Back in Barrington, Andy shows Norm the electric floor warming system he's using in the master bathroom. It gets mudded directly into the tile bed, which holds 12" x 12" porcelain tile that will also make up the front apron of the tub. In the side alley, plumbing and heating expert Richard Trethewey shows Kevin where he's tucked away the A/C condensers, and then, inside, shows him the ERV that is in the attic, and why it is possibly the most important piece of mechanical equipment in the house.