How to Make a Room Above the Garage Warmer

Garage Ceiling and Doors

• If your home is relatively new, the garage ceiling is probably well insulated. However, an older home might need to have blown-in cellulose insulation added. Cellulose is highly effective at blocking the air flow that cools the upstairs room. You can cut an inspection hole in your garage's drywall ceiling to determine whether or not extra insulation is warranted. Warm the garage further by replacing an uninsulated garage door with an insulated one.

Air Ducts

• According to Energy Star, about 20 percent of the air that flows through heating ducts is lost in homes with forced-air heat. It attributes the loss to air leaks and improper sealing. Energy Star recommends insulating the exposed ducts in your garage and sealing leaks with duct sealant.

Weatherize the Cold Room

• Determine whether or not the cold room is adequately insulated. There should be enough insulation in the walls and above the ceiling to halt air flow. Add weather stripping around the windows. In addition, seal leaks at and near the floor level from the exterior of your home.

Heat the Floor

• Radiant floor heat counteracts the effects of cool air flowing through the floor, making the floor more comfortable underfoot and radiating heat into the room. Electric mat systems are easier to install than water-based systems, but you'll probably have to hire a professional to do the wiring.

Space Heat

• A space heater is a cost effective way to supplement your central heat because you use it only when you need it. Many types of space heaters exist, including several electric varieties, as well as gas and propane. Plumbing and heating contractor Richard Trethewey, writing for This Old House, recommends using a gas fireplace that's vented to the outside. Many electric space heaters are ventless -- they don't require venting, so there are no installation costs.