The Historic District Commission discussed a proposed zoning bylaw amendment, Article 4181L, that would change how lots with preexisting structures are treated when owners pursue subdivision.

Under current practice, multiple structures that predate the island's subdivision controls (adopted in 1955) can trigger a by-right subdivision that often carries retroactive allowances for increased ground cover or volume. Planning board representative Emily Molding told the commission that the planning board supports the article and that she had briefed the commission on technical edits recommended by town counsel.

The amendment would preserve the state law right to subdivide but require a special permit from the Zoning Board of Appeals (ZBA) for any increase in ground cover or building volume tied to a subdivision of a lot with preexisting structures. It also would prohibit an owner from obtaining more development than the original single lot would have allowed and would place deed restrictions on both resulting lots so any special-permit conditions remain enforceable.

Commission members said the change aims to prevent out-of-scale infill—“we get really weird big buildings on this much space in awkward locations, landlocked,” one member said—by closing a loophole that has let subdividers achieve higher density through the 4181L path. The amendment also adds notice and hearing safeguards: unlike by-right subdivision, the special-permit route would trigger public notice and an opportunity for public comment.

Participants noted the planning board reviewed the article as the statutory board that vets zoning articles for Town Meeting. The commission discussed which body would be the permit-granting authority under the draft language; the current draft names the Zoning Board of Appeals as the special-permit grantor. Planning staff present confirmed that the ZBA cannot grant collective ground-cover relief beyond the ZBA’s statutory limits (the discussion cited a 40% collective cap in existing zoning language), which the amendment’s drafters said is intended to avoid a route to net increases in density.

Commissioners and attendees also discussed nonregulatory options to reduce demolition and loss of contributing historic structures, such as voluntary deed restrictions, tax or preservation incentives, and Certified Local Government (CLG) coordination between the commission and the town's preservation planner. The planning board representative and commission members said further work on implementation details will occur before Town Meeting; the planning board intends to hold its public hearing on related zoning articles in the coming days.

No formal vote or motion on Article 4181L was recorded at the commission’s workshop.