Wire Shelf Cat Gate
Make a tall gate for a doorway! Find three wire shelves that are the desired length. Set the shelves end to end in a trapeziod shape with the long edge of the trapezoid empty and use zip ties to attach the shelves. Set the gate in the doorway, drill a hole on either side of the doorway and insert a gate hook in each hole. Wrap a zip tie loosely around the gate latch and shelf to make a hoop for the gate latch to hold and hang a bell on the top of the gate so you know when your cat is attempting to enter the room.