Which of the following best describes an environmental performance benefit of cellulose insulation when installed properly?

• A. Recycled content
• B. Lower embodied energy than some foams
• C. Good airtightness when installed correctly
• D. Uses less energy to produce than some foams

Answer: (C)

Good airtightness achieved through proper installation is the environmental performance benefit most directly connected to cellulose insulation. When installed correctly, the material fills cavities well and minimizes air leaks through the building envelope. That tighter envelope reduces heating and cooling energy use, lowering operating energy and related emissions over the building’s life. The key is avoiding gaps and compression, which would compromise the air barrier and the energy savings.

Other aspects, like recycled content or lower embodied energy in production compared with some foams, describe environmental attributes but aren’t driven by how the installation is performed. They’re important, but the immediate environmental benefit tied to proper installation is the improved airtightness and the resulting reduction in energy use.