How building permits work in Wisconsin
These rules apply across Wisconsin. Each local guide above covers what is specific to that city or county: its building department and contacts, permit types, fees and inspections.
Two state codes that apply everywhere
Wisconsin splits construction into two statewide instruments, and neither one is a city invention. One- and two-family homes run on the Wisconsin Uniform Dwelling Code (SPS 320 to 325), a code Wisconsin wrote for itself — the state never adopted the International Residential Code, so IRC chapter references from other states simply do not apply here. Everything that is a public building or a place of employment, including any residential building of three or more units, runs on the Wisconsin Commercial Building Code (SPS 361 to 366), which moved to the 2021 I-codes effective September 1, 2025; plans submitted on or after November 1, 2025 must comply with the 2021 editions. Under Wis. Stat. 101.65(1c) and 101.02(7r)(a), no city, village, town or county may enforce different technical standards — local ordinances must strictly conform to the state codes.
Commercial plan review and where the state reviews directly
Commercial plan review in Wisconsin is a two-step: under Wis. Stat. 101.12(3)(h) the plan approval comes first and the local permit cannot issue without it. Plan review is required for commercial buildings of 25,000 cubic feet or more. Some buildings need review at any size, including schools, high-hazard buildings, care and other institutional buildings, hotels and residential buildings of three or more units. DSPS does the review unless the municipality holds delegated authority for a building of that size. At 50,000 cubic feet plans must be prepared, signed and sealed by a Wisconsin-registered design professional, with a supervising professional retained for construction observation. Commercial plumbing plans go to review at 16 or more fixtures.
Contractor and trade credentials
Wisconsin has no state general contractor licence for commercial work — 2013 Wisconsin Act 20 ended state construction contractor registration on July 2, 2013. For one- and two-family work the state requires a Dwelling Contractor certification on the business and a Dwelling Contractor Qualifier on an individual, and under Wis. Stat. 101.65(1m) a municipality may not issue a building permit to a contractor who cannot produce them; owner-occupants are exempt. Electricians and plumbers are licensed statewide by DSPS. HVAC businesses must register with DSPS. There is no state HVAC licence, but DSPS offers a voluntary HVAC Qualifier certification. A city, village, town or county may require its own HVAC licence only if it already did so before November 1, 1993, and it cannot require one from a business that holds the state certification.