2024 International Residential Code International Code Council Series1st Edition

The 2024 International Residential Code (IRC) is a comprehensive standard encompassing all building, plumbing, mechanical, fuel gas, and electrical requirements for one- and two-family dwellings and townhouses up to three stories in height.

This edition introduces several significant updates to enhance safety, consistency, and modern building practices:

• Wall Bracing and Separation: Braced wall lines must now align with physical walls or be placed between multiple walls. Two-family dwellings require a 1-hour fire-resistance-rated separation—regardless of whether a lot line exists between units.

• Egress and Safety: Emergency escape and rescue openings must include a clear 36-inch-wide path to a public way. An engineered design is now required for all storm shelters.

• Attics and Sprinkler Systems: Habitable attics are limited to half the area of the floor below, and sprinkler systems are required in new dwellings.

• Wind and Structural Design: Wind speed maps have been updated to match those in the IBC and ASCE 7. Table R301.2(2) now reflects updated component and cladding wind pressures, including considerations for hip and gable roofs.

• Deck Design Enhancements: Decks must now account for snow load, tributary area for footings, post height, and specific guardrail requirements.

• Footing and Wall Standards: Revised minimum footing size tables provide greater accuracy. Cripple wall requirements are now limited to exterior cripple walls only.

• New Construction Methods: Appendices for cob construction and 3D-printed construction are newly added.

• Ventilation and Mechanical Updates: A 30% reduction in airflow is allowed for balanced ventilation systems. Commercial gas cooking appliances are now prohibited in residential settings.

• Plumbing Changes: The required head pressure for DWV (drain, waste, vent) system water tests has increased to 10 feet. Air vacuum testing is permitted for plastic DWV piping.

• Fire Protection and Sprinklers: Section P2904 regarding residential sprinkler systems has been expanded to better align with NFPA 13D.

• Electrical Safety Requirements: An emergency service disconnect must be installed in a readily accessible outdoor location. A surge protective device (SPD) is now required at the main service panel.

• Kitchen Receptacles: The number of receptacle outlets for peninsular and island countertops is now based on the total surface area of the countertop.

These updates reflect the latest industry practices and technologies, aiming to improve safety, energy efficiency, and usability in modern residential construction.