Economical approach to IRC2021 compliant wall insulation – GreenBuildingAdvisor

See the attachment – Here are two (of several) ways to meet the IRC2021 and IRC2024 wall insulation requirements (zones 4-8).

1. Mooney Wall

2. 2×8 framing

3. A third closely related but not illustrated would be a double wall of 2×4 studs with the same total thickness as the 2×8 option.  We can consider that as well.

Questions:

1. Are you seeing any of these 3 become commonplace in your area?

2. Which do you deem would be most economical to build? 2×8 seems like least labor cost but highest material cost. Mooney seems like least material cost and less labor than double wall.

3. What are big developers like Lennar and KBHome doing to meet wall insulation requirements?