Check out our new Energy Code Smart Tip for below-grade insulation!

What insulation is required for below-grade walls? On the one hand, these walls require less insulation compared to above-grade walls because of the relatively moderate temperature of the earth. However, care must be taken to ensure an adequate and continuous thermal envelope where the foundation meets the wall.

This document summarizes the below-grade wall requirements for Illinois and provides guidance for designing successful installations.

Read the Energy Smart Tip