Plot: In the last episode of the Auburndale project, master electrician Allen Gallant finishes up the exterior low-voltage lighting, while inside, lighting designer Susan Arnold shows off the installed lighting plan and how she's made a house with low ceilings look more spacious. Upstairs, host Kevin O'Connor meets plumbing and heating expert Richard Trethewey in the kids' bath to see the water-saving plumbing fixtures, and a bath fan that will turn on automatically when it senses humidity in the room