In a decision issued on October 13, 2015, the Minnesota Court of Appeals struck down the building code mandate requiring installation of fire sprinklers in larger homes promulgated by the Minnesota Department of Labor and Industry (DLI). The Sprinkler Mandate became effective on January 24, 2015 and required the installation of fire sprinklers in all new single family dwellings over 4,500 square feet in Minnesota. Although the phase-in for the Sprinkler Mandate started at 4,500 square feet, the Court of Appeals noted that the ultimate goal of the mandate was to require fire sprinkler systems in new homes of all sizes, not just larger homes. The Court of Appeals declared the Sprinkler Mandate invalid because it “violates substantive due process because it is arbitrary and not the result of a reasoned determination.”

In declaring the Sprinkler Mandate invalid, the Court of Appeals held that DLI failed to provide a “reasoned explanation” for how it determined that the 4,500 square foot threshold was appropriate. The Court noted that provisions of the building code, such as the Sprinkler Mandate, must be based on “the application of scientific principles, approved tests, and professional judgment.” However, DLI failed to provide any evidence or explanation supporting the Sprinkler Mandate’s 4,500 square foot threshold. The Court further determined that DLI violated rule making process because it failed to adequately analyze the cost of complying with the Sprinkler Mandate for small businesses and cities.  The Petitioner in the Court of Appeals, the Builder’s Association of the Twin Cities, also challenged DLI’s promulgation of amendments to the Energy Code. However, the Court determined that DLI acted within the scope of its authority and that amendments to the Energy Code was valid.