Franklin County, Massachusetts has no county government at all, so there is no county building department, zoning office or septic authority to call1. A building permit is required everywhere in the county under the statewide Massachusetts building code, but it is issued and enforced by each of the county's individual towns, not by the county1. Zoning is likewise adopted and enforced town by town under the state Zoning Act2, and septic systems statewide follow the Title 5 code (310 CMR 15.000) with permits issued by each town's Board of Health3. This guide uses Greenfield, the county's traditional county seat and largest city, as a worked example of what one Franklin County town requires; your own town's offices will differ.
At a glance
- Building permit
- Required statewide under 780 CMR, issued by each town, not the county1
- Zoning
- Rules, districts and dimensional controls vary by municipality4
- Septic
- State Title 5 code, permitted locally by each town's Board of Health3
- Owner-builder exemption
- Yes, for a homeowner's own primary residence under 780 CMR 110.R55
- Minimum home size
- No zoning ordinance statewide may regulate the interior area of a single-family home6
- Accessory dwelling unit
- Allowed by right in single-family zoning districts, but towns may restrict short-term rentals78
- Example: Greenfield building permit office
- City of Greenfield Building Inspections Department, 413-772-14049
Who to call
Building permits
City of Greenfield Building Inspections Department
Building, electrical, plumbing and gas permits and inspections for the City of Greenfield, used here as an example of one Franklin County town's building department
20 Sanderson Street, Greenfield, MA 01301
Zoning
City of Greenfield Planning & Development Department
Zoning administration, the Planning Board and the Zoning Board of Appeals for the City of Greenfield, used here as an example of one Franklin County town's zoning office
20 Sanderson Street, Greenfield, MA 01301
Health department
City of Greenfield Health Department (Board of Health)
Title 5 septic system review and other local health permitting for the City of Greenfield, used here as an example of one Franklin County town's Board of Health
20 Sanderson St., Greenfield, MA 01301
Contact details are copied from each office’s official page and were checked against it on September 29, 2026.
Do you need a building permit 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 them9. 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. 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.
Who issues building permits in Franklin County, and how do you reach them?
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 Street9. 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 them10. Every one of Franklin County's other towns has its own equivalent building and planning offices; confirm the right town before you call, since Greenfield's numbers only apply inside Greenfield.
Does Franklin County have zoning?
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 structures24. 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 permits10. 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 feet7. A town may also restrict or prohibit short-term rental of an accessory dwelling unit8.
How do septic permits work in Franklin County?
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 supplies11. 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 field123. 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.
Can you live in an RV or tiny home on your land in Franklin County?
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 code15. If the proposed tiny home is an accessory dwelling unit, a town may restrict or prohibit its use as a short-term rental8.
Building a home in Franklin County: the steps, in order
- 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.
- Contact that town's planning or zoning office for a preliminary consultation before you design anything; in Greenfield this is the Planning & Development Department10.
- 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 system123.
- Apply for your septic (Title 5) permit through your town's Board of Health, such as Greenfield's Health Department11.
- 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 Department9.
- 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.
- Schedule required inspections during construction and apply for an occupancy permit from the building inspector once work is complete.
What to check before you buy land in Franklin County
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 less1617. It gets about 49.1 inches of precipitation a year and sits in severe drought in roughly 5% of years1819. The nearest city of 100,000 or more people is about 28 miles away in straight-line distance20. Home values run high for a rural county, with typical homes around $379,656 and farmland averaging about $8,637 an acre2122. 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 year232425. 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 thresholds26.
Watch-outs
- Franklin County has no county government, so nothing here about Greenfield's offices, phone numbers or fees applies in any other Franklin County town; confirm the right town before you call1.
- Under 1.4% of Franklin County's soils are rated free of severe limits for a conventional septic drain field, so a percolation test before you buy is not optional in most of the county12.
- The state's tiny-house allowance for undersized lots only applies in municipalities designated "seasonal communities," and no Franklin County town is on that list, so it does not create a tiny-home right here14.
Sources
- Massachusetts State Building Code 780 CMR 51.00 (Residential Code) (2026 county census)
- Mass.gov - Massachusetts law about zoning (MGL Ch. 40A) (2026 county census)
- MassDEP - 310 CMR 15.000 Septic Systems (Title 5) (2026 county census)
- Massachusetts General Laws Chapter 40A, Section 1A, quoted and re-checked
- Mass.gov - Massachusetts law about home improvement (homeowner exemption) (2026 county census)
- General Law - Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
- Massachusetts General Laws Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
- Massachusetts General Laws Chapter 40A, Section 1A, quoted and re-checked
- City of Greenfield Building Inspections Department (greenfield-ma.gov)
- City of Greenfield Planning & Development Department (greenfield-ma.gov)
- City of Greenfield Health Department (Board of Health) (greenfield-ma.gov)
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Massachusetts General Laws Chapter 83, Section 5 (Massachusetts statewide rule), quoted and re-checked
- Massachusetts General Laws Chapter 23B, Section 32 (Massachusetts statewide rule), quoted and re-checked
- Massachusetts General Laws Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
- Wooded share of land: Bolthole Index county data
- Share of land at 15% slope or less: Bolthole Index county data
- Annual precipitation: Bolthole Index county data
- Share of years in severe drought: Bolthole Index county data
- Distance to the nearest metro area: Bolthole Index county data
- Typical home value (Zillow): Bolthole Index county data
- Farmland value per acre (USDA census): Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- Typical home insurance premium: Bolthole Index county data
- General Law - Chapter 40A, Section 3 (Massachusetts statewide rule), quoted and re-checked
Written September 29, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.