Relating to certain energy efficiency performance standards for residential construction.

HB 3314 establishes new energy efficiency standards for unvented attic and rafter assemblies in residential construction across Texas. It requires these assemblies to meet specific insulation levels (R-20 for climate zones 2-3, R-26 for zone 4), pass a blower door test (under 3.0 ACH50), include non-negative-pressure ventilation, and properly insulate exposed rafters in certain cases. The bill directly affects residential builders, local building jurisdictions, and new home construction projects. It creates an alternative compliance path for insulation standards under existing energy codes, effective September 1, 2025. The bill does not change the base energy code but provides an additional method to meet insulation requirements for specific attic/rafter designs.