Plymouth planners weigh sweeping state law changes that will force zoning rewrites

Joseph, the town planning director, told the Planning Board that the planning department has been monitoring a package of state law changes signed this month that will require Plymouth to change its zoning and some planning regulations.

The new laws include a requirement that multifamily housing be permitted in commercial zones that allow retail or office uses, a change that the town will need to address in the Highway Commercial district and possibly the Civic/Institutional district. Another law requires accessory dwelling units (ADUs) to be permitted “by right” in any zone that allows residential uses, and it allows conversions of existing nonconforming accessory structures into ADUs. A separate statute removes local authority to limit occupancy based on familial relationship and generally requires occupancy limits to be expressed as a per‑bedroom metric rather than by whether occupants are related.

Why it matters: the changes affect common local controls — whether multifamily requires special exception or is permitted, how Plymouth treats ADUs and conversions of commercial buildings to housing, how the town counts occupants in a unit and how many parking spaces the town may require for a new dwelling.

At the meeting, Joseph walked the…