If only i had a cat i would definitely make one of these; indoor/outdoor litter box
Outdoor Cat House Plans | Unfinished insulated Cat House with Heater
Cedar Outdoor Cat House Shelter: LEFT SIDE, SQUARE enter
Free Cat House Plans - How To Build A Cat House... possible house for our new outdoor friend.
Cheap Outdoor Cat Houses | Outdoor Winter Cat Shelter - a set on Flickr
Picture of Cat House (for the Winter and for Feral cats)
How to build an outdoor cat house and shelter. Add another entrance for escape and install cat flaps. Straw for insulation?