Westborough planning staff review state ADU changes, housing production plan and proposed zoning updates

Town planning staff briefed the select board and planning board on recent state housing law changes and local proposals aimed at increasing housing options, clarifying regulatory impacts and preparing zoning changes for the town's October/March schedules.

Jenny Gingras, Westborough's director of planning, summarized the state Affordable Homes Act (signed Aug. 6) and described how its ADU provisions will affect local zoning. Under the state changes explained at the meeting, accessory dwelling units (ADUs) will be an as-of-right use in single-family residential districts if they meet the new definition; the law allows ADUs up to 900 square feet (attached or detached) and specifies gross floor area as the measurement. Municipalities cannot impose owner-occupancy requirements; reasonable dimensional regulations (setbacks, height, site plan review) remain allowed, and short-term rental restrictions may also be imposed locally. Gingras said those ADU provisions take effect Feb. 2 and that the town plans to prepare bylaw amendments for the March town meeting and to hold public information sessions in advance.

Gingras and Fred Leonardo, the town's community development director, advised the boards that some local ADU requirements (for example, Westborough's owner-occupancy and attachment rules and a maximum tied to primary dwelling size) will not be compliant and therefore require revision. Leonardo recommended retaining a special-permit pathway for oversized ADUs (for example, ADUs larger than the state's 900-square-foot threshold) because the town's existing special-permit procedure offers more flexibility than variance processes.

The meeting also included a presentation by Luke Mitchell of VHB on the town's housing production plan. Mitchell outlined demographic trends, local housing inventory characteristics and infrastructure constraints (sewer capacity) and recommended five goals: identify underutilized parcels (downtown, corridors, transit-adjacent sites), update zoning to better enable housing types the town needs, leverage state funding and partnerships, align housing with regional economic development needs, and ensure infrastructure supports new housing projects. Mitchell's slides showed cost-burden statistics (about 19% of owner households and nearly 40% of renter households pay more than 30% of income for housing in Westborough) and emphasized shortages of smaller starter homes.

Following the plan, Gingras presented two zoning-related articles staff will bring forward: a consolidated inclusionary zoning bylaw and revisions to the Highway Business district along Route 9. The inclusionary bylaw would combine existing affordability requirements into a single section, add a 10-unit minimum project threshold to trigger affordability requirements, broaden affordability tiers (proposed range up to 110% AMI for certain units), require a local preference order (current residents, employees, town employees, veterans), set an ADA-accessible share for affordable units (25% of the affordable units), and allow payments in lieu only when the planning board finds an unusual net benefit and after considering the affordable housing trust balance. Gingras said the bylaw seeks to maintain or increase the town's share of units on the subsidized housing inventory (SHI) and that a public hearing on the article is scheduled for Sept. 17.

The Highway Business district amendment would replace the current section and expand special-permit flexibility for multiple uses, reduce the maximum on-site open-space requirement in exchange for public benefits (a point-based system with a minimum retained on-site open space of 30%), and create a green-revenue account to accept payments for off-site benefits (the select board would administer regulations for that account under MGL c.44, x53k). Sustainable-design elements eligible for points include LEED certification, HERS rating targets, EV charging (installed Level 2/3 chargers above code minima), green roofs, stormwater recharge measures, and donations of usable open space to the town or qualified non-profits. Gingras said planning staff and a zoning working group developed the draft in consultation with developers and sustainability staff, and that regulations would refine point values and eligible options.

Board members raised technical questions about achievable AMI splits, the legal implications of the merger doctrine changes in the state law for historic lot lines, whether certain historically merged downtown lots might become buildable, potential overlaps between existing stormwater requirements and proposed sustainability credit items, and how the planning board would evaluate off-site land donations.

Next steps recorded in the meeting: staff will prepare draft zoning amendments, seek developer and Affordable Housing Trust input, hold public hearings (including Sept. 17 for the inclusionary bylaw), and bring proposed bylaw language to town meeting as required. Gingras reiterated the need to post ADU bylaw language and hold a planning board hearing before Feb. 2 to ensure retroactive effect if town meeting approves amendments.