Grant County, Wisconsin requires a building permit for a new one- or two-family home under Wisconsin's statewide Uniform Dwelling Code, and the county's Conservation, Sanitation & Zoning Department administers building, zoning, and septic review1. County comprehensive zoning applies in a named group of unincorporated towns, while rules outside that group must be confirmed parcel by parcel2. A sanitary permit must be issued before a zoning permit for a new home in a zoned town3.
At a glance
- Building permit
- Required for new 1- and 2-family homes under the statewide Uniform Dwelling Code, issued through the county's Conservation, Sanitation & Zoning Dept1
- Zoning
- County zoning ordinance applies in a list of named unincorporated towns; other towns and incorporated areas may zone themselves45
- Septic
- County-administered POWTS permits; $400 for most systems under 1,000 gpd, $500 for larger systems63
- Owner-builder exemption
- Yes: an owner who occupies or will occupy the home can pull the construction and erosion-control permits without a certified Dwelling Contractor7
- RV / camping on raw land
- Planned campgrounds in covered districts are seasonal and cap each trailer or campsite at 30 days; rules for one RV on an ordinary private parcel are unconfirmed8
- Minimum home size
- District-specific: 800 sq ft in Farmland Preservation/Agricultural districts, 1,200 sq ft in Residential R-1, down to 300 sq ft in R-3 and Conservancy-Forestry-Recreation9
- Minimum lot size
- District-specific: 1-3 acres in Agricultural districts, 4 acres in Conservancy-Forestry-Recreation, 4,000-6,000 sq ft in Residential R-1 through R-310
- Septic soil difficulty
- Only 2.8% of county soils are free of severe limits for a conventional drain field11
Who to call
Building permits
Grant County Conservation, Sanitation & Zoning Department
Uniform Dwelling Code building permits (new one- and two-family dwellings), issued after zoning and sanitary permit numbers are on file
150 W Alona Lane, Lancaster, WI 53813
Zoning
Grant County Conservation, Sanitation & Zoning Department
Zoning permits, shoreland and floodplain permit applications, and the Grant County Comprehensive Zoning Ordinance for the 18 towns under county zoning
150 W Alona Lane, Lancaster, WI 53813
Septic permits
Grant County Conservation, Sanitation & Zoning Department
Sanitary (POWTS/septic) permit applications, soil evaluation reports, and the 3-year POWTS maintenance program for Grant County
150 W Alona Lane, Lancaster, WI 53813
Contact details are copied from each office’s official page and were checked against it on September 28, 2026.
Do you need a building permit in Grant County, Wisconsin?
Yes. Wisconsin's statewide Uniform Dwelling Code requires a building permit for every new one- or two-family dwelling, and construction can't begin until plans are approved and the permit is issued and posted12. In Grant County, that permit is issued through the Conservation, Sanitation & Zoning Department, which also handles the county's zoning and septic review13. Inspections follow at each phase of construction: call before covering up any work, and the inspector has two business days after your request to inspect before you can proceed14. The dwelling's exterior must be finished within two years of permit issuance, and occupancy follows a final inspection that finds no major health or safety violations15. One sequencing rule matters for planning: a building permit can't be issued for a new dwelling using a septic system until a sanitary permit is already on file16.
Who is the Grant County building department, and how do you reach them?
The Grant County Conservation, Sanitation & Zoning Department handles building, zoning, and septic permits from one office at 150 W Alona Lane in Lancaster, phone (608) 723-608013. Office hours run Monday through Thursday, 7 a.m. to 4:30 p.m., and Friday 7 a.m. to 3:30 p.m.13. Because zoning, septic, and building permits are sequenced (sanitary before zoning before building), plan to work with this same department through the whole process rather than separate agencies17.
Does Grant County have zoning?
Yes, but the administering jurisdiction varies. Grant County lists Boscobel, Clifton, Ellenboro, Fennimore, Harrison, Hickory Grove, Jamestown, Liberty, Lima, Millville, Mt. Hope, Mt. Ida, Muscoda, Paris, Potosi, South Lancaster, Watterstown, and Wingville as the towns where its ordinances apply2. The county materials do not establish whether every omitted town is unzoned or instead follows town, municipal, or extraterritorial zoning, so confirm the parcel's jurisdiction with the zoning office218. Where county comprehensive zoning applies, the ordinance uses agricultural, residential, commercial, industrial, conservancy, and overlay districts19. Minimum dwelling and lot sizes vary by district: Agricultural A-1 calls for at least 3 acres and an 800-square-foot dwelling, while Residential R-1 calls for 6,000 square feet of lot area and a 1,200-square-foot dwelling910. Road-centerline setbacks also vary by road class20. Agricultural, accessory, and agriculture-related uses are allowed without a conditional-use permit in the Farmland Preservation district, subject to the district rules21.
How do septic permits work in Grant County?
Every private onsite wastewater treatment system (POWTS) in Grant County needs a permit before installation, issued by the Conservation, Sanitation & Zoning Department, and it must be installed by a Wisconsin-licensed Master Plumber or Master Restricted Sewer Plumber3. Permit fees run $400 for listed systems under 1,000 gallons per day and $500 for systems over that design flow3. In zoned towns, a sanitary permit must be issued before a zoning permit can be issued for a new single-family home3. Only 2.8% of county soils are rated without severe limitations for a conventional drain field, so make the soil evaluation an early contingency in a land purchase11. Non-plumbing sanitation systems and vaulted privies remain permit matters rather than automatic off-grid exceptions22. Grant County requires POWTS maintenance every three years after installation; the cycle can be satisfied by inspection or pumping by an authorized Wisconsin professional, followed by certification to the county23. The county must also inspect covered installations, replacements, modifications, reconnections, and removals before service unless an exemption applies24.
Can you live in an RV or tiny home on your land in Grant County?
Grant County's confirmed RV rule addresses planned trailer parks and campgrounds, not a single RV on an ordinary private parcel. In covered unincorporated areas, those planned facilities are limited to specified districts, operate seasonally, and cap each trailer or campsite at 30 days8. Planned campgrounds also need at least 10 acres and may not exceed 10 units per gross usable acre25. We could not confirm a county rule that answers whether a landowner may occupy one RV while building or live in it year-round, so ask the zoning office about the exact parcel and proposed duration before relying on an RV for housing18. We also could not confirm how Grant County classifies a tiny home; ask whether the proposed unit will be treated as a dwelling, manufactured home, trailer, or accessory structure18. A manufactured home installed as a primary dwelling has a state-code path, including installation standards for units produced on or after April 1, 2007, but local zoning and sanitary approvals still apply26.
Building a home in Grant County: the steps, in order
First, confirm whether your parcel sits in one of the towns under county zoning, and if so, identify its zoning district, since that sets your minimum lot size, dwelling size, and setbacks59. Second, if your home will use a septic system, get your soil evaluation and sanitary permit from the Conservation, Sanitation & Zoning Department first; a sanitary permit must be issued before a zoning permit for a new home273. Third, apply for your zoning permit, budgeting the fee at roughly $1 per $1,000 of estimated construction cost (minimum $100), rising to $2 per $1,000 for projects at or above $300,0001828. Fourth, apply for your Uniform Dwelling Code building permit, which needs your sanitary and zoning permit numbers on file before the building inspector will issue it1317. Fifth, if your land is landlocked, secure an access easement at least 66 feet wide unless one already existed before the town adopted comprehensive zoning17. Sixth, if your driveway will connect to a state highway, apply for a WisDOT connection permit before construction29. Finally, call for inspections at each construction phase before covering the work, and schedule your final inspection before occupying the home14.
What to check before you buy land in Grant County
Septic soils are the biggest constraint here: with only 2.8% of the county's land free of severe limitations for a conventional drain field, get a site evaluation before you commit to a parcel, and budget for a mound, at-grade, or other engineered system11. Confirm whether the parcel falls in one of the towns under county zoning, since that determines minimum lot size, dwelling size, and setbacks; land in a town not on that list may be unzoned or governed by its own town ordinance instead5. If the parcel is near water, check for shoreland zoning, which sets a 75-foot setback from the ordinary high-water mark and a 35-foot height limit within that zone3031. If any part of the parcel is mapped floodplain, a floodplain permit application is required before building there, and floodway construction is far more restricted than floodfringe3233. Grant County's terrain is mixed: 62.8% of land sits at 15% slope or less and 28.6% is wooded, so factor in clearing and grading costs on steeper or timbered parcels3435. Typical property tax runs about 1.4% effectively, with a median bill near $2,683 a year, against a typical home value around $229,957363738.
Watch-outs
- Grant County zoning only applies in the towns named on the county's zoning page; land in any other town may be unzoned or governed by that town's own ordinance, which changes minimum lot size, dwelling size, and setback answers entirely5.
- The confirmed 30-day RV limit applies to sites in planned campgrounds; we could not confirm the rule for one RV on an ordinary private parcel, so ask the zoning office before purchase or occupancy818.
- Tiny-home occupancy and accessory dwelling units aren't addressed by name in the county's zoning ordinance; confirm classification with the Conservation, Sanitation & Zoning Department before buying land for either18.
Sources
- Grant County Conservation, Sanitation & Zoning (2026 county census)
- Conservation, Sanitation, and Zoning – Grant County, quoted and re-checked
- Sanitary Permit Application Process, quoted and re-checked
- Conservation, Sanitation, and Zoning (2026 county census)
- Grant County Comprehensive Zoning Ordinance, amended May 16, 2023, quoted and re-checked
- Conservation, Sanitation, and Zoning – Grant County (2026 county census)
- Wisconsin DSPS - Building a Home in Wisconsin (UDC Guide) (2026 county census)
- Grant County Comprehensive Zoning Ordinance, quoted and re-checked
- Grant County Comprehensive Zoning Ordinance, quoted and re-checked
- Grant County Comprehensive Zoning Ordinance, quoted and re-checked
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Wisconsin’s Uniform Dwelling Code, quoted and re-checked
- Grant County Conservation, Sanitation & Zoning Department (gcinternetwebsite.co.grant.wi.gov)
- Wisconsin’s Uniform Dwelling Code, quoted and re-checked
- Wisconsin’s Uniform Dwelling Code, quoted and re-checked
- Wisconsin’s Uniform Dwelling Code (Wisconsin statewide rule), quoted and re-checked
- Zoning Permit Application Process, quoted and re-checked
- Grant County Conservation, Sanitation & Zoning Department (gcinternetwebsite.co.grant.wi.gov)
- Grant County Comprehensive Zoning Ordinance, amended May 16, 2023, quoted and re-checked
- Grant County Comprehensive Zoning Ordinance, quoted and re-checked
- Grant County Comprehensive Zoning Ordinance, quoted and re-checked
- Grant County Sanitary Fee Schedule, quoted and re-checked
- Three Year Maintenance Requirement, quoted and re-checked
- Grant County Code Chapter 225, Article V: Inspections, quoted and re-checked
- Grant County Comprehensive Zoning Ordinance, quoted and re-checked
- Wisconsin’s Uniform Dwelling Code (Wisconsin statewide rule), quoted and re-checked
- Grant County Conservation, Sanitation & Zoning Department (gcinternetwebsite.co.grant.wi.gov)
- Zoning Permit Application, quoted and re-checked
- State highway connection permits (driveways & more) (Wisconsin statewide rule), quoted and re-checked
- Wisconsin’s Shoreland Management Program (Wisconsin statewide rule), quoted and re-checked
- Minimum Shoreland Wetland Zoning Model Ordinance (Wisconsin statewide rule), quoted and re-checked
- Zoning Permit Application Process, quoted and re-checked
- Floodplain Development Basics (Wisconsin statewide rule), quoted and re-checked
- Share of land at 15% slope or less: Bolthole Index county data
- Wooded share of land: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- Typical home value (Zillow): Bolthole Index county data
Written September 28, 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.