Energy · IECC 2021 §R402.2.5 / Table R402.1.3 / Table R402.1.2
Mass Wall Definition and Insulation Placement
What counts as a mass wall and how the insulation side changes the answer: first and second R-values by climate zone, mass wall U-factors, and the lower U limits when more than half the insulation is inside.. Referenced to IECC 2021 §R402.2.5 / Table R402.1.3 / Table R402.1.2.
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