Wisconsin Building Codes

Wisconsin has MANDATORY STATEWIDE Uniform Dwelling Code (UDC) for all one- and two-family dwellings since June 1, 1980. UDC is based on IRC with Wisconsin amendments (SPS 320-325). Municipalities CANNOT adopt more or less stringent codes - uniform statewide requirement. Enforced by state-certified local inspectors OR DSPS state inspectors (municipalities choose). Energy code based on IECC 2009 with WI amendments - older than most states. Commercial buildings follow IBC (SPS 361-366). DSPS Division of Industry Services administers code. 72 counties. Climate zones 6A (most of state) and 7 (northern tier). Cold climate construction requirements significant. Ice barrier requirements statewide. Frost depth 48-54+ inches depending on location.