Session 3: The Energy Advantage of ICF

Once upon a time, an R value was an R value. It was a measure of the thermal resistance of an insulating material or layer. When our walls were effective R 2 (2 x 4 with no insulation), or R 4 (when we filled those walls with sawdust and other interesting materials) or R 8 (with 2 x 4 batt) and then R 16 (2 x 6 walls with batt), the effective insulating value of the entire wall assembly was reasonably close to the value of the insulation that we used to improve that performance. This session explains how energy performance must now be evaluated as we move towards Net Zero homes by 2032, and how the actual thermal performance of ICF has always been significantly greater than the nominal R value of the polystyrene ICF forms themselves. Thermal massing, effective insulation values and many other mysteries will be clearly and simply explained. This will also provide the tools to understand why ICF has always delivered much higher thermal performance and high lateral load resistance but is only now getting the credit it deserves under the recent evolution of building codes in Canada.