Architects seeking to lower the environmental footprint of commercial buildings can start at the top—on the roof. New environmental regulations adopted by Canada and several U.S. states aim to eliminate the use of high-global warming potential blowing agents in several types of closed-cell foam insulations, including extruded polystyrene insulation (XPS).

Aiming to curb the use of hydrofluorocarbon (HFC), and specifically the use of HFC-134a, the regulation applies to all of Canada and a growing number of U.S. states including California, Colorado, Delaware, Maryland, Massachusetts, New Jersey, New York, Vermont, and Washington. Even more states have proposed similar legislation or are set to implement comparable environmentally focused regulations in the coming months. At the national level, the U.S. has also pledged to ratify the Kigali Amendment to the Montreal Protocol, an agreement that calls for a reduction in HFC use. Recognizing the challenge of meeting increasingly stringent environmental regulations, several XPS manufacturers have introduced XPS products using low-GWP blowing agents.

Figure 1 – Regulatory changes regarding insulation manufacturing and blowing agent selection are being adopted piecemeal across the U.S., with more states moving toward reducing the GWP levels used in XPS production.
Figure 1 – Regulatory changes regarding insulation manufacturing and blowing agent selection are being adopted piecemeal across the U.S., with more states moving toward reducing the GWP levels used in XPS production.

Shifting regulations bring new questions

This shift in the regulatory landscape surfaces an important question for architects designing sustainable, high-performing buildings: Is it possible to comply with new regulations without compromising the material performance that has made XPS insulation a trusted building material for decades? XPS has long been a go-to insulation for vegetative roof assemblies, and it is favored for a number of performance attributes including compressive strength, high water resistance, and impressive thermal properties. The performance of XPS insulation is trusted in innovative roofs across the nation—from the massive U.S. Coast Guard Headquarters in Washington, D.C., to Dickies Arena in Fort Worth, Texas. Installed in commercial rooftops and plaza decks, XPS insulation delivers properties that underlie highly functional rooftops, supporting massive green areas, vehicular traffic, and public event spaces. Therefore, an insulation’s compressive strength is essential.

Significant research informed the development of Owens Corning FOAMULAR NGX, an XPS insulation that eliminates HFC-134a and delivers an 80% reduction in embodied carbon. While the insulation’s GWP is drastically reduced, this material innovation maintains critical performance attributes including moisture management, thermal properties, and compressive strength.

Evaluating the difference

One way to evaluate the difference this new insulation can have on the environment is to consider its performance in the context of a typical application. Replacing a traditional extruded polystyrene board with a next-generation offering can result in a significant reduction in carbon dioxide equivalents. Every 10 boards of FOAMULAR NGX installed reduces carbon dioxide equivalent emissions comparable to removing one car from the road for a year.

As more stringent environmental regulations are adopted, innovations in material science can support sustainability without compromising performance.