Building permits, zoning and septic rules in Franklin County, Massachusetts

Yes, a building permit is required everywhere in Franklin County under the statewide Massachusetts building code (780 CMR), but there is no county-level office that issues it — Franklin County has no county government, so permits are issued and enforced by each individual town's building inspector¹. In Greenfield, the county's largest city and traditional county seat, the Building Inspections Department administers state building, electrical, plumbing and gas codes and enforces the city's own zoning ordinance on top of them⁷. If you buy land in a different Franklin County town, expect a similar process at that town's own building department rather than Greenfield's. Many smaller towns share inspectors: the Franklin County Cooperative Inspection Program provides state-mandated building, electrical and plumbing/gas inspection services, or a subset of them, to 18 Franklin County towns⁸. Homeowners get one statewide break: an owner may apply for a permit on their own primary residence under a homeowner exemption in the building code, without needing a licensed construction supervisor, though a contractor cannot use this exemption⁵.

Because Franklin County has no county government, there is no single county building department to call¹. Greenfield's Building Inspections Department is one working example: it is reachable at 413-772-1404, and permit applications can be mailed to City Hall at 14 Court Square or dropped off at the department's office at 20 Sanderson Street⁷. Zoning applications and land-use permit questions in Greenfield go to the separate Planning & Development Department, which assists applicants with land use permits and the municipal boards and commissions that review them⁹. Every one of Franklin County's other towns has its own equivalent offices or shares inspection services through the Franklin County Cooperative Inspection Program, which also handles zoning enforcement in 16 towns⁸. Confirm the right town before you call, since Greenfield's numbers only apply inside Greenfield; septic permits stay with each town's Board of Health either way.

Franklin County itself has no zoning power because it has no county government; Massachusetts cities and towns adopt the zoning ordinances and bylaws that regulate land, buildings and structures^2,4. The zoning district, allowed uses, dimensional controls and enforcement authority therefore vary by municipality across Franklin County⁴. In Greenfield, the Planning & Development Department administers the city's own zoning ordinance and helps applicants with land-use permits⁹. Local zoning cannot regulate the interior area of a single-family home⁶. A single accessory dwelling unit is allowed by right in a single-family zoning district, subject to reasonable local rules and a maximum area of the lesser of half the main home's floor area or 900 square feet⁶. A town may also restrict or prohibit short-term rental of an accessory dwelling unit⁴.

Septic systems throughout Franklin County follow the statewide Title 5 code (310 CMR 15.000), but the permit itself is issued and enforced locally by each town's own Board of Health rather than by any county or state office³. In Greenfield, the Health Department reviews and assesses septic systems and coordinates with the DPW on safe sewer and water supplies¹⁰. Under Massachusetts law the local board of health must act on a completed septic application within 45 days, and a complete application includes deep observation holes and percolation test results¹¹. Soil is the practical constraint here: only about 1.4% of Franklin County's soils are rated without severe limits for a conventional septic drain field in USDA's survey, so plan on a percolation test and a real chance you will need an engineered, mound or other alternative Title 5 system rather than a standard gravity field^3,12. One narrow statewide rule can override a septic plan: if your parcel abuts a street where the town has already installed both a public drain and a public sewer, state law requires you to connect your plumbing to that sewer instead of using a septic system — this does not create a general rule requiring a sewer connection on land with no public sewer nearby¹³.

The applicable zoning rules for an RV or tiny house vary by Franklin County municipality, including local districts and dimensional controls⁴. We could not confirm a Franklin County-wide rule for long-term RV occupancy, temporary camping or tiny-home occupancy, so ask the planning or zoning office in the town where the parcel lies. The statewide seasonal-community tiny-house provision is conditional on local adoption and does not by itself establish permission on a Franklin County parcel¹⁴. Massachusetts does allow an owner whose residence was destroyed by fire or another natural disaster to place and occupy a manufactured home on that site for up to 12 months while rebuilding, subject to the state sanitary code⁶. If the proposed tiny home is an accessory dwelling unit, a town may restrict or prohibit its use as a short-term rental⁴.

1. Identify which Franklin County town your land is in, since building, zoning and septic rules are set entirely by that town, not by the county².
2. Contact that town's planning or zoning office for a preliminary consultation before you design anything; in Greenfield this is the Planning & Development Department⁹.
3. Have your soil tested for septic suitability early — under 1.4% of Franklin County's soils are free of severe limits for a conventional drain field, so many properties need an engineered or alternative Title 5 system^3,12.
4. Apply for your septic (Title 5) permit through your town's Board of Health, such as Greenfield's Health Department¹⁰.
5. Apply for your building permit through your town's building inspector once septic and zoning approvals are in hand; in Greenfield that is the Building Inspections Department⁷.
6. If you are the homeowner, ask about the owner-builder homeowner exemption, which lets you pull your own permit without a licensed construction supervisor for your primary residence⁵.
7. Schedule required inspections during construction and apply for an occupancy permit from the building inspector once work is complete.

Soils and septic are the biggest practical constraint: fewer than 1.4% of Franklin County's soils are rated free of severe limits for a conventional drain field, so get a percolation test before you commit to a price¹². The county is heavily wooded and mostly gentle, with about 86.6% forest cover and 62.1% of land at 15% slope or less¹². It gets about 49.1 inches of precipitation a year and sits in severe drought in roughly 5% of years¹². The nearest city of 100,000 or more people is about 28 miles away in straight-line distance¹². Home values run high for a rural county, with typical homes around $379,656 and farmland averaging about $8,637 an acre¹². Budget for property taxes too: the effective rate runs about 1.5%, with a median annual bill around $4,595, and typical homeowners insurance runs about $1,435 a year¹². If you plan to farm or homestead commercially, Massachusetts's statewide agricultural-use protection can shield qualifying farm land and structures from unreasonable local zoning restriction, subject to minimum parcel size and sales thresholds⁶.