Tiverton planning board debates new ADU, accessory-structure limits as state law narrows local control

The Tiverton Planning Board on Sept. 25 spent more than an hour debating how to translate recently changed state rules on accessory dwelling units (ADUs) and adaptive reuse into local ordinance language and whether the town can use zoning to limit impacts.

Board Chair Bill Gerlach opened the workshop by emphasizing this was an editing session rather than a hearing or vote. Todd Romano, land-use counsel, told members, “This is a workshop, so you’re not even required to take any votes,” and said staff would revise the draft and return it as a package for a formal vote later.

Why it matters: the state has recently required municipalities to allow ADUs in specific circumstances and tightened adaptive-reuse eligibility. Board members said they want rules that protect neighborhood character while complying with state law. Several members and town counsel flagged where state language preempts municipal discretion and where local rules can still be applied.

Major points discussed

State preemption and local options: Board members and counsel repeatedly noted that the new state ADU provisions limit local authority. Romano and interim planner Ashley Sweet explained the state law allows ADUs in three scenarios, including as a reasonable accommodation for a family member with a disability, and that the statute prevents municipalities from revoking an ADU when the qualifying circumstance ends: “the law actually says that you can’t revoke the ADU for a change [in] occupancy,” Romano said. Counsel and staff told members the town has “practically zero ability” to undo or narrowly restrict some state-mandated ADU entitlements.

Owner-occupancy and eligibility: The draft includes an owner-occupancy requirement only for one eligibility pathway. Board members debated whether the town can legally add owner-occupancy to other pathways; Romano said that may be “a bridge too far” legally but he will research whether additional owner-occupancy limits can be defended.

One ADU-per-lot rule, septic/water limits: The board reviewed state language that allows an ADU in a primary dwelling or detached accessory structure but caps one ADU per lot. Members asked how water and wastewater capacity will be enforced; staff and counsel said approval of an OWTS or water tie-in by the relevant state or district agency (for example DEM or the wastewater district) is required and is the practical limiting mechanism: if an applicant cannot obtain septic approval the town cannot issue a building permit.

Size, occupancy and transient use: The draft ties ADU unit sizes to state minimums (examples discussed: one-bedroom maximums commonly treated as 900 square feet or 60% of the principal dwelling, and two-bedroom 1,200 square feet or 60%, whichever is less). The board also confirmed ADUs cannot be used for short-term tourist occupancy (generally defined in the draft as under 30 days).

Accessory structures and setback threshold: Board members focused on accessory buildings (sheds, garages, barns) because state law links dimensional treatment of accessory structures and ADUs. The working proposal on the table combined two elements: a proximity threshold and an absolute cap. For rear/side-yard proximity, the board agreed that accessory structures smaller than a small threshold should be exempt from stricter district dimensional standards; the board settled on 120 square feet as the size below which a structure may remain at the current 5-foot rear/side setback. For larger accessory buildings they proposed requiring the structure to meet the principal-structure dimensional standards for the zoning district.

Maximum accessory footprint tied to ADU rules: Because the state ties ADU and accessory-structure regulation together, the board sought a number that preserves the town’s rural character without forcing the town to permit ADUs as large as some accessory buildings. The board debated multiple figures and agreed on a working maximum of 480 square feet for detached accessory structures, or 60% of the principal structure, whichever is less, with pathways for applicants to seek relief (administrative modification up to 25% or a variance to the zoning board).

Fencing and screening heights: The board reached a working consensus on residential fence heights in yards: a 4-foot maximum within the front yard setback and a 6-foot maximum elsewhere (side and rear yards) while preserving the town’s sight-line and safety standards near streets and intersections.

Enforcement and practical limits: Members raised enforcement concerns — especially verifying owner-occupancy, whether ADU permits granted for disability accommodations could be misused, and how to police transient or short-term rental use. Counsel and staff warned that some verification options are tightly constrained by privacy and federal/state law; Romano noted the town’s enforcement tools are mostly limited to building-permit and septic/water approvals, which are required at the permitting stage.

What the board directed staff to do

- Staff (Ashley Sweet and Todd Romano) were instructed to revise the draft to reflect the board’s agreed numeric thresholds (120 sq ft proximity threshold; 480 sq ft accessory cap or 60% of primary structure, whichever is less; and fence-height standards) and to return the full package for formal consideration and eventual transmittal to the Town Council. - Counsel was asked to research whether the town can add owner-occupancy requirements to additional ADU eligibility paths and whether schools, religious facilities or other building types can be added to the adaptive-reuse vacancy requirement.

Ending: The proposal remains a draft. Board members repeatedly emphasized the limits placed by new state law and the need to explain the local rationale clearly when the package goes to the council. Staff will produce a revised, annotated packet for the board’s next formal review before any vote or public hearing.

Quotes from the meeting

"This is a workshop, so you're not even required to take any votes," Todd Romano said during the session, describing the meeting's procedural role.

"The law actually says that you can't revoke the ADU for a change [in] occupancy," Romano told the board when discussing state protections for ADU permits.

Ending note: The planning board did not vote on any ordinance changes at the workshop; members agreed edits tonight would be incorporated and returned for the formal vote and public hearing process.