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

New Hampshire law requires a building permit before covered construction or renovation in Sullivan County, and the work must comply with the state building and fire codes^1,7. Municipal enforcement arrangements vary: a local enforcement agency administers building permits and inspections where established, while the state fire marshal may enforce the building code upon written municipal request where no local agency or qualified third-party contract exists². The code in effect when the building-permit application is received governs the permitted work². Ask the parcel's municipality which building-permit application, inspections and fee schedule apply².

Sullivan County's FAQ directs building, fire and zoning questions to municipal or state offices; county administration is not the building-permit counter for an ordinary parcel¹³. Contact the parcel's town or city about its building-permit process and inspections². In Claremont, most building, renovation and demolition activities require a city building permit; listed exemptions still remain subject to other code and ordinance requirements¹⁴. Claremont's Building Safety and Codes Department is the building-permit contact for property inside Claremont¹⁵. NHDES remains the septic-plan approval authority throughout Sullivan County, including Claremont, and municipal health officers may impose additional septic rules^5,6. Building-permit fees follow the applicable local schedule².

Sullivan County has no countywide zoning ordinance; parcel rules depend on the municipality and zoning district^3,4. State zoning authority does not supply a parcel's district map or dimensional standards; obtain those from the municipality¹⁶. In Grantham, RR3 lots require at least 5 acres and 300 feet of frontage, excluding water bodies, wetland soils and slopes over 20% from the lot-area calculation; Central Village Residential lots require 0.4 acre and 100 feet of frontage with similar exclusions¹⁷. Grantham RR1 requires a 35-foot front setback and 10-foot side and rear setbacks, with 35 feet from both rights-of-way on corner lots¹⁷. Municipalities with zoning must allow one attached or detached accessory dwelling unit by right in districts allowing single-family dwellings, subject to applicable building, water and wastewater requirements¹⁸. The ADU space rule limits how low a municipality may set its maximum; it does not establish a statewide minimum dwelling size¹⁸.

NHDES must approve septic plans before construction unless a stated statutory exception applies, while municipal health officers may also regulate local subsurface systems^6,8. The installed system cannot be covered or used until NHDES or an authorized agent gives final approval⁸. Once operating, the tank must be inspected often enough to be pumped when combined sludge and surface scum reach one-third of its depth¹⁹. Sullivan County soils deserve early attention because only 9.2% are rated without severe limitations for a conventional drain field²⁰. A composting or incinerating toilet avoids department approval only in a structure with neither internal plumbing nor supplied water¹⁹. Contact NHDES Land Resource Management for the state process⁵.

We could not confirm a general private-parcel RV-living rule for Sullivan County; ask the parcel's municipal zoning office about occupancy during construction⁴. In Newport, a manufactured home or travel trailer at a construction site needs Zoning Board of Adjustment special-exception approval, for up to one year with a possible additional one-year extension²¹. New Hampshire recreational campgrounds allow temporary recreational occupancy, not permanent year-round residency; that rule does not establish permission to live in an RV on a private homesite⁹. Grantham recreational camping parks limit occupancy to 120 days in a 12-month period¹⁷. Effective September 13, 2026, municipalities may permit qualifying tiny houses, tiny houses on wheels or yurts as homes or ADUs, subject to local land-use and state water and wastewater rules; municipal permission is not automatic¹⁰. A qualifying tiny house is at most 600 square feet excluding lofts and must meet the tiny-home building-code provisions on a stable ground surface or foundation¹⁰.

1. Identify the parcel's town or city and obtain its zoning map, district standards and land-use approvals⁴.

1. Ask that municipality which building-permit application, building inspections and fee schedule apply².

1. Have the septic site evaluated early and submit the septic design to NHDES before construction^8,20.

1. Obtain any required municipal subdivision or site-plan approval²².

1. Obtain the building permit before starting covered construction¹.

1. Schedule required building inspections and the final septic inspection; obtain any locally required certificate of occupancy before moving in^2,8,23.

Confirm the municipality and zoning district first, because building-permit administration, allowed uses, setbacks and lot standards are local rather than uniform across Sullivan County^3,4. Verify legal road access and ask the town or state road authority whether a driveway permit is required; we could not confirm one rule covering every Sullivan County road. Ask the municipality about floodplain development because we could not confirm one countywide process. Test the septic concept before choosing a homesite: only 9.2% of county soils are rated without severe limitations for a conventional drain field²⁰. For a private well, New Hampshire requires the contractor to file a completion record within 90 days, but the statewide rule does not establish a universal construction permit for every ordinary well¹². Budget for an effective property-tax rate near 2.4% and a median annual bill near $5,616²⁰.