Planning board continues hearings on ADU bylaw, school addition and multiple site plans; raises safety questions about proposed Valvoline driveway

The Southborough planning board on Monday, March 24 continued public hearings on two warrant articles to implement state ADU requirements and on several major and minor site-plan matters, and directed staff to seek additional technical reviews and safety data on a proposed quick-lube at 361 Turnpike Road.

Planning board members said they want more clarity from town staff, the building commissioner and peer reviewers before final action on several matters — and publicly flagged safety concerns about a proposed driveway/egress for a Valvoline “instant oil change” site that would use Flag Road rather than Route 9.

Accessory dwelling units (ADUs). The board heard a presentation on Articles 28 and 29 of the annual town meeting warrant, which would amend the zoning bylaw to implement the state Affordable Homes Act (Act of 2024) changes that allow ADUs up to 900 square feet by right and streamline a special-permit path for larger ADUs. Under the draft zoning, the town would (1) rename “accessory apartment” to “accessory dwelling unit,” (2) allow an ADU of up to 900 square feet by right (through an abbreviated site plan), (3) allow one ADU per single-family property, (4) prohibit short-term rentals under 31 days in ADUs, (5) remove the town’s existing cap on the number of ADUs, and (6) move ADU special-permit decisions to the planning board (currently the ZBA handles them). The presenter noted the changes are intended to conform local code to the state law and to provide clarity for applicants and staff.

Board members pressed staff about the new concept of an “abbreviated site plan” (currently not defined in the town code) and about feedback from the building commissioner, who had suggested some ADUs could be handled only with building permits. The planning board asked staff to prepare a Q&A and a plain-language handout for town meeting, and to confirm alignment with the building commissioner and ZBA. The public hearing was continued to April 7, 2025 at 5:30 p.m.

Fay School, 48 Main Street…