Cambridge | High-Tech Heating and Cooling This Old House : Season 27 Episode 6

Master carpenter Norm Abram and host Kevin O'Connor open the show at Cambridge Common — the city's oldest public open space and a center of rebel activity in the early years of the American Revolution. Back at the project house, Kevin lends Norm and general contractor Tom Silva a hand framing in the "not quite flat" roof above the library — it has a slight pitch to shed water. Plumbing and heating expert Richard Trethewey shows Kevin a new software program that allows him to design the HVAC system on a laptop and run heat loss scenarios for the house while changing variables like windows, insulation, and various kinds of ductwork and heating. Landscape contractor Roger Cook brings homeowner George Mabry to one of the largest stone yards on the East coast to begin selecting hardscape materials for the landscape.