Barndominiums in Michigan

Outside city limits: Yes. A new home needs a building permit before construction starts. The owner or builder files a written application with plans and a site plan with the local enforcing agency (township, county or city) or, where none has taken over enforcement, the state. The exemption for farm buildings covers only buildings incidental to agricultural use that are not used in retail trade, so it does not apply to a dwelling. Some county health departments also require septic and well approval before they will issue a building permit.

Michigan has a single statewide construction code, set under the Stille-DeRossett-Hale Single State Construction Code Act (1972 PA 230), and it applies throughout the state, including rural areas. The state enforces it by default, but a city, village, township or county can take over enforcement by ordinance, and can hand it back to the state with 12 months' notice. In a rural area, the permit office is therefore the township or county if it has taken over enforcement, and the state Bureau of Construction Codes (LARA) if it has not. The code is built on the international residential, building, mechanical, plumbing, energy and existing-building codes plus the National Electrical Code, with Michigan amendments, and residential rules are updated every 3 to 6 years.

• The code and the Act apply throughout Michigan. Local governments that enforce a different model code must say whether they will enforce the state code; if they do not, the state takes over unless the county has filed its own notice. A locality that adopts the code after its effective date needs approval from the construction code commission, which must decide within 90 days. source
• The state director administers and enforces the code by default. A city, village, township or county may assume enforcement by ordinance and must name an enforcing agency registered under the Skilled Trades Regulation Act. Localities may enforce jointly. A locality that withdraws returns enforcement to the state after 12 months. source
• Before constructing a building, the owner or builder must apply to the enforcing agency for a building permit, with fee, specifications, scaled plans and a site plan. Ordinary repairs and buildings incidental to agricultural use that are not used in a retail business are exempt. source
• The state construction code incorporates the international residential, building, mechanical, plumbing, existing building and energy conservation codes and the National Electrical Code, with Michigan amendments. Residential rules are reviewed every 3 to 6 years and commercial rules at least every 3 years. source

Michigan has no uniform statewide septic code. Local county or district health departments issue septic construction permits for typical homes, and the state environmental agency (EGLE) handles larger flows; Lenawee County, for example, handles systems up to 10,000 gallons per day. Before issuing a permit, health departments generally evaluate the site, looking at soil permeability, seasonal high water table, available land area and distance from water supplies. Fees, forms and procedures differ by county, and some departments cover several counties. Proposed legislation would create a statewide septic code, but it has not become law.

• Lenawee County requires a construction permit before a sewage disposal system is installed. The permit comes from EGLE or the county health department depending on the type and volume of wastewater. The county evaluates soil permeability, seasonal high water table, land area and isolation from water supplies, and has a separate procedure for parcels under 1 acre. source
• A December 2024 Senate Fiscal Agency analysis reports that Michigan lacks uniform onsite wastewater standards, that local health departments administer the conventional-system rules under Part 127 of the Public Health Code, and that local governments issue installation permits. source
• Senate Bill 299 of 2023, which would have created a statewide onsite wastewater part of the Public Health Code, passed the Senate on 12/12/2024 and was referred to a House committee on 12/13/2024; no later action is recorded and it was not enacted. source
• Senate Bill 771, introduced 1/28/2026, would create a statewide septic part and require EGLE to write a statewide sewage code within three years of the act taking effect. It is an introduced bill, not law. source
• An available public sewer is one that passes within 200 feet of a building that produces sewage, and state law declares connection to an available public sewer to be in the public interest. This matters for rural lots near a sewer line. source
• In Manistee County, District Health Department No. 10 is the office for well and septic permits in most communities, an example of one department serving several counties. source

The U.S. Department of Energy lists the 2015 International Energy Conservation Code, with Michigan amendments, as the residential energy code in effect, effective 02/08/2016 and mandatory statewide. The Department of Energy's page shows no newer residential edition adopted.

• DOE state profile: residential code is the 2015 IECC with Michigan amendments, effective 02/08/2016, enforced statewide. The commercial code is the 2021 IECC (with ASHRAE 90.1-2019), effective 04/22/2025. source

Property tax

Qualified agricultural property is exempt from the school operating tax. To qualify, more than 50% of the parcel's acreage must be in agricultural use, and the property and buildings must be unoccupied and devoted to agriculture. A house counts only if it is occupied by someone employed in or actively involved in the farm use who has not claimed a principal residence exemption elsewhere. Commercial or industrial use does not qualify, so check with the local assessor how a new home on farm-classified land would be treated. A home you live in can instead get the Principal Residence Exemption, which exempts it from the local school operating tax. To claim it, file an affidavit with the local tax collecting unit on the Treasury form by June 1 for the summer levy or November 1 for the winter levy, and rescind it within 90 days if the home stops being your principal residence.

• Qualified agricultural property needs more than 50% of the parcel's acreage in agricultural use. A dwelling qualifies only as a related building, meaning it is occupied by someone employed in or actively involved in the agricultural use who has not claimed a principal residence exemption elsewhere. source
• A principal residence is exempt from the local school operating tax. The owner files an affidavit with the local tax collecting unit; deadlines are June 1 (summer levy) and November 1 (winter levy). Late claims are allowed for the current and three preceding years, each owner gets one exemption, and the owner must rescind within 90 days when the home stops being a principal residence. source