International Residential Code International Code Council Series 2021

The 2021 International Residential Code (IRC) establishes comprehensive requirements for construction, plumbing, mechanical, gas, and electrical systems in one- and two-family homes and townhouses up to three stories. This edition introduces several key updates to enhance safety and structural integrity.

• Retaining wall lines must be placed on a physical wall or between multiple walls.
• Two-family dwellings now require a 1-hour fire separation, regardless of whether a fire-resistance-rated wall is present.
• Emergency exits must have a minimum 36-inch-wide clear path to the public way.
• Storm shelters must follow a planned and designated design.
• Habitable attics are now limited to half the area of the floor below, and apartments must include sprinklers.
• Updated wind speed maps now align with IBC and ASCE 7 standards.
• Deck design now considers factors such as snow load, tributary area, and mast height, along with enhanced protection details.
• New requirements for deck guards have been introduced for improved safety.
• Component and cladding wind pressures in Table R301.2(2) have been revised to reflect updated wind speed standards and roof profiles.

The 2021 IRC remains an essential reference for builders, architects, and code officials, ensuring compliance with the latest residential construction and safety standards.