NY S05940

Amends executive law section 378 to allow unvented attics and enclosed rafter assemblies to be sealed with air-impermeable insulation (R-30 minimum, U-Factor maximum 0.038) as a code-compliant option for building construction

Requires homes using this insulation method to achieve a blower door test result of less than 2.5 ACH50 (air changes per hour at 50 pascals pressure)

Mandates installation of a positive, balanced, or hybrid whole-house mechanical ventilation system that does not rely solely on negative pressure

Requires all indoor heating, cooling, and ventilation equipment, including ductwork, to be located inside the building thermal envelope

Takes effect 180 days after becoming law, with the state fire prevention and building code council required to immediately promulgate implementing standards