This episode is set at the Cleantech House in Beverly, Mass., a showcase of the latest in energy-saving design. Host Kevin O'Connor visits Blu-Homes, a Waltham, Mass., company that's trying to deliver on the promise of prefab housing by making buildings that fold up for shipping. Licensed contractor and host Amy Matthews goes to Las Vegas, Nev., to see a Department of Energy project that brings a 1960s home up to net-zero modern standards. Kevin explains energy-recovery ventilators and Amy discovers Accoya, a treated wood that lasts for 50 years without needing paint or stain. Kevin goes to the NuCedar factory in Chicopee, Mass., to sees how PVC siding is made. At the International Builders' Show in Las Vegas, Amy is off to see a P-trap sink drain that never clogs.