Carroll County · New Hampshire
ADU rules in Effingham, NH
Effingham is a Carroll County town on the Maine line, home to Province Lake.
Effingham 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 Effingham.
Effingham permits an ADU in every district with a building permit and the town ADU checklist. A detached ADU needs a 2-acre lot under the town text.
- Size limit
- Max 1,200 sq ft gross floor area (open decks excluded); max 2 bedrooms
- Where it can go
- Attached/interior (incl. inside a preexisting detached structure) or detached
- Owner on site
- Owner must live in the house or the ADU
- Parking
- 1 space per ADU, to the rear or side where feasible
- Approval
- Permitted (P) in all districts; building permit plus ADU checklist
- Rentals
- Rental ADUs follow the same rules and need state safety inspections
- Water setback
- Province Lake District: 50 ft shoreline setback; NHDES shoreland permit within 250 ft
Allowed
- ApprovalEach ADU needs a building permit with a completed ADU checklist. Table 1 lists both attached/interior and detached ADUs as P in Rural/Agricultural, Village, Historic and Province Lake districts.§2304.A; Table 1 rows 2-3
- Attached or detachedAttached/interior means within or physically connected to the house, or completely inside a preexisting detached structure. Detached means none of those.§2303
- How manyOne attached/interior ADU or one detached ADU, in all districts, if septic, setbacks, water and other zoning rules are met.§2304.C
- Owner on siteEither the ADU or the main house must be owner-occupied.§2304.D
- SizeGross floor area up to 1,200 sq ft, not counting open decks. The ADU may be inside or attached to a larger structure. Maximum two bedrooms.§2304.F; §2304.I.4
- ParkingOne space per ADU. Where feasible, parking goes to the rear or sides, not between the front lot line and the front of the building.§2304.G
- LotAttached/interior ADUs need no extra land. Detached ADUs are allowed only on lots meeting the 2-acre minimum lot size and all setbacks.§2304.H
- DesignNo manufactured homes, RVs or campers as ADUs. Attached ADUs need their own entrance or access through a shared common space, and the town may not limit the choice. A detached ADU should be to the rear or side of the house when possible. One driveway or curb cut per lot of record.§2304.E, I.1-3, J
- SepticADU must meet septic, water and setback rules under RSA 485-A:38. Structures that need a building permit must meet the Effingham Health Ordinance, and new or replacement septic systems need NHDES approval.§2304.C; §609
- RentalsRental ADUs follow the same rules as non-rental ADUs and must meet state safety and inspection rules. No short-term-rental clause in Art. 23. The 2026 checklist adds that rental units need Planning Board Site Plan Review and a yearly safety inspection; that is on the checklist, not in the ordinance text.§2305; ADU Checklist Rev. 3/17/26
- OtherHistoric District ADUs must follow Historic District rules. ADUs are not allowed on rented or leased land.§2304.N, P
- ShorelandRSA 483-B applies to all shoreland property; any work within NHDES's 250 ft jurisdiction needs proof of an NHDES permit before a town building permit. Province Lake District: lots within 300 ft of Province Lake's mean high water; 50 ft shoreline structure setback. New lots on public water need at least 150 ft of shore frontage.§401 PLD; §402 table; §608
- State lawThe town text requires a 2-acre lot for a detached ADU. State law bars added lot-size rules beyond those for the house.RSA 674:72, I
Not allowed
- Not allowedNo sale of the ADU separate from the main house.§2304.L
- Not allowedNo condominium conveyance of either the ADU or the main house.§2304.M
- Not allowedNo subdivision separating a detached ADU from the house unless all subdivision rules are met.§2304.K
- Not allowedNo manufactured home, RV or camper as an ADU.§2304.I.1
- Not allowedNo ADU on rented or leased land.§2304.P
- Not allowedOnly one dwelling per lot unless the ADU rules are met.§1014
Read 2026-11-15 from Zoning Ordinance of the Town of Effingham, NH 2000 (Rev 3/14/26 (cover; last amendment listed March 14, 2026). Interior page footers still read 'Rev 3/16/24'; Art. 23 is marked [Amended 2018, 2026].). Anything not listed here, we check with the Effingham land-use office for your lot.
Setbacks
Front, side and rear in Effingham.
NH RSA 674:71-73 (HB 577) - one attached or detached ADU by right on a single-family lot
Effingham's dimensional table, as printed in the ordinance.
| District | Front | Side | Rear | Lot / cover / height |
|---|---|---|---|---|
| R/AprimaryRural/Agricultural§402 table; §606; §607; §708. R/A frontage 200 ft. R/A accessory buildings: One storage building up to 100 sq ft and 14 ft tall may sit in a side/rear setback, no closer than 15 ft (§607). | 50 ft | 30 ft | 50 ft | 2 acres · No general limit; non-conforming lots of 1 acre or less limited to 20% structure footprint (§708) · Height 35 ft |
| VODVillage District (Village Overlay)§402 table; §606. VOD frontage 200 ft. | 35 ft | 25 ft | 50 ft | 2 acres · Same as R/A note (§708) · Height 35 ft |
| HDHistoric District§402 table; §606; Art. 15. HD frontage 200 ft. | 35 ft | 25 ft | 50 ft | 2 acres · Same as R/A note (§708) · Height 35 ft |
| PLDProvince Lake District§402 table; §606. PLD frontage 200 ft (150 ft min shore frontage for new lots on public water). | 30 ft | 20 ft | 30 ft | 2 acres · Same as R/A note (§708) · Height 35 ft |
Verified 2026-11-15 against Zoning Ordinance of the Town of Effingham, NH 2000. Towns amend ordinances, so confirm with the land-use office before you build. Official source
FAQ
ADUs in Effingham.
- How big can an ADU be in Effingham?
- Max 1,200 sq ft gross floor area (open decks excluded); max 2 bedrooms, per §2304.F; §2304.I.4 as read 2026-11-15.
- Does the owner have to live on the lot in Effingham?
- Owner must live in the house or the ADU (§2304.D).
- Can an ADU in Effingham be detached?
- Attached/interior (incl. inside a preexisting detached structure) or detached, under §2303.
Planning an ADU in Effingham?
Call (978) 987-0089 and we will read the ordinance against your lot. See the ADU models