Above: When the Town sought approval for its ADU bylaw, voters were shown a variety of styles that would be allowed (see top row). Now, voters will consider allowing smaller homes to take better advantage (see bottom row). (images edited from past presentation)
Last fall, voters approved zoning bylaw rewrites to reflect the changes in state laws allowing homeowners to add an “Accessory Dwelling Unit” by right with size restrictions. Before the vote a member of the Zoning Board of Appeals and the Planning Board discussed potentially returning to voters with a version that increases the ability for owners of smaller homes to add ADUs.
Since then, the two boards worked on a more permissive version, which voters will be asked to adopt at Annual Town Meeting this Saturday.
The current ADU bylaw allows adding one residential unit that is the lesser of 900 sq ft or ½ the gross floor area of the primary residence. Under the pre-existing bylaws, homeowners can also pursue a special permit for an Accessory Apartment. But that use is capped at 25% of the primary building’s gross floor area.
Article 29 proposes changing the bylaws to double the allowed size for some homes and increase the by right cap by at least ⅓ overall. An ADU would now be allowed up to 1,200 sq feet, capped at the gross floor area of the primary residence.
(For those unfamiliar, the gross floor area is the interior square footage of all the floors of the buildings, excluding “stair and elevator wells, garages, basement and other areas used only for storage or for services incidental to the operation and maintenance of such a building or buildings”.)
The change would remove special permits all together, except for under Adaptive reuse of historic buildings.
For most homes, the permits would no longer be needed. But it would remove the current potential for a special permit to add an ADU that is over 1,200 sq ft at a large residence with a gross floor area over 4,800 sq ft.
Background
After the state passed a law that largely protects the limited by-right use of small ADUs in residential zones, the Planning Board worked on revising the Town’s zoning bylaws to comply. At Annual Town Meeting in 2025, the board a version of the ADU bylaw with state allowed local “protections” including Site Plan Review. After some commenters objected to restrictions, the board failed to get the 2/3 approval needed to pass the bylaw change.
Based on that outcome, the board brought a simplified version to the Special Town Meeting last fall. It updated the zoning codes to be consistent with the state requirements. (The only other change was to disallow the use of mobile homes as ADUs, which the board believed the state law allowed. That change was later struck by the Attorney General’s Office.) The zoning rewrite also removed the residential use from the Industrial Park zone.
At the fall Town Meeting ZBA member Michael Robbins raised his concern that the smaller cap of ½ the gross floor area is unfair to owners of smaller home.
Robbins suggested those owners are also the ones more likely to need ADUs for financial reasons. Planning Vice Chair Marnie Hoolahan responded that the Planning Board would be happy to consider a change. But she suggested that it should go through a public hearing process first.
Robbins didn’t object to that approach, and chose not to make a motion to amend the Article. The article passed as written. (Just this week, the Town Code was updated to reflect the new language as approved by the Attorney General’s office in February.)
This winter, the ZBA worked on the revised version and discussed it with the Planning Board. Both boards agreed that it made sense to raise the allowed size and proportion of the by right use. And they agreed that a Special Permit version wasn’t necessary.
Specific Changes Outlined in the Zoning Article
Article 29 includes a lot of language about striking several sections and (renumbering some where needed). I compared to the existing bylaws to confirm that the changes simply mean the following changes. . .
Under Residential zoning, it strikes the text:
Accessory dwelling unit that is not larger in gross floor area than ½ the gross floor area of the principal dwelling or 900 sq. ft., whichever is smaller.
That is replaced with:
Accessory dwelling unit that is not larger in gross floor area than 1200 sq ft. provided that the Accessory Dwelling Unit does not exceed the gross floor area of the principal dwelling. Only one Accessory Dwelling Unit may be established on a lot.
Under the bylaws for each zone that currently includes Special Permit use for ADUs “whose gross floor area is greater than 900 sq. ft.”, the use is removed. Each of those zones already include under permitted uses, “All uses permitted in the residential districts”. Those changes are applied to the following zones: Business Village District, Highway Business District, ID (Industrial District), SP (Research, Scientific and Professional District), and Downtown District.
The section of the bylaws that currently outlines the Special Permit requirements for ADUs (174-9 B) is struck in its entirety.
The section of the bylaws outlining Adaptive reuse of historic buildings (174-IJ.8) strikes the following condition under ADUs:
The habitable floor area of the accessory dwelling unit shall not exceed 35% of the habitable floor area of the entire dwelling, plus that of any accessory building used for the accessory dwelling unit.
The zoning bylaw changes will be voted on at this Saturday’s Annual Town Meeting at Trottier Middle School. The meeting opens at 10:00 am. For the full meeting Warrant, click here. For more Town Meeting coverage, click here.
