“But what building codes become law in the U.S. depends on state and local governments, resulting in a confusing patchwork. A 2020 FEMA study found that 65 percent of counties, cities and towns across the country have not adopted the most recent building codes and that 30 percent of new construction is happening in places that either have no code or have not updated theirs in 20 years.”
Building Codes Save Money and Lives – Scientific American