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)