Burlington, MA
Burlington, MA Accessory Dwelling Unit (ADU) Rules
City Acceptance Rating: 5/10
Last updated: 10.29.2024
Image source: HDPT Physical Therapy
What You Need To Know
Currently not in compliance with the Massachusetts Affordable Homes Act.
A single accessory apartment is permitted within a one-family dwelling. The ADU size cannot exceed 30% of the net floor area of the primary dwelling and must maintain a single family appearance with a minimum of 4 parking spaces.
Type of ADU Permit Required
ADUs only require a building permit, but are limited to single family residence districts only.
ADU Rules
Owner Occupancy Requirement: The property owner must live in one of the units, with temporary absences allowed for up to six months.
Unit Limitations: Only one accessory apartment is allowed within a single-family dwelling.
No Lodgers Allowed: Neither the primary nor accessory unit can have boarders or lodgers.
Minimum Dwelling Size: The dwelling’s gross floor area, including the basement, must have been at least 1,800 square feet as of January 1, 1989, verified by the Building Inspector’s records.
Maximum Accessory Unit Size: The accessory apartment cannot exceed 30% of the net floor area of the primary dwelling (as of January 1, 1989).
Bedroom Limit: The accessory apartment can have a maximum of two bedrooms.
Exterior Appearance: The structure must retain the look of a single-family dwelling:
Stairways to upper stories must be enclosed within the dwelling’s exterior walls.
Enlargements are restricted to minimal additions needed to meet building, safety, or health codes or to enclose entryways or stairways.
New entrances must be on the side or rear of the dwelling.
If modifying multiple front entrances, ensure one appears as the main entrance and the others as secondary.
Parking: At least two off-street parking spaces must be provided for both the primary and accessory units.
Resources:
https://www.burlington.org/ArchiveCenter/ViewFile/Item/570 PDF page 97