Zoning, building permits and septic rules in Town of Grantham, New Hampshire

Town of Grantham’s own rules

• Building permitRequired

  Accessory dwelling units in Grantham town (article VIII) only; no general building-permit rule was located

  • Applies only to accessory dwelling units; the ordinance says the ADU shall comply with the state building code and fire code regulations for construction.
  • Construction may proceed after the permit is issued.

  “A building permit and certificate of occupancy are required.”

• Certificate of occupancyRequired

  Accessory dwelling units in Grantham town (article VIII) only; no general certificate-of-occupancy rule was located

  • Applies only to accessory dwelling units.
  • Certificate of occupancy is issued after construction; use may begin once issued.

  “A building permit and certificate of occupancy are required.”

• Local zoningPresent

  All land inside Grantham town limits; Grantham town administers its own Grantham Zoning Ordinance

  • The ordinance is titled Grantham Zoning Ordinance, rev. March 10, 2026; the rev. date is a revision stamp, not an effective date.

  “The Town of Grantham, New Hampshire is divided into the following districts:”

• Zoning districtsPublished

  Zoning districts of Grantham town under the Grantham Zoning Ordinance

  • The table of contents names Article V-A, rural residential district one (RR1), and Article IV-C, manufactured housing parks; the revision history names RR2, RR3 and the central village district. Only RR1 dimensional text was captured.
  • The 'rev.' date on the ordinance is not an effective date.

  “The Town of Grantham, New Hampshire is divided into the following districts:”

• Minimum lot sizeSpecified

  Rural Residential District One (RR1, Article V-A) lots in Grantham town

  • No water bodies or wetland soils and no portion of slope areas of an incline greater than twenty (20) percent may be included in the minimum lot size.
  • District attribution: the lot and frontage text was captured after the RR1 permitted-uses list; the district heading was not re-opened.
  • RR2, RR3, Central Village and business districts not verified.

  minimum lot size: >= 1 acre (wetland and slope areas excluded) · minimum lot frontage on any street: >= 200 feet

  “The minimum area of any lot shall be one (1) acre in size. No water bodies or wetlands soils and no portion of slope areas of an incline greater than twenty (20) percent may be included in the minimum lot size.”

• Lot coverageSpecified

  Rural Residential District One (RR1, Article V-A) lots in Grantham town

  • District attribution as for minimum lot size.

  building coverage: <= 20 percent

  “The building coverage on any lot may not exceed twenty (20) percent.”

• Manufactured homesAllowed

  Single-family manufactured housing unit on a lot in the Rural Residential District One (RR1, Article V-A)

  • Limited to one dwelling or manufactured housing unit per lot.
  • Other districts (including manufactured housing parks under Article IV-C) were not verified.

  “Single-family Dwellings, Two-family Dwellings, or Single-family manufactured housing units, limited to one (1) dwelling or manufactured housing unit per lot.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Town of Grantham or Sullivan County directly.

• Owner-builder exemption — Owner-builders in Grantham town
• Building code adopted — Land inside Grantham town limits
• Inspections — New construction inside Grantham town limits
• Minimum dwelling size — Principal single-family dwellings inside Grantham town limits
• Building height — Structures inside Grantham town limits

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Off-grid gear

Going off-grid in Town of Grantham means bringing your own water and power. The kit we’d start with:

• Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
• Power Bluetti Solar generators and home battery backup for living off the grid.
• Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
• Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.

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