2027 International Residential Code®

Construction code for one- and two-family dwellings and townhomes, 3 stories or less in height, each with a separate means of egress. Provides minimum requirements for low-rise residential construction and related accessory structures, balancing affordability with life safety, property protection, health, welfare, energy conservation, and responder safety. Mechanical, fuel gas and plumbing are also included.

This comprehensive code comprises all building, plumbing, mechanical, fuel gas, energy conservation and electrical requirements for one- and two-family dwellings and townhouses up to three stories. The 2027 IRC® contains many important changes:

• Clarification for determining design flood elevations including where floodways are not designated in riverine flood hazard areas.
• ASCE 24 definitions for flood hazards are added including; 500-year Floodplain, Base Flood, Base Flood Elevation, Design Flood Elevation, Flood Hazard Area.
• Fire-resistance requirements for exterior walls are clarified with tables added for prescriptive 1-hr and 2-hr walls.
• Provisions are added for corrosion resistance in saltwater environments.
• Provisions are added for occupiable roofs.
• Requirements for electric vehicle charging systems are added.
• Accessibility requirements for townhouses where some units are single story are clarified.
• New tables are provided to address dropped headers.
• Reroofing in hurricane-prone regions may require supplemental attachment of the roof deck.
• Additional (energy) credit requirement is increased from 10 to 15 and the list of HVAC performance options is expanded along with other additional equipment and appliance provisions.
• An Energy Certificate is required for additions.
• New provisions for Germicidal UV Irradiation Systems are added.
• Water supply system test using gas is expanded to include PE-RT piping.
• Receptacle outlets are prohibited in specific locations when below countertops or work surfaces.