Definition
The International Residential Code (IRC) is a model building code published by the International Code Council (ICC) that governs the design, construction, and maintenance of one- and two-family dwellings and townhomes. The IRC incorporates mechanical, electrical, plumbing, and energy requirements specific to residential applications, with updates issued every three years.
HVAC Provisions
The IRC establishes requirements for residential HVAC system design, including ductwork insulation (R-8 minimum for ducts in unconditioned spaces), equipment clearances, ventilation rates per ASHRAE 62.2, and combustion air supply for furnaces. It mandates mechanical inspections at rough-in and final completion stages to ensure code compliance.
Energy Code Integration
The IRC incorporates the International Energy Conservation Code (IECC) provisions, requiring SEER2 ratings of 15 or higher for air conditioners and minimum AFUE ratings of 90 percent for furnaces in many jurisdictions. Technicians must consult the specific edition adopted by local building departments, as adoption timelines vary significantly by state and municipality.