1. Increased flexibility for envelope compliance (§ 150.1(c)).
2. Increased roof assembly requirements to include insulation installed either above or below roof deck (§ 150.1(c)1A).
3. Requirements for water-heating systems in single-family and multifamily buildings have been updated and more options have been added (§ 150.1(c)8).
4. High-performance attics and ducts in conditioned spaces have been added as an option for a space-conditioning distribution system (§ 150.1(c)9).
5. If a whole house fan (WHF) is required, it must comply with a total air flow of at least 1.5 CFM/ft2 and have 1 square foot of attic vent free area for each 750 CFM (§ 150.1(c)12).