Affordable Housing Trust backs 12.5% affordable-unit target for proposed 55+ zoning change

The Town of Southborough Affordable Housing Trust voted to go on record supporting a 12.5% affordable-unit requirement in a proposed 55-plus housing zoning article ahead of planning-board public hearings.

Committee members described why the change is being proposed: the town has reached the bylaw’s existing cap (reported as 7% of units) and the Trust wants to allow more senior housing that includes an affordable component. A planning-board draft prepared by Marnie Houlihan and others includes a density assumption (6 units per acre) and a revised formula for fractional-unit payments that would require at least one affordable unit on many projects and use payments only for fractional obligations.

A committee member outlined how the proposed calculation would work: "So if you're building 4 units, you have to have 1 affordable," and said under certain density assumptions the fractional formula can change the effective percentage. Several members urged clarity in the payment-in-lieu language, warning that confusing ballot or bylaw text can derail passage at town meeting.

Supporters said 12.5% aligns with other recent local zoning (the downtown mixed-use district and recent major residential developments) and sits within a regional range of 10%–15% commonly used in nearby towns. Others cautioned that higher thresholds in denser urban areas (20% in Cambridge or Somerville) have at times reduced private development activity, and that the committee should be wary of imposing a level that would make projects infeasible.

By motion, the Trust voted to support the 12.5% figure as its formal position to share with the planning board; the committee also asked that planning clarify the fractional payment language and prepare the required two public hearings for the zoning articles. The Trust plans to have at least one member attend planning-board hearings and will prepare materials for the upcoming Select Board update.

The planning board will sponsor the zoning article and schedule public hearings as required; the Trust’s role is advisory in this stage. The committee’s action was a statement of position rather than a final zoning change — the planning board and town meeting retain formal authority on the bylaw.