2021 International Residential Code International Code Council Series Isbn 9781609839574

The 2021 International Residential Code (IRC) introduces several key updates to enhance safety, design flexibility, and compliance. Among the changes, braced wall lines must now be placed on or between physical walls, and two-family dwellings require a one-hour rated separation between units, even without a lot line. New provisions include clearer guidelines for emergency escape and rescue openings, which must have a 36-inch-wide path to a public way, and mandatory engineered designs for storm shelters. Additionally, the code limits the size of habitable attics to half the area of the story below and mandates sprinkler systems in all dwellings. Wind Speed maps have been updated to align with the latest IBC and ASCE 7 standards, and deck design now considers snow load, post height, and guardrail specifications. Further revisions involve updated wind pressures, minimum footing sizes, and cripple wall requirements for exterior walls. The 2021 IRC also introduces appendices for cob and 3D-printed construction. Changes in mechanical and plumbing systems include a 30% reduction in airflow for balanced ventilation systems, a ban on commercial gas cooking appliances, and stricter water test pressure requirements for DWV systems.