Homeowner Gillian Pierce shows host Kevin O'Connor the progress - the first floor family room is entirely framed in, and up above, general contractor Tom Silva is building the gable-end wall for the new addition. Kevin climbs up top and lends a hand with the wall raising. Out front, master electrician Allen Gallant prepares to upgrade the service from 100 amp to 200 amp, but first he sets up temporary jobsite power by making up a new main connection from the street - with live wires. In the basement, plumbing and heating expert Richard Trethewey shows Kevin how he's using a composite pipe made up of PEX and aluminum to run new lines to the old radiators. Out at the new addition, Tom walks Kevin through the complex roof framing, and they get a sense of the new library and home office space for the first time.