2021 International Residential Code International Code Council Series 1st Edition

This comprehensive code covers all construction, plumbing, mechanical, gas and electrical requirements for one- and two-family homes and townhouses up to three stories. The 2021 IRC includes many important changes, such as: Retaining wall lines must be placed on a physical wall or between multiple walls. Two family apartments are 1 hour apart, regardless of whether or not there is much line between the apartments. Emergency exits and exits require a 36-inch wide clear path to the public way. Storm shelters require a planned design. The habitable attic is limited to half of the floor below and the apartment needs sprinklers. Updated wind speed maps conform to IBC and ASCE 7 maps. The design of the deck now takes into account snow load, base branch area and mast height, as well as protection details. Added special requirements for deck guards. The component and sheath wind pressures in Table R301.2 (2) have been updated for the new dimensional wind speeds and shingle or gable roof profiles. The minimum stand size tables have been revised to more accurately reflect current practice. Wall setback requirements apply to exterior walls only. New appendices on cob construction and 3D printed construction are added. In balanced ventilation systems, there is a 30 percent reduction in airflow. Commercial gas cooking is prohibited. DWV systems water test head pressure increased to 10 feet. Air vacuum testing is now permitted for DWV systems in plastic piping.