Rockingham County · New Hampshire
ADU rules in Greenland, NH
Greenland is a Rockingham County town on Great Bay, next to Portsmouth.
This is a reference guide. Greenland is not on our service-area list, so call to ask whether we can take on a build there.
Town ADU rules
What’s allowed on your lot in Greenland.
Greenland permits an ADU of up to 1,200 sq ft and two bedrooms in its R, CA and CC districts, attached or detached.
- Size limit
- Max 1,200 sq ft of conditioned space, max two bedrooms
- Where it can go
- Part of the house or detached
- Owner on site
- Owner must live in one of the units
- Parking
- On-site parking required (no space count)
- Approval
- Permitted use (P) in R, CA and CC; septic sign-off, building permit and certificate of occupancy
- Water setback
- Structures 100 ft from tidal wetlands, 75 ft from surface water, 50 ft from inland wetlands
Allowed
- Attached or detachedThe ADU may be part of the house or a detached structure. 2026 definitions: an 'attached unit' is within or connected to the house, or completely inside a pre-existing detached structure. A 'detached unit' is neither.§3.7.11.3; §3.7.11 definitions ii-iii (03.2026)
- How manyOnly one ADU per lot.§3.7.11.8
- ApprovalADU is a permitted use (P) in Residential, Commercial A and Commercial C. Before work starts, the Town's authorized agent must approve septic and water in writing, then the building permit is issued. A certificate of occupancy is required before anyone moves in.§3.6 Table of Uses A.8; §3.7.11.6-3.7.11.7
- Owner on siteThe owner must live in one of the units and be the owner/landlord of the other.§3.7.11.1
- SizeMax 1,200 sq ft of conditioned space (assessed gross area). Max two bedrooms.§3.7.11.2 (03.2024, 03.2026)
- ParkingOn-site parking is required. No number of spaces is given.§3.7.11.4
- SepticBefore renovation or construction, the owner shows septic is adequate under State and Town standards (septic designer certification if asked) and that potable water is adequate.§3.7.11.6
- OtherThe ADU must meet the structural, water and sanitary standards for residential buildings. Dormitory-type facilities are prohibited. The property must conform to all other zoning.§3.7.11.5, 3.7.11.8
- ShorelandNo local shoreland overlay found; state RSA 483-B applies on its own terms. Wetlands Protection Ordinance structure setbacks: tidal wetlands 100 ft, surface water 75 ft, inland jurisdictional wetlands 50 ft. Vegetated buffer strip 25 ft, plus limited-cut areas to 100 ft (tidal), 75 ft (surface water) or 50 ft (inland). Setbacks/buffers do not apply to isolated wetlands of 3,000 sf or less that are not vernal pools (03.2026).§18.7.2; §18.8.2
Read 2026-11-15 from Town of Greenland, NH 2026 Zoning Ordinance (Cover: updated March ... 2024, 2025, 2026; pages marked 'Revised 06.2026'; §3.7.11 'Adopted March 2008, Amended 2016, 2017, 2024. 2026'). Anything not listed here, we check with the Greenland land-use office for your lot.
Setbacks
Front, side and rear in Greenland.
NH RSA 674:71-73 (HB 577) - one attached or detached ADU by right on a single-family lot
Greenland's dimensional table, as printed in the ordinance.
| District | Front | Side | Rear | Lot / cover / height |
|---|---|---|---|---|
| RprimaryResidential§4.2 Table of Dimensional Requirements; §4.3 notes 1, 2, 7, 8. R frontage 200 ft. R accessory buildings: Structures without masonry/concrete foundations, ≤64 sf: 10 ft side and rear (note 2). | 30 ft (Route 33 lots: measured from State ROW) | 20 ft | 20 ft | 60,000 sf with 45,000 sf contiguous non-wetland soil (new duplex: 90,000 sf with 60,000 sf) · 20% max (footprint); 80% open space · Height 35 ft |
| CACommercial A (Existing Commercial)§4.2; §4.3. CA frontage 200 ft. CA accessory buildings: Note 2: ≤64 sf non-foundation structures 10 ft side/rear. | 30 ft (notes 1, 6) | 20 ft (50 ft for commercial use abutting R district; 25 ft abutting a residential use, note 4) | 20 ft (same note 4) | 60,000 sf with 45,000 sf contiguous non-wetland soil · 50% max (footprint); 50% open space · Height 35 ft |
| CCCommercial C (Highway)§4.2; §4.3. CC frontage 200 ft. CC accessory buildings: Note 2: ≤64 sf non-foundation structures 10 ft side/rear. | 30 ft (notes 1, 6) | 20 ft (note 4) | 20 ft (note 4) | 60,000 sf with 45,000 sf contiguous non-wetland soil · 50% max (footprint); 50% open space · Height 35 ft |
Verified 2026-11-15 against Town of Greenland, NH 2026 Zoning Ordinance. Towns amend ordinances, so confirm with the land-use office before you build. Official source
FAQ
ADUs in Greenland.
- How big can an ADU be in Greenland?
- Max 1,200 sq ft of conditioned space, max two bedrooms, per §3.7.11.2 (03.2024, 03.2026) as read 2026-11-15.
- Does the owner have to live on the lot in Greenland?
- Owner must live in one of the units (§3.7.11.1).
- Can an ADU in Greenland be detached?
- Part of the house or detached, under §3.7.11.3; §3.7.11 definitions ii-iii (03.2026).
Planning an ADU in Greenland?
Call (978) 987-0089 and we will say whether we can build there. See the ADU models