This Old House - Season 47 Episode 15 -

Richard Trethewey meets with the HVAC subs who are here to re-duct the house to make the system more efficient. Charlie Silva demos the third-floor ceiling to make room for new insulation. Meanwhile, Tom Silva and Kevin O'Connor install a double-hung window located in the dining room that looks onto the front porch. Back inside, Kevin and Charlie address a sloped floor in the parlor.