Atkinson's ADU ordinance (§460) already cites RSA 674:71-73 directly and tracks the 2025 state law closely — including a generous 1,000 sq ft size…
Read the full Atkinson ADU guide →Auburn's 2026 Zoning Ordinance rewrote its ADU rules to closely track the new state law — replacing a 2024-era 'attached only, by special exception,…
Read the full Auburn ADU guide →Brentwood already allows detached ADUs by right and same-time construction with the main house — but where its size formula (the LESSER of 1,100 sq…
Read the full Brentwood ADU guide →Candia's zoning ordinance — reaffirmed as recently as March 10, 2026, well over a year after the state's July 1, 2025 ADU law took effect — still…
Read the full Candia ADU guide →Yes — Chester allows one ADU (verified with the town), up to 1,000 sq ft.
Read the full Chester ADU guide →State law now guarantees Deerfield homeowners a parking-location choice, a detached ADU without extra acreage, and the right to convert an existing…
Read the full Deerfield ADU guide →Derry rewrote its ADU ordinance effective December 19, 2025 to largely match the new state law — including finally allowing detached-garage…
Read the full Derry ADU guide →State law guarantees at least one ADU by right in Exeter, and town staff described ADUs as by-right as of mid-2024 — but the town's current ordinance…
Read the full Exeter ADU guide →State law guarantees you one ADU by right, and Hampstead's ADU guidelines — dated to match the July 1, 2025 state law — largely deliver: one ADU,…
Read the full Hampstead ADU guide →Under the state's July 2025 by-right ADU law, Hampton's 2024-dated ordinance is overridden on its biggest hurdles: the CUP hearing requirement, the…
Read the full Hampton ADU guide →Kensington rewrote its ADU ordinance effective March 6, 2026 to match the state's by-right law: a straight building permit (no more…
Read the full Kensington ADU guide →State law (RSA 674:71-73, effective July 2025) guarantees one ADU by right — and Londonderry already permits that — but the town's ordinance, last…
Read the full Londonderry ADU guide →North Hampton actually did the work — voters passed a full ADU rewrite on March 10, 2026 to match the new state law, and it even skips the extra…
Read the full North Hampton ADU guide →The July 2025 state law guarantees one ADU by right — Northwood already delivers that, detached units included — but its ADU rules (last updated…
Read the full Northwood ADU guide →Plaistow rewrote its entire ADU article at the March 10, 2026 town meeting (Article Z-26-8) specifically to comply with the new state law — and in…
Read the full Plaistow ADU guide →State law (RSA 674:71-73, amended by HB 577 effective July 1, 2025) now entitles you to one by-right ADU; Portsmouth's ordinance — as amended through…
Read the full Portsmouth ADU guide →Raymond amended its ADU ordinance in March 2026 to track the new state law — but it kept a 500 sq ft minimum size, a mandatory connecting door, an…
Read the full Raymond ADU guide →Salem rewrote its ADU rules on August 29, 2025 to comply with the new state law — most notably reversing an outright ban on detached ADUs — but the…
Read the full Salem ADU guide →Sandown scrapped its old special-exception ADU process entirely and replaced it with a by-right ordinance that closely tracks the 2025 state law —…
Read the full Sandown ADU guide →Stratham's ADU rules (Zoning §5.4, last revised March 2022) predate the July 1, 2025 state law: the town's own text requires 4 total parking spaces…
Read the full Stratham ADU guide →Windham voters overhauled the ADU ordinance on March 10, 2026 — and while the town got the big things right (detached ADUs now allowed, 950 sq ft,…
Read the full Windham ADU guide →Get a free personalized ADU report for your property in Rockingham 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 →