This is a large size house measuring 21"x21"x23"h on the outside ans 16"x16"x14"h on the inside. The floor is vinyl with removable carpet on top and The interior walls are lined with carpet, The floor, walls and attic are insulated. The house is heated by a 50 watt infrared bulb installed into a recessed light fixture in the ceiling so it is out of the way. There is an adjustable thermostat mounted inside the door, the bulb only comes on when heat is needed. There is also a thermometer mounted on the inside back wall. The house has a round plexi-glass window and 2 large doors that fit the biggest cat. The house comes with a 20 ft cord. The front of the house opens for easy access and cleaning. The siding and trim are left natural and finshed with a clear penetrating sealer.