Hello how may I help you? how much space do i need for a cat depends what kind. some are more active than others a fat cat 800 square feet is good for a sedentary cat what about an active one 1600 square feet and ideally an open area to play in so 500 sqft wont work it can work but the cat may get bored playing with it will alleviate this do i need a cage no cages are inhumane