Architect David Stirling and homeowner Kim Whittemore go over plans for kitchen renovations at the Winchester, Mass., house. Outside, workers dismantle the top of an unused kitchen chimney, while landscaping contractor Roger Cook and an entomologist look for ways to save hemlock trees from a blight that has been killing trees in the eastern U.S. And on “Ask this Old House,” questions include how to deal with mosquitos. Also: contractor Tom Silva helps a homeowner “hide” an unattractive back stoop. Steve Thomas hosts.