Like anyone else, dogs need snug shelter in cold weather and a place to escape the direct sun in warm weather. A basic doghouse deflects rain and wind, but provides little or no way to hold warmth. Insulating your dog’s house helps to block out cold and retain your dog's body heat. A well-insulated doghouse, packed with plenty of dry, clean bedding material, is essential for any dog who must spend time outside. Such shelter is especially important for puppies and older or frail dogs.
Install a vapor barrier between the doghouse floor and the ground or concrete it sits on. This vapor barrier, made from a tarp, space blanket or heavy plastic sheeting, prevents cold air and dampness from seeping up through the doghouse floor, and keeps body warmth from escaping. Replace the vapor barrier when it is torn or moldy.
Use a platform under the doghouse. A wood pallet covered with a plywood top lifts the doghouse above wet or cold ground. You can easily insulate the pallet with rigid foam sheets or bubble wrap stapled to its underside. Avoid household batting, as it is not efficient when it gets wet, and it makes good rodent habitat. Cover open sides of the pallet to keep the insulation in and dogs out.
Make a floor sandwich with insulation fitted against the floor and covered with more plywood. Home centers sell rigid foam with vapor barriers, foil-faced products and other insulation options. Put the insulation on the outside floor to maximize interior space, or inside if the house is roomy.
Insulate the ceiling of the doghouse to protect against winter cold and summer heat. If space is at a minimum, use foil-faced paper, plastic or bubble insulation. It cuts easily to fit against the ceiling, and it can be stapled up, then covered with paneling to keep pups and bored adult dogs from ripping the insulation and possibly ingesting it.
Reinforce a flimsy dog roof by installing rigid foam insulation. This type of insulation comes in sheets. Cut to fit, it provides both thermal resistance and structural support. Cover the installed foam sheets with paneling or plywood to protect it from the dog's curiosity.
Cover the outside roof with a tarp or house wrap to cut heat loss from the inside and to block cold rain or snow from the outside. Remove these temporary air barriers in summer to allow natural ventilation.
Use the insulation sandwich method on doghouse walls, placing insulation between the wall and a protective cover. If the doghouse is small, place the insulation and wood cover on the outside wall to save precious interior space, or use foil-faced insulation for inside walls and cover it with paneling.
Hang carpet remnants along the inside walls. This requires a sturdy doghouse with a frame. Install cup hooks along the top frame, then snag the carpet over the hooks so it hangs down and lines the walls. This is especially helpful in dry climates where cold is a factor but carpet-rotting moisture is not a serious concern. Unhook and remove the carpet in summer to increase ventilation. Monitor your dog carefully when you place any materials in his living area to make sure he does not begin chewing on the materials. Very serious consequences can follow if a dog swallows a mass of material or its threads.
Wrap the doghouse with commercial woven synthetic materials such as Tyvek and Typar. These materials block moisture and keep warm air in the doghouse. Be aware that if rain or other water drips behind the wrap, the trapped moisture can cause wood to rot.