Planning board moves to align ADU rules with 2024 state law, raise by‑right size to 1,000 sq ft

The Planning Board presented proposed zoning amendments to accessory‑dwelling‑unit (ADU) rules that would bring Concord into compliance with the 2024 state Zoning Act changes and expand by‑right unit size to 1,000 square feet.

The board said the revisions have seven goals: clarify that the Zoning Board of Appeals may grant special permits for ADUs on lots lacking required frontage only if the lot is a legal nonconforming lot; require that ADUs meet ordinary dimensional setbacks; remove an earlier requirement that an ADU be in an owner‑occupied structure that had been built and occupied for two years; and update the town code to use the statutory term "accessory dwelling unit." Most notably, the board proposes to allow ADUs by right up to 1,000 square feet (state law requires at least 900 by right). Planners said the extra 100 square feet avoids placing an additional administrative burden on owners and avoids repeated Town Meeting revisions for marginal square‑foot differences.

The board explained the change also harmonizes local and state law on transit proximity and other state requirements introduced in 2024. A resident, Sven Weaver, asked whether the bylaw could instead refer to the state minimum ("state minimum or 1,000 sq ft, whichever is larger"); planners agreed that language could be considered to avoid future patchwork changes if the state alters its minimum.

Why it matters: enlarging the by‑right ADU size and removing occupancy timing rules could make it easier for homeowners to add rental units for family or tenant housing, while the legal‑nonconforming clarification addresses how ADUs may be approved on small legacy lots.

Ending: The board will finalize warrant language and consider whether to reference the state minimum or retain the local 1,000‑sq‑ft limit.