miles from a transit station, one off-street parking spot must be added.
If off-street parking is necessary, it must be in the side or back yard of the main house and use the existing driveway.
The water connection for the ADU must come from the main house.
ADUs must have a separate electric meter, located outside.
ADUs need a separate water shut off.
ADUs and the main house must remain in single ownership - a deed restriction recorded at the Registry of Deeds is required.
Propane is not allowed on a lot that has an existing gas connection (from MG&E) - we build all-electric homes, so this isn’t a problem!
Resources:
Duxbury, MA
Duxbury, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10 (10 is most accepting)
Last updated: 8.14.2024
Source: See Plymouth
What You Need To Know
Currently not in compliance with the Massachusetts Affordable Homes Act.
Duxbury allows ADUs only within existing single family homes.
Type of ADU Permit Required
ADUs are permitted under special permit in Duxbury. There are a number of hoops to jump through as the process is laid out in Duxbury’s zoning ordinance including approval from the Board of Appeals. If you’re interested in learning more about this process, please contact us.
ADU Rules
ADUs cannot be greater than 850 sq ft in area.
ADUs are only allowed within the existing dwelling and no alterations to the existing footprint can be made.
ADUs cannot be constructed on lots less than 20,000 square feet.
At least one additional parking space must be provided to serve the ADU.
The owner must reside in either the ADU or the primary dwelling.
The primary home must be at least 10 years old at the time of the special permit application, and the ADU must be built within a year of the date of the special permit application.
Resources:
https://www.town.duxbury.ma.us/zoning-board-appeals/pages/zoning-bylaws - Page 55-56
Marshfield, MA
Marshfield, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 4/10 (10 is most accepting)
Last updated: 8.14.2024
Image source: WATD News
What You Need To Know
Currently not in compliance with the Massachusetts Affordable Homes Act.
ADUs are allowed via special permit in the R-1, R-2, R-3, B-1, and B-2 districts through the Board of Appeals. If you’d like help determining what is possible on your property, please reach out to our team!
Type of ADU Permit Required
ADUs are permitted through the Board of Appeals via a special permit.
ADU Rules
ADUs are limited to 40% of the total living area of the single-family dwelling and limited to one bedroom.
Only one ADU is allowed per lot.
ADUs are only allowed within existing single family dwellings currently.
ADUs must be designed so that the appearance of a single family home is maintained.
There are lot size requirements for specific districts:
For properties in B-1 and R-3 the lot size minimum is 10,000 square feet.
For properties in B-2 and R-2 the lot size minimum is 20,000 square feet.
For properties in R-1 the lot size minimum is 40,000 square feet.
One additional parking space must be provided for the ADU.
The ADU and the existing single family home must remain in common ownership.
If the property is sold, a new special permit must be applied for.
Each year, the owner of the property must recertify that the home is their primary residence.
Resources:
Sandwich, MA
Sandwich draws a distinction between “Accessory Dwelling Units” and “Accessory Apartments” and provide different rules for each.
Sandwich, MA Accessory Dwelling Unit (ADU) Rules
Last updated: 11.17.2025
What You Need to Know
Sandwich, like all of Massachusetts since the passage of the 2024 Affordable Homes Act, allows ADUs by right. Each town has slightly different rules surrounding ADUs, but they all must adhere to the framework outlined by the state. The rules for Sandwich are outlined below.
Type of ADU Permit Required
ADUs in Sandwich do not require special permits, and can be built using a traditional building permit. Residents are allowed to build one ADU per single-family home.
ADU Rules
Accessory Dwelling Units (ADUs)
An ADU can be maximum 900 square feet, or half the Gross Floor Area of the main house; whichever is smaller.
ADUs can be attached, detached, or built within the main house.
ADUs must have a separate entrance from the main house.
Attached ADUs can share an entry hall with the main house, but need a separate entry within the entry hall.
Properties within ½ mile of a transit station do not require additional parking.
Properties outside of that area require one additional off-street parking spot.
Short-term rentals are not allowed. The minimum rental period for an ADU in Sandwich is twelve months.
The main house and ADU must be owned by the same person(s).
ADUs must have at least 1 dedicated parking space unless the ADU is within 0.5 miles from a transit station.
ADUs must remain in common ownership.
Resources: https://www.sandwichmass.org/DocumentCenter/View/10628/May-2025-Zoning-Bylaw (See pages 37-38)