2"-4" of real foam insulation in every panel Pass-through, self-closing, insulated door Insulated raised floor for a dry and warm bedding area The Dog Palace is a rotationally-molded plastic house. All panels of these products are filled with recycled ESP foam (commonly used as an insulation material in construction). To demonstrate the real value of insulation, we conducted an experiment on the Dog Palace with and without insulation. (Note: This product is only sold with insulation and door.) The results of the experiment reflect the heat retention inside the Dog Palace using a common 100 watt light bulb (no other source of heat). At an outside temperature of 40°, the insulated Dog Palace will be 70° inside, while the Dog Palace without insulation will be approximately 45° inside. At an outside temperature of 0° degrees, the insulated Dog Palace will be 30° inside while the Dog Palace without insulation will be approximately 4° inside. An average dog's body heat will raise the temperature inside the Dog Palace 25° in the winter without the floor heater (sold separately, available on {url removed}); therefore, if the outside temperture is 25°, with an average dog inside the Dog Palace the temperature is approximately 50°. The Dog Palace is ALREADY assembled. The dog entry door had to be taken down and replaced for smaller dog to get out. Will need a truck to take it away.... The Dog Palace is sized for medium to large dogs (Lab through small St. Bernard). Another unit available on {url removed} - the "DP Hunter" is sized for small dogs (beagles, basset hounds, pugs, etc.) or cats. Specifications 2-4" of real foam (Styro/EPS) insulation in every panel 38.5" H x 31.5" W x 47.5" L Easy pass-through, self-closing, well-fitted insulated door (not a "flap") Sized for medium to large dogs (Lab through St. Bernard) Self-storing window panes easily reposition from winter's closed position to summer's open cross ventilation position without tools Floor is insulated and...