Strafford County · New Hampshire
ADU rules in Rollinsford, NH
Rollinsford is a Strafford County town on the Salmon Falls River.
Rollinsford is in our service area. This page covers what the town ordinance says about ADUs.
Town ADU rules
What’s allowed on your lot in Rollinsford.
Rollinsford repealed and replaced its ADU section in March 2026. One ADU of up to 750 sq ft is allowed by right, attached or detached.
- Size limit
- Max 750 sq ft of living space and 2 bedrooms
- Where it can go
- Attached or detached; conversions of existing structures such as detached garages allowed
- Owner on site
- Owner must live in one of the units as a principal residence
- Parking
- 1 additional space for the ADU
- Approval
- By right; building permit and Building Inspector occupancy permit
- Water setback
- 250 ft from the Salmon Falls River; 50 ft from year-round streams and from wetlands
Allowed
- ApprovalADUs are allowed in all districts that permit single-family dwellings. One ADU, attached or detached, is allowed as a matter of right. Table 6.9 marks ADU 'P' in UR, SR1, SR2, CR, OSD, C1, C2 and Ind.§8.1.3.a.1; Table 6.9 line A1
- Attached or detachedAttached = within or physically connected to the house, or completely inside a preexisting detached structure. Detached = neither. ADUs may be built at the same time as the house.§2.1A-2.1C (Amended/Added March 2026)
- SepticSeptic for a house with an ADU must comply with NHDES. Water and sewage must be adequate under RSA 485-A:38, but separate systems are not required.§8.1.3.a.2, a.8
- How manyNo more than one ADU per single-family dwelling. ADUs prohibited on rented or leased land.§8.1.3.a.3
- OtherCondo conveyance of the ADU separate from the house is prohibited.§8.1.3.a.4
- DesignAttached ADUs need either their own entrance or access through a common space shared with the house.§8.1.3.a.5
- LotSingle-family rules (including lot coverage and HUD-based occupancy per bedroom) apply to the house plus ADU combined, but may not be stricter for ADUs than for any single-family use in the district.§8.1.3.a.6
- ParkingOne additional parking space is required for the ADU.§8.1.3.a.7
- Owner on siteOwner must occupy one of the units as a principal residence and give documentation to the Building Inspector.§8.1.3.a.9
- SizeMax 750 sq ft of total living space and max 2 bedrooms. No minimum stated.§8.1.3.a.10
- OtherADUs may be converted from existing structures, including detached garages, even if they violate current setbacks or lot coverage. The structure must have had prior building permit approval.§8.1.3.a.11, a.18
- OtherA separate electrical panel or service is not required.§8.1.3.a.12
- ApprovalOccupancy permit from the Building Inspector before occupancy; design and construction per the Town Building Code; appeals to the Zoning Board; violations $275 per day.§8.1.3.a.13-16
- OtherADUs prohibited where multiple single-family dwellings are attached, such as townhouses.§8.1.3.a.17
- ShorelandStructures at least 250 ft from the high water mark of the Salmon Falls River and 50 ft from the high water mark of any year-round stream. Wetland Conservation District: 25 ft natural undisturbed buffer, 25-50 ft graded/landscaped (no paving or parking), and 50 ft setback from wetlands for any structure needing a building permit. State RSA 483-B applies separately.Table 7 footnotes 8 and 10; §6.7.4.a-b
Not allowed
- Not allowedMore than one ADU per single-family dwelling.§8.1.3.a.3
- Not allowedADU on rented or leased land.§8.1.3.a.3
- Not allowedADU with townhouses or other attached single-family dwellings.§8.1.3.a.17
- Not allowedSeparate condo conveyance of the ADU.§8.1.3.a.4
- Not allowedADU over 750 sq ft or more than 2 bedrooms.§8.1.3.a.10
Read 2026-11-15 from Zoning Ordinance, Rollinsford, NH (town Google Drive folder linked from rollinsfordnh.gov/docs, file 'Rollinsford Zoning Ordinances 2026.pdf') (Cover: 'Amended: March 2005, ... March 2024, March 2026'; ADU section 'Repealed and Replaced March 2026'). Anything not listed here, we check with the Rollinsford land-use office for your lot.
Setbacks
Front, side and rear in Rollinsford.
NH RSA 674:71-73 (HB 577) - one attached or detached ADU by right on a single-family lot
Rollinsford's dimensional table, as printed in the ordinance.
| District | Front | Side | Rear | Lot / cover / height |
|---|---|---|---|---|
| URprimaryUrban ResidentialTable 7 (Section 7); Table 6.9. UR frontage Min lot width 100 ft (frontage at least 80% of width, fn 1). | 20 ft (3)(8) - need not exceed average of adjacent dwellings | 15 ft | 15 ft | 30,000 sq. ft. (1 acre if not served by municipal sewer and water, footnote 5); wetlands, steep slopes, easements excluded (fn 9) · 30% (building) · Height 35 ft / 2.5 stories |
| OSDOld Salmon FallsTable 7. OSD frontage Min lot width 100 ft. | * Average of buildings on either side | * Average of buildings on either side | * Average of buildings on either side | 15,000 sq. ft. (14) · 30% (building) · Height (14) - footnote 14 is not printed; footnote 13 says height is set by the structure existing March 11, 1997, or the average of neighbors on vacant lots |
| SR (SR1/SR2)Suburban ResidentialTable 7; Table 6.9 lists SR1 and SR2 columns, Table 7 has one SR row. SR (SR1/SR2) frontage Min lot width 200 ft. | 30 ft | 20 ft | 30 ft | 3 acres · 25% (building) · Height 35 ft / 2.5 stories |
| CRCountryside (Country) ResidentialTable 7. CR frontage Min lot width 200 ft. | 50 ft (8) | 25 ft | 25 ft | 4 acres · 20% (building) · Height 35 ft / 2.5 stories |
| IndIndustrial (Table 7 row 'Industrial/Mill')Table 7; Table 6.9; §8.21. Ind frontage Min lot width 200 ft. | 25 ft (100 ft along NH Route 4, fn 7) | 25 ft | 25 ft | 2 acres · 25% (building) · Height 40 ft |
Verified 2026-11-15 against Zoning Ordinance, Rollinsford, NH (town Google Drive folder linked from rollinsfordnh.gov/docs, file 'Rollinsford Zoning Ordinances 2026.pdf'). Towns amend ordinances, so confirm with the land-use office before you build. Official source
FAQ
ADUs in Rollinsford.
- How big can an ADU be in Rollinsford?
- Max 750 sq ft of living space and 2 bedrooms, per §8.1.3.a.10 as read 2026-11-15.
- Does the owner have to live on the lot in Rollinsford?
- Owner must live in one of the units as a principal residence (§8.1.3.a.9).
- Can an ADU in Rollinsford be detached?
- Attached or detached; conversions of existing structures such as detached garages allowed, under §2.1A-2.1C (Amended/Added March 2026).
Planning an ADU in Rollinsford?
Call (978) 987-0089 and we will read the ordinance against your lot. See the ADU models