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.

In order to improve safety, consistency, and current building practices, this edition includes a number of significant updates:

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:
New homes must have sprinkler systems, and livable attics can only cover half of the floor below.

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.

Wall and Footing Standards:
The new minimum footing size tables are more accurate.
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.
In residential settings, commercial gas cooking appliances are now prohibited.

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:
To better align with NFPA 13D, Section P2904 has been expanded to include residential sprinkler systems.

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.