Cohasset Considers Floor Area Ratio to Curb 'Mansionization'

Planning board proposes shift from lot coverage to 3D measurement, aiming to maintain neighborhood character and limit oversized homes

COHASSET, MA - September 27 - Cohasset's Planning Board is proposing a significant change in how the town regulates house sizes, shifting from a two-dimensional lot coverage measurement to a three-dimensional floor area ratio (FAR) system. The proposal aims to address concerns about “mansionization” and maintain neighborhood character.

Planning Board Chair Tom Callahan presented the proposed bylaw amendment to the Select Board on Friday the 27th, explaining that the current 20% lot coverage limit could potentially allow for excessively large houses on certain properties.

"We are seeing an increasing trend on the planning board with our large home reviews, very large houses," Callahan said. "The one that's being built off North Main Street and Little Harbor, right on Little Harbor, is over 10,000 square feet, but they happen to have a very, very big lot."

The proposed FAR system would set limits based on the total floor area of a house relative to its lot size, rather than just the footprint. The suggested ratios are 0.17 for Residence A districts, 0.12 for Residence B, and 0.09 for Residence C.

Callahan emphasized that these numbers are based on averages of current development patterns in town. "We're trying to incorporate what we've done to date and not let things get way out of hand," he said.

Some Select Board members expressed concerns about the potential impact on homeowners. Board member Chris Plecs worried that many existing homes might not qualify under the new system.

"I looked at a couple of houses in my neighborhood and was surprised to see that a lot of houses that to me are consistent with the neighborhood, reasonably sized, wouldn't qualify under what had been proposed a year ago," Plecs said.

Callahan acknowledged the concern and stated he was open to adjusting the numbers. The proposal includes a provision allowing up to a 10% increase in FAR through a special permit process.

The Select Board voted 3-1 to refer the proposal to the planning board for further review and a public hearing. Plecs voted against the referral, citing the need for more specific examples of how the change would affect existing homes.

In a related matter, the board also discussed updates to the town's accessory dwelling unit (ADU) regulations to comply with new state laws.

The proposed changes would allow ADUs up to 900 square feet by right and potentially permit larger units up to 1,250 square feet through special permits. This update aims to bring Cohasset into compliance with recent state legislation promoting ADUs as a means of increasing housing options.

"We had to tweak what we just did last fall to conform with the new state law," Callahan explained. "Supposedly, we have to have all these things in place by February, and that's right between our two town meetings, so we figured we'd just get it done now."

Select Board member David Farrag raised concerns about potential impacts on rental regulations and public safety. "We're going to have to see as the regulations come on this, how they're going to merge with that because somebody could make an ADU, but then maybe they're renting it out for other purposes," Farrag said.

The board unanimously voted to refer the ADU amendments to the planning board for review.

Both proposals will be subject to public hearings before the planning board in the coming weeks. The planning board will then make recommendations to the Select Board, which will decide whether to place the amendments on the town meeting warrant.

Callahan emphasized the importance of public input in shaping these proposals. "I'm going to have a public forum next Monday. And I'm hoping the public will give some feedback because that'll certainly push us in a direction one way or the other," he said.

*editors note: the Select Board opted not to move forward with this proposal at this time following the public hearing on 9/30 and subsequent meeting on 10/1