| Max size | 750 sq ftattached or detached |
|---|---|
| Min size | No town minimumbuild as small as code allows |
| Bedrooms | Up to 2 |
| Type | Attached or detacheddetached gated on full lot minimum |
| Parking | Required"adequate off-street"; count unstated |
| Owner-occupancy | Requiredin either the ADU or the primary home |
| Short-term rental | Not stated |
| Utility connection | Tie into the existing electrical connection or choose a separate metersame statewide |
The July 2025 state law (RSA 674:71–73) overrides local ordinance language that conflicts with it — even language a town still has posted. Here's what that means in Strafford:
Since July 1, 2025, state law entitles you to a simple administrative building permit for one ADU — no board hearing, no notice-to-neighbors process, no discretionary vote. Strafford's ordinance still routes every ADU application through a Zoning Board of Adjustment special-exception hearing with fees and abutter notification, but state law now overrides that process.
State law says that if your lot is large enough for your existing single-family home, you're entitled to add one detached ADU. Strafford's ordinance still tells smaller-lot homeowners they can't have a detached ADU unless their lot alone is big enough to support a whole separate house (2+ acres) — an acreage gate state law no longer allows.
If Strafford's Building Inspector applies the 'additional family unit under a common roof' lot-area add-on to ADUs, that's an acreage penalty the state no longer allows. Whether the town actually enforces this against ADUs (vs. only true two-family homes) is unconfirmed — ask the Building Inspector directly — but the ordinance text as written supports the town doing so, which would be superseded by state law.
State law gives the homeowner the choice of a shared or fully independent entrance. Strafford still mandates a connecting interior door for every attached ADU — the town cannot require the interior connection.
Strafford's 'adequate off-street parking' language doesn't say how many spaces or whether it must be on your own lot. It isn't clearly worse than the state floor, but it also doesn't confirm your off-site option — worth clarifying directly with the Building Inspector before assuming you must park on-site.
State law says you can convert an existing detached structure — like an old garage that sits closer to your property line than today's 25-foot setback allows — into an ADU despite the nonconformity. Strafford's ordinance as written doesn't say you can, but the state-law exemption applies regardless of what the town's page says.
This clause is common and often defensible, but whether Strafford applies the exact same 'aesthetic continuity' standard to ordinary new single-family homes (and not something stricter, just for ADUs) is unconfirmed. An attorney call.
The controlling rule first: since July 1, 2025, RSA 674:71-73 (as amended by HB 577) guarantees one ADU by right — attached or detached — wherever single-family homes are allowed, with no special-exception hearing, a size cap no lower than 750 sq ft, and at most one required additional parking space (owner's choice of on-site or off-site). Strafford's ADU ordinance (Zoning §1.4.1.K, 'Accessory Dwelling Unit (ADU) Ordinance') was adopted effective March 14, 2017 and has not been amended since, meaning it predates the state law by more than eight years and was never updated to match it. As written, Strafford requires every ADU applicant to go through a Zoning Board of Adjustment special-exception hearing with site plan and building plan review — but state law now overrides that: you're entitled to a by-right administrative permit. A detached ADU is allowed in principle, but the town's text says only if the lot independently meets the full district minimum lot size (2 acres, or 5 acres above 800 ft elevation) — an acreage gate state law no longer permits. The town also mandates a connecting interior door for attached units (removing the homeowner's state-guaranteed choice of a separate entrance), pulls in general dimensional rules that may add a 20,000-sq-ft lot-area penalty for the 'additional family unit,' offers no exemption for converting an existing nonconforming detached structure like an old garage (an exemption state law now requires), and states an 'adequate off-street parking' requirement without confirming the homeowner's right to choose an off-site space. On the size side, Strafford's ordinance caps ADUs at 750 sq ft and allows up to 2 bedrooms — both within what the new state law still permits a town to impose (750 sq ft is the smallest maximum a town may set), so this part of the ordinance doesn't need to change. Bottom line: whatever Strafford's own zoning page or a town official tells you about needing a special exception, board hearing, or acreage minimum for a detached ADU, the town's ordinance still says those things — but state law now overrides most of them. See the conflicts list for full citations, and check the current state-law floor before accepting any of the older restrictions.
Get a free personalized report for your address in Strafford — including where the 2025 law works in your favor.
Get My Free Strafford ADU Report →House Bill 577 (2025) amended RSA 674:72, effective July 1, 2025. Wherever Strafford's ordinance is stricter than this floor, the state law controls. Read the full NH ADU law explainer →
Yes — and since July 2025, state law guarantees one ADU by right, no board hearing. Strafford's ordinance (unchanged since 2017) still says a Zoning Board special exception is required, but state law overrides it. Under RSA 674:72 (as amended effective July 1, 2025), one accessory dwelling unit — attached or detached — is allowed by right on single-family lots statewide.
750 sq ft — attached or detached. State law doesn't let any town cap ADU size below 750 sq ft.
Attached or detached (detached gated on full lot minimum). Since July 1, 2025, state law allows detached ADUs by right statewide — town provisions that prohibited them are superseded.
Required — "adequate off-street"; count unstated. State law caps what any town can require at one additional space, located on- or off-site at the owner's choice.
Required — in either the ADU or the primary home. Where owner-occupancy is required, state law lets the owner choose which unit to live in.