Modular Green Roof Blocks are intended to streamline the installation of sod roofs. “These are really simple, do a fantastic job of cooling the roof, and help keep heat loss down in the winter,” Rockhill says of the self-contained system. Fabricated from 22-gauge Galvalume, each 2-foot-by-2-foot block contains drought-resistant sedums planted in up to 12 inches of organic material. System weights range from 12 pounds to 51 pounds per square foot, depending on selected plant depth. Green Roof Blocks, 314.972.8010; www.greenroofblocks.com.