Southborough Affordable Housing Trust coalesces around 10–12.5% goal for proposed 55+ inclusionary bylaw

The Town of Southborough Affordable Housing Trust spent the bulk of its meeting on a draft 55-plus inclusionary zoning bylaw, debating how large a share of new senior housing should be set aside as affordable and how to handle buyouts and density rules.

Speaker 2, who summarized the town’s current inclusionary rules and neighboring town comparisons, said Westborough recently adopted a 15% requirement for new developments of 10 or more units, with units affordable at up to 80% of area median income (AMI) and an additional 5% at up to 120% AMI. "So they did an economic feasibility analysis to come to those numbers," Speaker 2 said, adding that the Westborough approach could provide useful data for Southborough.

Members debated whether the new 55-plus bylaw should require 10% affordable units — the floor in state MBTA Communities guidance — or align with other Southborough bylaws at 12.5%. "I definitely think at least 10% makes a lot of sense," Speaker 1 said, adding that going substantially higher could make private development uneconomic. "Once you start getting higher, it's just going to kill the project," Speaker 1 said.

Trust members favored flexibility on income tiers. The group discussed options including a base target at 80% AMI and a structure allowing some units closer to 120% AMI to create an average AMI target across units. Speaker 1 noted that an "average of 80" could give the planning board and developers leeway to mix deeper- and shallower-affordability units. Speaker 1 also referenced comments by a local stakeholder urging deeper affordability at 50–60% AMI.

Buyouts and payment-in-lieu were a significant point of discussion. Speaker 3 asked whether the buyout provision in the draft was a way to "get around these percentages." Speaker 2 confirmed that developers can seek a special permit to build off-site or make a cash contribution, and that Southborough’s current major-residential bylaw directs such funds to a municipal program (noted as SHOPC in the current language), which the Trust said will need updating.

Trust members discussed possible buyout formulas. Speaker 2 described Westborough’s method of calculating a payment using a multiple of a 4-person AMI, noting Southborough’s 4-person AMI figure of $173,000 and estimating an equivalent buyout of roughly $350,000 per unit under that approach. "At that value, probably... I would just build it on-site," Speaker 1 said, explaining that a high buyout amount could incentivize on-site construction rather than cash payments.

Density and site eligibility drew sustained comment. Members said an earlier draft’s cap of 3 units per contiguous acre (exclusive of 80% wetlands) was "very low" for the proposed 55-plus typology; the Trust signaled it would ask the planning board to consider higher density allowances in appropriate districts (for example, Route 9 or the downtown overlay) and to consider special-permit pathways so denser projects remain discretionary.

The Trust agreed to relay its discussion to the planning board, with Speaker 2 planning to follow up with planning staff and to present the Trust’s preferences for percentage, AMI targeting, buyout mechanics, and density. Speaker 1 said the Trust wants the bylaw on next year’s town meeting warrant and urged timely coordination with the planning board so language can be finalized before town meeting.

What’s next: Trust members will continue drafting the bylaw language, share follow-up notes with the planning board, and consider whether the bylaw should specify that any buyout payments be directed to the Affordable Housing Trust rather than another municipal account. The Trust also discussed participating jointly in a planning board meeting to walk through the proposal.