| Max size | 950 sq ftconfirmed with the town |
|---|---|
| Min size | No town minimumbuild as small as code allows |
| Bedrooms | Up to 2confirmed with the town |
| Type | Attached or detachedgarage conversions allowed |
| Parking | 1 Spot for ADUconfirmed with the town |
| Owner-occupancy | Requiredin either the ADU or the primary home |
| Short-term rental | Short-term rental barredwritten into the ADU definition |
| 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 Salem:
Salem's own posted ordinance text has what looks like a drafting error — it doesn't clearly say you get to CHOOSE between a private entrance or one through shared common space. State law is clear that the choice is yours, not the town's. If a Salem permit reviewer tries to mandate one specific type of entrance citing this clause, point them to RSA 674:72, III and ask the Planning Department to confirm the intended reading (or fix the typo).
Salem's ordinance only describes an on-lot 'off-street' space and doesn't mention the state-law alternative. If your lot can't fit an extra space, state law gives you the right to satisfy the requirement with a legally dedicated off-site parking spot instead — Salem's silence on this doesn't take that right away.
State law lets Salem require an owner-occupant, but it doesn't say anything about trusts or LLCs. Salem added its own rule reaching through those entities to a human beneficiary or member. It's a reasonable anti-flip/anti-investor measure and doesn't specify WHICH unit (so it tracks the spirit of the state law), but whether it's something the statute actually authorizes for entity-owned property hasn't been tested — flag it for an attorney if your property is held in a trust or LLC.
CONFIRMED WITH THE TOWN (August 14, 2026) — ADUs allowed: 1; maximum size 950 sq ft; up to 2 bedrooms; impact fees: $5,884-fees to cover schools, saftey, traffic, regulations; parking: 1 Spot for ADU; detached-unit distance rule: No regs for a min or max distance from existing structure; setbacks: Residential- 15' side, 30' front/rear. Rural 30' front/side/rear. Town contact: Bridget-Planning Dept..
Pat confirmed requirments on August 12, 2026
Salem allows one accessory dwelling unit (ADU) by right on any lot with a single-family home, in every zoning district where single-family homes are allowed — no special exception, conditional use permit, or Planning/Zoning Board hearing required, just a building permit. This is confirmed directly in the Town's official Permitted Uses Table (Chapter 490, Attachment 1). On August 29, 2025, Salem's Town Council amended §490-801 and the related definitions in §490-107 specifically to catch the ordinance up to the new state law (RSA 674:71-73 as amended by HB 577, effective July 1, 2025). The biggest change: Salem's old rule flatly banned detached ADUs ('Detached accessory apartments are not allowed') — that ban is gone. Salem now defines and allows both 'attached' ADUs (inside or connected to the house, or built into a pre-existing detached structure like a garage) and true 'detached' ADUs (freestanding new construction). The town also cut its parking requirement from 4 spaces down to the state-law maximum of 1 additional space, and softened its old mandatory 'exterior appearance must match the house' rule into a non-binding recommendation. What still doesn't quite match the state law: (1) the ordinance's entrance-access clause for attached ADUs reads as a garbled single requirement rather than clearly giving you the choice of a private or shared entrance that state law guarantees; (2) the parking rule doesn't mention your state-law right to satisfy it with an off-site dedicated space instead of an on-lot one; (3) Salem added an occupancy rule reaching through trust/LLC ownership to a human beneficiary, which isn't explicitly covered by the statute. On the plus side, Salem's caps track the state maximums exactly (950 sq ft, 2 bedrooms), doesn't require a pre-existing home before you can add an ADU, allows converting nonconforming structures like old garages regardless of their setback issues, and doesn't impose extra septic requirements beyond RSA 485-A:38. One important catch for research accuracy: Salem's ordinance is ALSO posted on eCode360 (ecode360.com/27553341), and that copy is out of date — it still shows the pre-August-2025 rules (detached ADUs banned, 4 parking spaces, mandatory interior door). Anyone searching 'Salem NH ADU ordinance' online is likely to land on that stale eCode360 page first. The Town's own official Chapter 490 zoning PDF (linked from salemnh.gov/1270/Accessory-Dwelling-Units-ADUs) is the current, authoritative text used for this extraction. Separately, ADUs in Salem may NOT be used as short-term rentals (Airbnb-type stays) — that's baked into the definition of 'accessory dwelling unit' itself, and state law doesn't override that since HB 577 doesn't address STR use of ADUs.
Primary source: Town zoning ordinance (PDF) — §490-801 and the related §490-107 definitions ('ACCESSORY…
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Get My Free Salem ADU Report →House Bill 577 (2025) amended RSA 674:72, effective July 1, 2025. Wherever Salem's ordinance is stricter than this floor, the state law controls. Read the full NH ADU law explainer →
Yes — Salem allows one accessory dwelling unit, attached OR detached, by right on any lot with a single-family dwelling. 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.
950 sq ft — confirmed with the town. State law doesn't let any town cap ADU size below 750 sq ft.
Attached or detached (garage conversions allowed). Since July 1, 2025, state law allows detached ADUs by right statewide — town provisions that prohibited them are superseded.
1 Spot for ADU — 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.