Like many architects, we have begun to pay much closer attention to the embodied carbon associated with the materials we are specifying. All other things being equal, selecting a material with a lower global warming potential (GWP) is preferable. However, at this early stage, not many of us have a strong intuitive sense of how meaningful various GWP values might be ? e.g. is 223 kgCO2e/m2 of insulation good or bad" 

We performed a study to compare the embodied carbon values for nine commonly used types of insulation with the goal of presenting the results in a relatable way. The insulation products considered include two brands of XPS, two brands of next-gen XPS, Polyiso, Rockwool, Neopor GPS, fibreglass batts, and blown cellulose.
Insulation is somewhat unique among building materials in that one of the primary reasons it is incorporated in buildings ? to reduced energy flow through the building envelope ? has a significant direct impact on the operational emissions produced by the building.

In our study, we contrive a familiar scenario: a homeowner with an uninsulated bearing masonry house wishes to add insulation to reduce their energy costs and increase comfort in the home. Specifically, they would like to increase the effective R-value of their home from its current performance of R4IMP to a value more in line with the current building code, R24IMP. We calculate the embodied carbon associated with the amount of each type of insulation required to achiev...