Spray foam gets the firm's vote as an effective insulation. “We're convinced by the performance,” Harpman explains. A favorite is BioBased, which comes as an open-cell product that uses soybeans in its formulation or as a water-blown, closed-cell product. R-values range from 20 to 28. BioBased Technologies, 800.803.5189; www.biobased.net.
Specht Harpmanlouise harpman, assoc. aia, and scott specht, aia
austin, texas, and new york