What code should be used if the IRC is not referenced for energy efficiency?

The International Energy Conservation Code (IECC) is the appropriate code to refer to for energy efficiency when the International Residential Code (IRC) does not provide specific references. The IECC is designed to set minimum energy efficiency standards for residential and commercial buildings, focusing on conserving energy and enhancing the performance of buildings regarding energy consumption.

When the IRC is not applied or is not specific about energy efficiency requirements, the IECC steps in as the alternative guideline, ensuring that energy conservation practices are still met to promote sustainability and reduce energy costs for building occupants. This makes the IECC a critical resource for inspectors assessing compliance with energy efficiency standards in residential settings.

The other codes mentioned either do not specifically address energy efficiency or pertain to different aspects of building safety and construction regulations, thus falling outside the scope of energy-related inspections in residential buildings.