Faon door come 5x7 - if you need a specific size, let me know and we can make round holes of 6 if you want too. Just leave a note to your order if you need a specific size or door shape. The lid on the top is on weatherstripping for a waterproof seal and is articulated with a latch. All holes or gaps are filled and the entire house is sealed with weather-resistant lacquer. Glued and tied together for a strong grip.Isolation is also an option. We use reflectix sheet insulation, it radiates the body heat of your cats, like a cover of emergency aluminum foil. A 1/2 foam board is also placed below. The floor of the shelter is raised 3/4" on the floor, but we also have 4 "stands for the shelter to sit on to avoid sitting in any standing water. This 3' shelter could house any o of 2 - 6 + cats, it really depends on their size and the amount of plush - (gras) they have for them: therefore, please take measures in consideration.