By Irene Butler
The adoption of new building codes in Wisconsin had been in flux in Wisconsin. However, Wisconsin has transitioned to the 2021 International Code Council (ICC) model codes on October 1, 2025.
A brief history of this code-adoption flux is included herein. Wisconsin was set to retire its 2015 commercial building codes and transition to the 2021 International Code Council (ICC) model codes. Under the administrative rules, all commercial building plans submitted to the Department of Safety and Professional Services (DSPS) had to comply with the new codes by October 1, 2025. These requirements apply to commercial buildings, including multifamily and residential structures. The adoption incorporates the 2021 International Building Code, the 2021 International Energy Conservation Code, and other model codes, by updated safety, energy-efficiency, and performance standards. The legislature attempted to block the administrative rules to make these code changes. But, the state Supreme Court ruled that the Legislature cannot indefinitely block administrative rules.
However, pushback continued. In September, Senate Bill 450 was introduced to delay the implementation date to April 1, 2026. The legislation received support from major real estate and construction industry groups, including the Apartment Association of South Central Wisconsin, Associated Builders and Contractors of Wisconsin, and NAIOP Wisconsin.
Although the bill passed both chambers, Governor Tony Evers (D) ultimately vetoed the legislation. The 2021 code update introduces more rigorous standards for building enclosure performance, sustainability, and energy efficiency. These changes bring Wisconsin in line with national trends that prioritize greener construction practices and lower long-term operating costs.
