International Energy Conservation Code

Section 402.1.1   Insulation and fenestration  criteria

The building thermal  envelope will meet the requirements of Table 402.1.1 based on the climate zone specified in Chapter 3 of the IECC.

Code Interpretation

This code implies that there are prescribed thermal R-values for residential ceilings. The R-value is based on the climate zones identified within the International Energy Conservation Code.

Climate Zone  Ceiling R-Value

• 1          30
• 2          30
• 3          30
• 4          38
• 5          38
• 6          49
• 7          49
• 8          49

 Note: 402.1.2 R-value computation indicates that R-value shall be based solely on insulating material and shall not include other building materials or air films.