With the addtion weatherweight, its massing is apparement and seems to make a successful match with the old building. Inside, Tom Silva shows us the lightweight steel partition walls he's building, and Sima Maitland checks out the new windows and first floor plan. We then tour a plant in Tennessee where power tools - including the circular saw he follows from start to finish - are made. Back at the site, Tom Silva shows us how to the exterior trim on one of the new windows.