We recently moved from our 3br house with a screened in back patio to a 3br duplex with no sliding glass door or patio. We do have a garage in the duplex now, which we did not have in the past. Two of my cats tolerate being on-leash but don't enjoy it and end up miserable outside. My other two I don't even attempt to leash. All four cats severely miss going out onto the patio. Any ideas or suggestions for an enclosure outdoors that is affordable but safe for them? Thanks!