Building permits, zoning and septic rules in St. Lawrence County, New York

Yes. In St. Lawrence County, work that must conform to the New York State Uniform Code requires a building permit, although certain exceptions are allowed¹. The 2025 Uniform Code has applied to building-permit applications since December 31, 2025⁷. Applications must identify the location and scope of work, tax-map number, address and occupancy classification and include the applicable construction documents⁶. A local authority may expressly exempt listed categories, including certain detached one-story structures no larger than 144 square feet, but exempt work must still comply with the codes⁵. Ask the code-enforcement office for the parcel's town, village or city which exceptions it has adopted before starting a small project¹.

Start with the code-enforcement office for the parcel's town, village or city; the local program must identify who administers the Uniform Code and provide permits, inspections, stop-work procedures and occupancy certificates¹. Permit holders must keep covered work accessible and exposed until the municipality inspects and accepts it¹. If you are unsure which municipality covers a parcel, the St. Lawrence County Planning Department can help identify it and explain the county planning role, but it does not issue the local building permit⁸. Reach the Planning Department at 80 State Higway 310, Canton, New York 13617, phone 315-379-2292⁸. Certain projects with wider county, state or cross-boundary effects may also be referred to the County Planning Board; nearly 90% of projects it reviews are returned quickly for local action². The New York Department of State's published schedule lists $200 for a new one- or two-family home up to 1,500 square feet, plus $100 for each additional 1,000 square feet or fraction, and no fee for permit renewals; local departments may have their own schedules, so ask the local code office for its application and fees⁹.

St. Lawrence County does not supply one zoning answer for every parcel. Land-use rules and enforcement vary among towns, villages and the City of Ogdensburg, and 40 of the county's 47 municipalities have adopted some form of land-use management¹⁰. The county publishes an inventory of municipal zoning regulations, not a countywide zoning ordinance or parcel map; confirm the current district and rules with the relevant town, village or city⁴. Subdivision is also local: 26 municipalities enforce subdivision regulations, including standards for roads, drainage and lot layout². Inside the southeastern part of the county, Adirondack Park Agency land-use controls add another layer². In the Town of Canton, for example, minimum lot size, width, setbacks and height come from a district-by-district schedule, and lot size and frontage may be cut by 50 percent when a public or community water or sewer system serves the lot¹¹. Ask the municipal zoning or code office about setbacks, minimum lot and home size, accessory dwellings and allowed uses for the exact parcel.

In St. Lawrence County, obtain a permit to construct or modify an individual sewage system from the local code-enforcement office in the municipality where the property is located³. Systems with a flow of 1,000 gallons per day or more fall under New York State Department of Environmental Conservation jurisdiction and require SPDES permits and other approvals³. The county sanitary code applies throughout St. Lawrence County and supplements state law, and applicants for an individual system may have to show that no public or community sewer is available and accessible¹². The county Public Health Department does not issue permits or licenses, but its sanitarian provides sewage and water-quality guidance, investigates public-health nuisances and can conduct dye tests to assess seepage^13,14. Before buying land or commissioning a design, contact the town or village code office to learn its application, site-review and inspection requirements; we could not confirm one countywide septic-inspection procedure.

We could not confirm one countywide rule allowing long-term RV occupancy, temporary camping or tiny-home occupancy in St. Lawrence County. Those uses depend on the rules of the parcel's town, village or city, and enforcement varies by community². The Town of Canton shows how local the answer is: an owner may live in an RV while building a dwelling only in conjunction with a valid building permit, an owner-occupied lot may host an RV for guests for 30 days in a 12-month period, and on undeveloped lots in the R and RA districts up to two RVs may be used for up to 120 days in a 12-month period, one of them by the owner¹¹. Other towns may differ. A tiny home used as a dwelling must also follow the building-permit framework when its construction or placement must conform to the Uniform Code¹. Parcels inside the southeastern part of the county face an additional Adirondack Park Agency land-use layer¹⁰. Before buying or placing a unit, ask the local code office whether the zoning district permits the use, whether temporary occupancy during construction is allowed, and what septic permit is required³.

1. Identify the parcel's town, village or city, zoning district and Adirondack Park status; those determine which local and state land-use controls apply^2,15.
2. If land will be divided, ask whether municipal subdivision approval and County Planning Board referral are required before treating a proposed lot as buildable².
3. Ask the municipal code office for its building-permit application, locally adopted exceptions and fees; the application must cover the work location and scope, tax-map number, address, occupancy classification and applicable plans⁶.
4. Apply to that local code-enforcement office for the permit to construct or modify the individual sewage system³.
5. Keep covered work exposed and schedule the required construction inspections with the municipality¹.
6. Obtain a certificate of occupancy or compliance after inspection; it is required for permitted work and changes from one use or occupancy classification to another⁶.

Septic and soil: only about 1.1% of St. Lawrence County's soils rate better than "very limited" for a conventional septic drain field, so discuss the site with the municipal code-enforcement office before counting on a standard system^3,16. Floodplain: development in a Special Flood Hazard Area can require a local floodplain development permit even when the work is non-structural, so ask the municipal floodplain administrator to check the parcel and proposal¹⁷. Terrain: about 84.3% of the county's land sits at a 15% slope or gentler, while roughly 74.6% is wooded¹⁶. Agriculture: normal agricultural practices may be exempt from freshwater-wetlands permitting, but filling, clear-cutting and construction of non-agricultural structures are excluded, and other approvals may still apply¹⁸. Adirondack Park: check whether the parcel falls in the southeastern part of the county, where the state land-use plan applies². Taxes: the effective property tax rate is about 2.3%, with a median bill near $2,735 a year¹⁶.