Sullivan County, New York requires a building permit for most new construction, with the town or village that has jurisdiction administering the state code and permit process1. Zoning is also set town by town rather than countywide, so what you can build depends on the municipality containing the parcel2. Septic review can involve a local or state health authority and, in specified watershed areas, NYC DEP3.
At a glance
- Building permit
- Required for most new construction; apply through the town or village with jurisdiction1
- Zoning
- Set town by town, not countywide2
- Septic authority
- State design standards (NYSDOH Appendix 75-A), administered locally; NYC DEP adds review in the watershed4
- Owner-builder exemption
- Not confirmed — ask your town's building department5
- Septic-friendly soil
- Only 0.6% of the county's soil has no severe limits for a conventional drain field6
- Farmland value
- About $5,224 per acre7
- Property tax
- 2.2% effective rate, about $5,082/yr median bill89
- Manufactured home
- Permit, certified installer and occupancy approval required; local zoning may be stricter10
Who to call
Planning & zoning
Sullivan County Division of Planning, Community Development and Environmental Management
Countywide land-use policy, technical assistance to Sullivan County's towns, and subdivision plat referrals; does not issue building permits or set zoning itself
100 North Street, PO Box 5012, Monticello, NY 12701
Building permits
Town of Thompson Building, Planning & Zoning Department
Building permits, plan review, code enforcement, certificates of occupancy and zoning/planning-board and ZBA filings for the Town of Thompson (includes Monticello) — one of Sullivan County's 15 towns, used here as a representative example; other towns run their own offices
4052 New York 42, Monticello, NY 12701
Health department
Sullivan County Public Health Department
County health department front desk; connects callers to the right program, including septic/onsite wastewater questions, for their part of Sullivan County
50 Community Lane, PO Box 590 Liberty, New York 12754
Roads & driveways
Sullivan County Division of Public Works
Road Access Applications for new or relocated driveways, and oversize/overweight permits, on Sullivan County roads (not town or state roads)
100 North Street, Monticello, NY 12701
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 Sullivan County, New York?
Yes: Sullivan County follows the New York State Uniform Fire Prevention and Building Code, which requires a building permit for work that must conform to the Uniform Code or Energy Code111. The 2025 Uniform Code took effect on December 31, 2025, and local authorities may impose more restrictive standards where authorized12. A local authority may exempt listed minor work, including qualifying one-story detached sheds, playhouses or similar accessory structures no larger than 144 square feet, but exempt work must still comply with the codes11. Permit fees vary by project and local authority, so obtain the current municipal fee schedule13. Construction inspections apply to permitted work, and a certificate of occupancy or compliance is required before covered work is occupied1415.
Who issues building permits in Sullivan County, and how do you reach them?
Building permits in Sullivan County are administered by the town or village with jurisdiction under the New York State Uniform Code1. Sullivan County contains 15 towns, 7 villages and more than 30 hamlets, so identify the parcel's municipality before looking for an application or fee schedule16. The county Planning Division assists local municipalities with land-use policy, but its page does not identify it as a building-permit office16. In the Town of Thompson, the Building, Planning & Zoning Department reviews plans, issues building permits and certificates of occupancy, and can be reached at (845) 794-2500 ext. 32117. Thompson requires the application, site plan, construction plans, insurance or CE-200 documentation, applicable board approvals and any required water or sewer district approval before work begins; that process is town-specific1819.
Does Sullivan County have zoning?
Zoning in Sullivan County is adopted and administered at the town or village level rather than through one uniform countywide code2. The Town of Thompson, for example, has its own zoning chapter, and its Building, Planning & Zoning Department enforces town rules governing building, zoning and other real-property uses220. That town-specific evidence does not establish the rules in another Sullivan County municipality20. We could not confirm one countywide rule for RV occupancy, tiny homes, minimum dwelling size, lot size, setbacks, lot coverage or building height. Ask the municipality's zoning office for the parcel's district, use table and dimensional schedule before making an offer. The Sullivan County Planning Division can help with land-use information and municipal contacts, but the applicable decision comes from the town or village16.
How do septic permits work in Sullivan County?
Sullivan County septic review can involve a New York State Department of Health district office or county health department, while NYC DEP also regulates specified sewage projects in the county's Arkville watershed region3. A system discharging less than 1,000 gallons per day of ordinary sewage to groundwater does not need a state SPDES permit, but health-department approval may still be required before construction and other approvals may apply21. Only 0.6% of Sullivan County land has soil without severe limitations for a conventional drain field, so establish septic feasibility before fixing a house location or purchase plan6. Start with Sullivan County Public Health, whose front desk will connect callers to the right program or resource22. We could not confirm from the available county material whether Public Health issues every residential septic approval directly, so ask which health authority and watershed review apply to the parcel before ordering a design.
Can you live in an RV or tiny home on your land in Sullivan County?
We could not confirm one countywide rule allowing or banning RV or tiny-home living in Sullivan County; zoning is administered town by town2. A certificate of occupancy or compliance is required for work that needed a building permit and when the general occupancy classification changes15. Manufactured-home installation, alteration and repair require a building permit, a certified installer and occupancy approval, while local zoning may impose stricter standards10. Those manufactured-home rules do not answer whether a municipality allows a tiny home or residential RV on a particular lot. Ask the parcel's town or village about the proposed structure and use before buying; in Thompson, contact the Building, Planning & Zoning Department at (845) 794-2500 ext. 32117.
Building a home in Sullivan County: the steps, in order
- Identify the town or village with jurisdiction, because municipal zoning and permit administration determine the application path12.
- Confirm the zoning district and proposed use with that municipality before commissioning plans2.
- Establish septic feasibility early: only 0.6% of county soils have no severe conventional-drain-field limitation, and the approving health or watershed authority depends on location63.
- Submit the work location, tax map number, scope, occupancy classification and acceptable construction documents required by the state process to the local authority23. Thompson applicants must also supply its listed local documents and approvals before starting work18.
- Keep permitted work accessible for required construction inspections and request each inspection when ready14.
- Obtain the certificate of occupancy or compliance before using covered work15.
- For a new or relocated driveway on a county road, contact Sullivan County Public Works at (845) 807-0283 for the Road Access Application24.
What to check before you buy land in Sullivan County
Confirm septic feasibility first: only 0.6% of Sullivan County soil has no severe limitations for a conventional drain field6. We could not confirm one countywide floodplain-development process, so ask the municipal building office which floodplain review applies to the parcel. Determine who maintains the frontage road: Sullivan County has county, state, town and private roads, and County Public Works supplies access applications for new or relocated driveways on county roads24. If land is being divided, New York's realty-subdivision rule can cover the tract when a fifth residential lot is offered within three years of the first offering, including the previously sold lots25. Sullivan County's effective property-tax rate is about 2.2%, with a median annual bill near $5,082 and a typical home value around $328,9908926. The land is 89.1% wooded, and 76.5% is at a slope of 15% or less, so evaluate clearing, grade and access on the actual homesite2728.
Watch-outs
- Sullivan County has no confirmed owner-builder exemption from the town permit process — ask your specific town's building department before assuming you can self-permit as an owner-builder5.
- If your land is in the New York City water supply watershed (the west-of-Hudson part of Sullivan County), NYC DEP septic review adds another approval on top of the state and local process4.
- Zoning, RV and tiny-home rules are set by your specific Sullivan County town, not the county government — confirm with that town before you buy or place a structure2.
Sources
- NYS Department of State - Uniform Fire Prevention and Building Code (2026 county census)
- Town of Thompson, NY - Chapter 250 Zoning (eCode360) (2026 county census)
- Jurisdictions of Other Agencies, quoted and re-checked
- NYS Department of Health - Septic Systems (2026 county census)
- (2026 county census)
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): 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
- Division of Building Standards and Codes Frequently Asked Questions, quoted and re-checked
- Part 1203 Uniform Code and the Energy Code: Minimum Standards for Administration and Enforcement (New York statewide rule), quoted and re-checked
- Notice of Adoption: 2025 Uniform Code, quoted and re-checked
- Department of State Administration and Enforcement Fee Schedule (New York statewide rule), quoted and re-checked
- Part 1203 Uniform Code and the Energy Code: Minimum Standards for Administration and Enforcement (New York statewide rule), quoted and re-checked
- Legal Memorandum LG03: NYS Uniform Fire Prevention and Building Code, quoted and re-checked
- Sullivan County Division of Planning, Community Development and Environmental Management (sullivanny.gov)
- Town of Thompson Building, Planning & Zoning Department (thompsonny.gov)
- Town of Thompson Application for Building Permit, quoted and re-checked
- Town of Thompson Application for Building Permit, quoted and re-checked
- Building, Planning & Zoning, quoted and re-checked
- State Pollutant Discharge Elimination System Permit Program, quoted and re-checked
- Sullivan County Public Health Department (sullivanny.gov)
- Administration and Enforcement of the Uniform Code (New York statewide rule), quoted and re-checked
- Sullivan County Division of Public Works (sullivanny.gov)
- REALTY SUBDIVISIONS: Frequently Asked Questions, quoted and re-checked
- Typical home value (Zillow): Bolthole Index county data
- Wooded share of land: Bolthole Index county data
- Share of land at 15% slope or less: Bolthole Index county data
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.