This episode is once again set in Lexington, Mass., at the "Big Dig" house. Host Kevin O'Connor goes to Kyle, Texas, to see how a 1920s-era cement plant has become a one-of-kind home in a great case of adaptive reuse. In Bangor, Maine, licensed contractor and host Amy Matthews visits the Hallowell factory to investigate how a heat pump can squeeze heat from the minus-30-degree air of a northern winter. Amy takes a look at zinc shingles and panels, which have become the latest trend in roof and wall cladding. Near Los Angeles, Calif., Amy checks out a brand-new product - barrel roof tiles with built-in thin-film photovoltaics.