Building permits, zoning and land rules in Coos County, New Hampshire

Yes. Before covered construction, alteration, renovation, repair, removal, or demolition begins in Coos County, the responsible person must obtain a building permit, and the work must comply with New Hampshire's state building and fire codes^1,2. County zoning approval is also required before covered construction or occupancy in an unincorporated place³. Every building erected on leased land in an unincorporated town or unorganized place has a separate county building-permit requirement¹¹. We could not confirm who issues or inspects a building permit for an unincorporated one- or two-family home; ask the county office¹⁰.

For an unincorporated parcel, start with Coos County Administration Office & Unincorporated Places at 34 County Farm Road, PO Box 310, West Stewartstown, NH 03597, phone (603) 237-1920¹⁰. The County Commissioners or designee administer county zoning approvals³. Zoning applications cost $25 for new construction, $10 for renovations, or $100 after the fact; these are not confirmed building-permit fees¹². Ask who issues the building permit, performs inspections, and supplies occupancy paperwork. Owner-builders have no blanket permit exemption and must submit as-built energy certification before occupancy^6,7. Incorporated municipalities handle local building and zoning administration, while NHDES handles septic approval^4,5.

Coos County directly zones its unincorporated places; incorporated municipalities use separate local processes^3,4. An unincorporated building lot generally needs at least one acre, buildings may cover no more than 30% of the lot, and ordinary building height is capped at 35 feet³. Structures generally need 75 feet from a road right-of-way and 25 feet from side and rear lines³. Accessory dwellings require a county permit in the Management, General Development, and Resort Development districts⁹. We could not confirm a minimum dwelling floor area; ask the county office¹⁰. Most nonexempt development in the flood-prone overlay requires conditional-use review³.

A new Coos County septic system needs NHDES Construction Approval based on a licensed New Hampshire designer's plan⁵. Local requirements may also apply, and an approved system cannot be covered or used before final inspection and approval^13,14. Only 3.4% of county soils lack severe limits for a conventional drain field, so settle feasibility early¹⁵. Covered buildings must connect to a public sewer within 100 feet, subject to local distance changes or a qualifying waiver¹⁶. A privy needs local health approval, which may include NHDES review¹⁶. Composting or incinerating toilets avoid department approval only without internal plumbing or supplied water¹⁷.

The unincorporated-place ordinance treats campground occupancy as temporary and limits a campsite to 30 overnight visitors, but it does not answer whether an RV may be a long-term home on an ordinary parcel³. Ask the county office before buying for residential RV use¹⁰. New Hampshire lets a local authority permit a qualifying tiny house where single-family homes are allowed or as an accessory dwelling, subject to land-use, building-code, drinking-water, and wastewater rules⁸. A statutory tiny house has permanent living, sleeping, eating, cooking, and sanitation facilities and no more than 600 square feet excluding lofts⁸. That framework does not approve a particular parcel⁸.

1. Identify whether county or municipal land-use administration applies³.

1. Confirm district, overlays, setbacks, and floodplain status^3,10.

1. Establish septic feasibility and obtain NHDES Construction Approval⁵.

1. Obtain required zoning, subdivision, conditional-use, or site-plan approval^3,18.

1. Identify the issuer and obtain the building permit before covered work^1,10.

1. Obtain an NHDOT driveway permit for access to a state-controlled highway¹⁹.

1. Complete inspections and submit the energy certification before occupancy^6,20.

Confirm the parcel's legal place because county zoning governs unincorporated places while municipalities use separate processes⁴. Check the district, overlays, setbacks, coverage, and review requirements^3,18. Order septic feasibility early because only 3.4% of county soils avoid severe limits for a conventional drain field¹⁵. Check for public sewer within 100 feet and state-highway driveway approval^16,19. Flood-overlay development may require conditional-use review and federal floodplain standards³. Coos County is 94.2% wooded and 27.7% federal land, so verify boundaries, legal access, clearing constraints, and nearby public ownership¹⁵.