| Max size | 750 sq ftconfirmed with the town |
|---|---|
| Min size | For attatched, the accessory dwelling unit…confirmed with the town |
| Bedrooms | Up to 2confirmed with the town |
| Type | Detached implied; attached unclearno ordinance text on file |
| Parking | 1 spot onsiteconfirmed with the town |
| Owner-occupancy | Requiredin either the ADU or the primary home |
| Short-term rental | Not capturedpending verification |
| 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 Exeter:
State law guarantees at least one ADU by right in every district that allows single-family homes. Only the R2 zone has come up in connection with Exeter ADUs, and the town's current ordinance text could not be confirmed for other zones — it's unclear whether R2 is genuinely the only district where ADUs are allowed (which state law would override) or simply the zone of the specific property being discussed. Treat district details as pending verification.
State law requires towns to allow by-right conversion of an existing garage or other structure into an ADU, without a board hearing. If Exeter still requires Zoning Board approval for conversions, state law overrides that. The statement on record dates from mid-2024, a year before the state law took effect, so town practice may have since changed — treat the town's current process as pending verification.
State law bars towns from making a family relationship a condition of ADU status. Exeter's described practice doesn't look like the town restricting anyone's ADU rights — it reads more like an alternate, less-regulated pathway the town offers for family members. But because it touches the exact provision the 2025 law was written to police, it needs an attorney or the actual ordinance text to confirm it isn't functioning as a backdoor restriction on rental ADUs.
CONFIRMED WITH THE TOWN (August 14,2026) — ADUs allowed: 1; maximum size 750 sq ft; minimum size For attatched, the accessory dwelling unit shall be limited to less than half of the finished floor area of the principal structure, but in no case shall the accessory dwelling unit be restricted to less than 750 square feet; up to 2 bedrooms; impact fees: None unless in a School or recreation district, or on sewer/water; parking: 1 spot onsite; detached-unit distance rule: None; setbacks: R-2 15sides, 25 front, 25 rear but could change depending on non-conforming lot. Town contact: Doug Eastman - Code Enforcement Officer 603-778-0591.
Pat confirmed requirements with Doug Eastman - Code Enforcement Officer on August 14, 2026
Start with what's certain: state law (RSA 674:71-73, as amended by HB 577 effective July 1, 2025) guarantees every Exeter homeowner in a district that allows single-family homes at least one ADU by right — attached or detached — with no special exception or conditional-use permit allowed for that one by-right unit, any town size cap no lower than 750 sq ft, at most one additional required parking space (on-site or off-site at the owner's choice), and no familial-relationship requirement. Exeter's town-specific picture is thinner: the town's current zoning ordinance text for ADUs could not be confirmed for this record, so the local details below come from conversations with the town's building department (July 2024 and December 2025) and should be treated as pending verification. What the town has said: ADUs are permitted, one unit must be owner-occupied, and as of 2024 staff described ADUs as 'permitted by right' with a maximum detached size of 750 sq ft — exactly the smallest cap state law allows a town to impose. But the same 2024 guidance also said a 'conversion' requires Zoning Board approval and that the R2 zone allows 'residential conversions... by special exception' — statements that are hard to reconcile with a by-right process, with each other, and (for conversions) with the state law's by-right conversion mandate, which overrides any such hearing requirement. There's also an unusual carve-out described for family-occupied units (treated as NOT an ADU, requiring a deed covenant instead, with full ADU criteria applying only to rental units) that needs ordinance-text confirmation. Because the most detailed local rules on record predate the July 1, 2025 state law by about a year, none of the size, district-scope, permit-process, or parking details should be treated as current with confidence — and wherever the town's older statements conflict with state law, state law controls. The December 2025 conversation added only fee and setback logistics, not ADU-specific rules. Town contact: Doug Eastman, Building Inspector (603-773-6113, deastman@exeternh.gov), with Kathleen Croteau as Administrative Assistant (603-773-6112, kcroteau@exeternh.gov), Town of Exeter, 10 Front Street, Exeter, NH 03833 — the Building Department welcomes calls about specific properties.
Get a free personalized report for your address in Exeter — including where the 2025 law works in your favor.
Get My Free Exeter ADU Report →House Bill 577 (2025) amended RSA 674:72, effective July 1, 2025. Wherever Exeter's ordinance is stricter than this floor, the state law controls. Read the full NH ADU law explainer →
Yes — state law guarantees Exeter homeowners at least one ADU by right, attached or detached, wherever single-family homes are allowed, and the town's building department describes ADUs as permitted by right. The town's own current ordinance text could not be confirmed, so treat local details as pending verification. 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 — confirmed with the town. State law doesn't let any town cap ADU size below 750 sq ft.
Detached implied; attached unclear (no ordinance text on file). Since July 1, 2025, state law allows detached ADUs by right statewide — town provisions that prohibited them are superseded.
1 spot onsite — confirmed with the town. 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.