Minarc specs concrete floors for their durability and versatility. Ingjaldsdóttir and Thorsteinsson also use the surface to regulate temperature, designing many of their houses (including the one above) so the sun slowly heats the mass of the floor, which stays cool by day but radiates warmth at night. Portland Cement Association, 847.966.6200; www.cement.org.
other favorites Building Materials Reuse Association: salvaged building products, www.bmra.org
FlexibleLove: recycled paper and wood furniture, www.galleryskart.com
tryggvi thorsteinsson, assoc. aia, and erla dögg ingjaldsdóttir, assoc. aia
santa monica, calif.