ADU Rules in Carroll County, New Hampshire
1 towns covered · Reconciled with the 2025 state law · Last reviewed 2026-09-10
The short answer
Every town in Carroll County must allow one ADU — attached or detached —
by right on single-family lots.
That's the statewide floor under RSA 674:72, effective July 1, 2025. What differs town to town
is the details: size caps, parking, owner-occupancy, and how much of each town's posted ordinance
the state law now overrides. Pick your town below for the plain-English breakdown.
Carroll County towns
Not sure what your lot allows?
Get a free personalized ADU report for your property in Carroll County.
Get My Free ADU Report →Learn the statewide law
Wherever a town's rules are stricter than the state floor, the state law controls.
Read the full New Hampshire ADU law explainer →
Other counties
This guide is an independent informational resource, not legal advice; confirm
details with your town's planning department before you build.