Building permits, zoning and land rules in Sanilac County, Michigan

At a glance

Building permit

Required before construction through the Sanilac County Construction and Land Use Department¹

Inspections

Periodic inspections are required for every county building permit²

Zoning

Approval comes from the applicable township, city or village and rules vary by municipality³

Septic and wells

Health Department septic review when bathrooms or bedrooms are added; permits before installation of covered new and replacement wells⁴⁵

RV living

Not confirmed countywide; ask the zoning administrator for the township, city or village covering the parcel³

Tiny home

Local zoning and construction approvals apply; wheels do not create automatic approval⁶

Owner-builder

State licensing allows an owner to build for the owner's own use and occupancy; county trade permits are limited to work the homeowner personally performs⁷⁸

Who to call

Contact details are copied from each office’s official page and were checked against it on October 12, 2026.

Do you need a building permit in Sanilac County, Michigan?

Yes. Unincorporated Sanilac County requires a building permit before construction and when a structure's use or occupancy changes¹. Ordinary repairs are exempt only when they do not include structural changes, changes to required exits, or work affecting public health or safety⁹. Michigan's construction-code system applies in Sanilac County, with residential requirements in the Michigan Residential Code¹⁰. Every building permit administered by the county requires periodic inspections². A new or altered building may not be used or occupied until the code official issues a Certificate of Occupancy¹¹. Inside Deckerville, the village ordinance also assigns building permits to the county, after village zoning compliance approval¹². Septic review remains with the Sanilac County Health Department when bathrooms or bedrooms are added¹³.

Who is the Sanilac County building department, and how do you reach it?

The Sanilac County Construction and Land Use Department accepts building, electrical, plumbing and mechanical permit applications at 60 West Sanilac, Courthouse Annex-Room 210, Sandusky, Michigan 48471¹⁴¹⁵. Applications are accepted from 8:00 a.m. to 4:30 p.m. on weekdays other than legal holidays, and inspections can be scheduled at (810)648-4664¹⁴¹⁵. A site sign and building-corner stakes are required before the site inspection and building-permit issuance¹⁵. The permit holder schedules inspections; most are completed within 3 business days, or up to 5 during busy periods¹⁵. County building permits do not replace zoning approval from the city, village or township covering the parcel; septic and well review for projects adding bathrooms or bedrooms remains with the Sanilac County Health Department³⁴¹⁶. The county may cancel a building permit if work has not begun and no inspection other than the site inspection occurs within 6 months, or if a started project stops for more than 6 months¹⁷.

Does Sanilac County have zoning?

For unincorporated Sanilac County, obtain zoning approval from the township zoning administrator before applying for the county building permit; local requirements vary³. Croswell, Lexington village and Deckerville have their own zoning rules¹⁸¹⁹²⁰. Septic review for projects adding bathrooms or bedrooms and permits for covered new or replacement wells remain with the Sanilac County Health Department¹³⁵. We could not confirm countywide setbacks, minimum lot or dwelling sizes, accessory-dwelling rules or RV occupancy standards; ask the zoning administrator covering the parcel. Lexington requires a zoning permit before construction, and Deckerville requires zoning compliance approval before the county building permit¹⁹¹².

How do septic and well permits work in Sanilac County?

The Sanilac County Health Department reviews existing sanitary facilities or septic-permit needs when a construction project includes bathrooms or adds bedrooms⁴. We could not confirm a universal septic-permit rule or septic-inspection timing; ask Environmental Health at (810) 648-4098 ext. 124 or eh@sanilachealth.com²¹. Covered new and replacement residential, hauled-water, irrigation, Type II and Type III wells require a Health Department permit before installation; submitting an application does not authorize drilling⁵. Installing a covered well before permit issuance triggers a fee of 3 times the basic permit fee⁵. About 12% of county soils are rated without severe limitations for a conventional drain field, so arrange a parcel-specific soil evaluation before fixing the house location²².

Can you live in an RV or tiny home on your land in Sanilac County?

We could not confirm a countywide rule allowing long-term RV living or temporary camping on private land in Sanilac County. Ask the city, village or township zoning administrator responsible for the parcel, because the county building-permit process requires that local zoning approval³. Michigan guidance does not treat a tiny house as a recreational unit merely because the house is built on wheels; the cited resort guidance requires local zoning, building, electrical and plumbing approvals, plus applicable well and septic permits⁶. That state guidance does not create a general right to occupy a tiny house or RV on a private rural parcel⁶. An owner may qualify for Michigan's residential-builder licensing exemption when building a residence for the owner's own use and occupancy⁷. For county mechanical, plumbing and electrical permits, the homeowner may apply only for work personally performed on the homeowner's own single-family dwelling; a hired contractor must obtain the permit⁸.

Building a home in Sanilac County: the steps, in order

1. Identify the city, village or township covering the parcel and obtain zoning approval from its zoning administrator³.

1. Ask the Sanilac County Health Department to review existing septic and well facilities or the need for septic and well permits when the home adds bathrooms or bedrooms⁴. Obtain a Health Department permit before installing a covered new or replacement well⁵.

1. Check floodplain status: construction, fill or alteration in a river, stream or drain floodplain with a drainage area of at least 2 square miles requires a state floodplain permit; new homes are prohibited in the floodway²³.

1. Obtain a driveway permit from the city, village, county or state authority controlling the road right-of-way if access is new or its use will change²⁴.

1. Apply to the Sanilac County Construction and Land Use Department for the building permit and any required electrical, plumbing or mechanical permits¹⁵.

1. Schedule periodic building inspections and obtain the Certificate of Occupancy before using the completed home²¹¹.

What should you check before buying land in Sanilac County?

Confirm the parcel's city, village or township and ask its zoning administrator for the allowed use, setbacks, dwelling standards and RV restrictions³. Arrange a soil evaluation before assuming a conventional drain field will work, because about 12% of county soils are rated without severe limitations for that use²². Check floodplain and floodway status before choosing a homesite: new residential construction is prohibited in the floodway²³. Verify who controls the frontage road, because that authority issues the driveway permit when access is new or its use changes²⁴. Recent parcel splits require advance county approval, and final subdivision plats undergo state compliance review before recording²⁵²⁶. The effective property-tax rate is about 0.9%, with a median annual bill of about $1,488²⁷²⁸.

Watch-outs

• Local zoning approval and county building permits are separate; the Sanilac County Health Department handles septic review when bathrooms or bedrooms are added and permits for covered new or replacement wells³¹³⁵.
• Only about 12% of Sanilac County soils are rated without severe limitations for a conventional septic drain field, so a parcel-specific soil evaluation belongs early in due diligence²².
• A state floodplain permit is required for construction, fill or alteration in a river, stream or drain floodplain with a drainage area of at least 2 square miles; new residential construction is prohibited in the floodway²³.
• New or changed driveway access needs a driveway permit from the city, village, county or state authority controlling the road right-of-way²⁴.

Sources

1. Building Permit Information, quoted and re-checked
2. sanilaccounty.gov, quoted and re-checked
3. sanilaccounty.gov, quoted and re-checked
4. Procedures and Instructions, quoted and re-checked
5. cms2.revize.com, quoted and re-checked
6. michigan.gov (Michigan statewide rule), quoted and re-checked
7. Frequently Asked Questions – Residential Builder (Michigan statewide rule), quoted and re-checked
8. sanilaccounty.gov, quoted and re-checked
9. Building Permit Information, quoted and re-checked
10. Building Permit Information, quoted and re-checked
11. Certificate of Occupancy Request (Michigan statewide rule), quoted and re-checked
12. Village of Deckerville: Code of Ordinances, Chapter 54, Sec. 54-101, Permits required (Sanilac County), quoted and re-checked
13. sanilaccounty.gov, quoted and re-checked
14. Sanilac County Construction and Land Use Department (sanilaccounty.gov)
15. sanilaccounty.gov, quoted and re-checked
16. sanilaccounty.gov, quoted and re-checked
17. sanilaccounty.gov, quoted and re-checked
18. Croswell: § 153.01 Adopted by Reference (Sanilac County), quoted and re-checked
19. Village of Lexington: Zoning & Development (Sanilac County), quoted and re-checked
20. Village of Deckerville: Code of Ordinances, Chapter 54, Sec. 54-210, Establishment of districts (Sanilac County), quoted and re-checked
21. Sanilac County Health Department — Environmental Health Division (sanilachealth.com)
22. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
23. FAQ: Floods and Floodplain Management, quoted and re-checked
24. sanilaccounty.gov, quoted and re-checked
25. sanilaccounty.gov, quoted and re-checked
26. Subdivisions (Michigan statewide rule), quoted and re-checked
27. Effective property tax rate: Bolthole Index county data
28. Median property tax bill: Bolthole Index county data

Written October 12, 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.