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

At a glance

Building permit

Required; the enforcing office depends on your township or city¹⁶³

Zoning

Check the parcel's township or city; a complete countywide determination was not confirmed⁴

Septic permit

Required before installation; handled by Washtenaw County Environmental Health²⁵

Owner-builder exemption

Appears available for an owner building a home for personal use; confirm affidavit eligibility⁷

Certificate of occupancy

Required before you use or occupy new or altered construction⁸

Tiny house on wheels

Local land-use approval is unconfirmed; ask the township or city before buying⁹

Median property tax bill

$5,505 a year, at an effective rate of about 1.6%¹⁰¹¹

Population density

About 518 people per square mile countywide¹²

Who to call

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 Washtenaw County, Michigan?

Yes. Washtenaw County, Michigan requires a building permit before construction or remodeling begins¹. Residential work follows the Michigan Residential Code, while the current Michigan Building Code took effect April 9, 2025⁶. The enforcing agency depends on the parcel's jurisdiction, so the county is not automatically the permit office for every township or city³. Freedom, Bridgewater and Manchester Townships and the Village of Manchester, for example, use the Western Washtenaw Construction Authority¹³. A new or altered building subject to Michigan's construction code cannot be occupied until the code official issues a certificate of occupancy⁸. An owner building a residence for personal use appears eligible to act as general contractor through a homeowner affidavit, but confirm the licensing exception with the enforcing agency before relying on it⁷.

Who issues building permits in Washtenaw County, and how do you reach them?

Confirm the enforcing agency for the parcel before applying, because building-code jurisdiction varies across Washtenaw County³. In Freedom Township, the Western Washtenaw Construction Authority issues building permits for Freedom, Bridgewater and Manchester Townships and the Village of Manchester¹³. The authority is at 912 City Road, P.O. Box 556, Manchester, Michigan 48158, and its phone number is 734-428-7001¹³. Freedom Township applicants must first obtain a zoning compliance certificate from the township; its Zoning Administrator is at 11508 Pleasant Lake Road, Manchester, MI 48158, phone 734-428-7545 ext. 4¹⁴. For land elsewhere in Washtenaw County, ask the parcel's township or city which agency receives the building-permit application; county enforcement applies only where the jurisdiction assignment designates it³.

Does Washtenaw County have zoning?

Zoning is administered at the township or municipal level in Washtenaw County, and the county planning department keeps township ordinances and maps on file⁴. Michigan law allows counties, townships, cities and villages to establish zoning districts, but the statewide framework does not identify the district or rules for a particular parcel¹⁵. A complete countywide zoning determination was not confirmed, so do not infer that land is unrestricted from a county-level search. Ask the parcel's township or city about minimum lot size, setbacks, building height, lot coverage, accessory dwellings and agricultural uses before designing the project. Freedom Township, for example, requires a zoning compliance certificate before an applicant seeks a building permit from the Western Washtenaw Construction Authority¹⁴.

How do septic permits work in Washtenaw County?

Washtenaw County Environmental Health handles onsite sewage permitting, and a sewage permit is required before a system may be installed⁵². A soil evaluation is required before building a home that will not use a municipal or centralized sewage-treatment facility². Installations and repairs must be performed by people certified by the county Environmental Health Division⁵. The office is at 705 North Zeeb Road, Ann Arbor, Michigan 48103, phone 734-222-3800¹⁶. Michigan requires household sanitary sewage to go to a municipal sewer or an onsite septic system¹⁷. Only about 12 percent of Washtenaw County soils lack severe limits for a conventional drain field, so make the soil evaluation an early purchase contingency rather than assuming a standard system will fit¹⁸. We could not confirm the county's inspection stages or permit fees; ask Environmental Health before scheduling work.

Can you live in an RV or place a tiny home on your land in Washtenaw County?

We could not confirm a countywide rule allowing RV occupancy, temporary camping or tiny-home occupancy on private land in Washtenaw County. Ask the parcel's township or city zoning office before buying land or moving a unit onto it, because local zoning districts and regulations control parcel-level land use⁴¹⁵. Michigan guidance for tiny houses proposed as resort cabins says a tiny house is not treated as a recreational unit merely because it is on wheels, and that local zoning, building, electrical, plumbing and health approvals apply in that setting⁹. That resort guidance does not establish permission to occupy a tiny house or RV on an ordinary private parcel. If the site will use septic, Washtenaw County requires the sewage permit before installation and requires a soil evaluation for a home without municipal or centralized sewer service².

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

1. Identify the parcel's township or city and confirm which agency enforces the building code there³.
2. Ask that local zoning office which approvals, setbacks and dimensional rules apply; Freedom Township, for example, requires a zoning compliance certificate before the building-permit application¹⁴.
3. If the home will not use municipal or centralized sewer service, obtain the required soil evaluation and apply to Washtenaw County Environmental Health for the sewage permit before installation².
4. Submit the building-permit application to the enforcing agency before construction begins¹³.
5. Ask the road authority whether the proposed entrance needs approval; a county-road driveway in Freedom Township requires a Washtenaw County Road Commission permit¹⁹.
6. Use installers certified by Washtenaw County Environmental Health for septic installation or repair⁵.
7. Complete the required permit inspections and request a certificate of occupancy before using a new or altered building covered by Michigan's construction code⁸.

What to check before you buy land in Washtenaw County, Michigan

Before making an offer, identify the parcel's township or city and obtain its zoning map and dimensional rules; a complete countywide answer for minimum lot size, setbacks and permitted uses was not confirmed⁴¹⁵. Make septic feasibility a contingency when municipal or centralized sewer service is unavailable, because a county soil evaluation is required and only about 12 percent of Washtenaw County soils lack severe limits for a conventional drain field²¹⁸. Confirm the building-code enforcing agency because jurisdiction changes by municipality³. Ask the applicable road authority about driveway access; the verified county-road permit statement applies specifically to Freedom Township¹⁹. The median property-tax bill is $5,505 a year at an effective rate of about 1.6 percent, useful context when comparing raw-land carrying costs¹⁰¹¹. We could not confirm countywide private-well, floodplain-development or land-division requirements, so ask the township or city and the relevant county office before closing.

Watch-outs

• Do not assume one building department covers all of Washtenaw County: building-code jurisdiction depends on the township or city³.
• We could not confirm a countywide right to occupy an RV or tiny home on private land; ask the parcel's township or city zoning office before buying or moving a unit onto the site⁴.
• A septic permit is required before installation, and installation or repair must be done by someone certified by Washtenaw County Environmental Health²⁵.

Sources

1. Washtenaw County Building & Construction (2026 county census)
2. Installing a Septic System in Washtenaw County, quoted and re-checked
3. Building Permit Information (Michigan statewide rule), quoted and re-checked
4. Washtenaw County Ordinances (2026 county census)
5. Installing a Septic System in Washtenaw County, quoted and re-checked
6. Code Books, quoted and re-checked
7. Michigan LARA Building Permit Information (2026 county census)
8. Certificate of Occupancy Request (Michigan statewide rule), quoted and re-checked
9. 2022 ARVC - General (Michigan statewide rule), quoted and re-checked
10. Median property tax bill: Bolthole Index county data
11. Effective property tax rate: Bolthole Index county data
12. Population density: Bolthole Index county data
13. Western Washtenaw Construction Authority (freedomtownshipmi.org)
14. Freedom Township Zoning Administrator (freedomtownshipmi.org)
15. Michigan Zoning Enabling Act (Michigan statewide rule), quoted and re-checked
16. Washtenaw County Environmental Health Department (freedomtownshipmi.org)
17. Disposal of residential wastewater such as swimming pool water (Michigan statewide rule), quoted and re-checked
18. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
19. Washtenaw County Road Commission (freedomtownshipmi.org)

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.