Amherst's accessory-apartment ordinance (Zoning §3.5) hasn't been amended since 2016-2019 and hasn't been reconciled to the state's July 2025 ADU law…
Read the full Amherst ADU guide →Yes — Antrim allows 2 by-right ADUs (verified with the town), up to 1,500 sq ft.
Read the full Antrim ADU guide →Brookline's ADU ordinance predates the state's July 2025 law and was never updated to match it — the special-exception/ZBA hearing requirement, the…
Read the full Brookline ADU guide →State law now guarantees one ADU — attached or detached — by right, and while Hollis revised its zoning ordinance in April 2026, Chapter IX.K still…
Read the full Hollis ADU guide →The July 2025 state law overrides Hudson's badly outdated ADU ordinance (last amended in 2019) on four major points: the ordinance still bans…
Read the full Hudson ADU guide →The July 2025 state law overrides several of Litchfield's ADU rules, which haven't been touched since March 2021: the Planning Board hearing for a…
Read the full Litchfield ADU guide →Manchester rewrote its entire zoning ordinance effective March 1, 2026, and its new ADU rules are unusually well-aligned with the July 2025 state law…
Read the full Manchester ADU guide →New Hampshire's 2025 ADU law (HB 577) now guarantees one ADU — attached or detached — by right; Merrimack's ordinance, last revised October 2016,…
Read the full Merrimack ADU guide →State law (RSA 674:71-73, effective July 2025) guarantees one ADU by right — Mont Vernon already permits that administratively — but its ordinance,…
Read the full Mont Vernon ADU guide →Nashua's ADU ordinance is one of the most recently updated in the state (Dec. 23, 2025) and is largely aligned with HB 577 — but a few gray areas…
Read the full Nashua ADU guide →Pelham's ADU ordinance was last substantively amended in March 2022 — before the July 2025 state law overhaul — and its CUP-for-every-ADU process,…
Read the full Pelham ADU guide →Weare's ADU rule (Zoning §19.1.10, last amended March 2017) still requires a Zoning Board special exception, bans detached ADUs outright, demands two…
Read the full Weare ADU guide →Windsor's zoning hasn't been touched since March 2021 — four years before the state's ADU law changed — so its special-exception process and…
Read the full Windsor ADU guide →Get a free personalized ADU report for your property in Hillsborough County.
Get My Free ADU Report →Wherever a town's rules are stricter than the state floor, the state law controls. Read the full New Hampshire ADU law explainer →