Building Science: Different Insulation Materials Perform the Same When Properly Installed

An update to a Building Science Corp. study first released in 2013 confirms the original conclusion that proper installation and air-sealing is the determining factor in the thermal performance of test walls built to the same R-value using different types of insulation.

The multi-year test was conducted in collaboration with manufacturers and other industry partners. The initial goal was to develop a better metric for thermal performance by studying how thermal bridging, internal and external air movement, workmanship, and other factors affect the performance of modern insulating materials. The update adds test results for open-cell spray foam to those for fiberglass batts, cellulose, rigid foam sheathing, and closed-cell spray foam.

The full 150-page BSC report is summarized in this article from NAIMA (North American Insulation Manufacturers Association).