Bob writes from Coventry, Rhode Island: "I recently built a room above my unheated attached garage. I insulated the garage ceiling with the vapor barrier pointing up toward the heated addition and the exposed insulation facing down into the garage. I plan to insulate the remaining three walls of the garage with leftover insulation from a prior project. For the walls, do I place the vapor barrier facing outward toward the interior of the garage or do I place the vapor barrier inward with the insulation exposed to the interior of the garage. I do not plan to heat the garage in the winter. Although the garage is cold in the winter, I am more concerned about the extreme heat generated inside the garage when the door is closed during the short summer months that we have in Rhode Island."

Answer: My friends at Owens Corning do not recommend insulating an unconditioned space. Doing so will create a "hot box." When the sun, ambient air and hot car engines heat the garage in the summer, the insulation will cause that heat to be retained longer.

If the garage shares a wall or two with the house and they are not insulated, you can place insulation in those walls to save energy and make the interior of your home more comfortable. That will also reduce noise transmission between the garage and adjacent rooms.