I checked online and found several free plans. My husband wanted to build our cats one. When he saw the materials list, he had a fit. "this will be too expensive to build!!" I told him to get online and check them himself. He liked the one that used an old step ladder. Shelves were added and everything was covered with carpet. He has the carpet and the ladder. His staples were too short to attach the carpet. He put the ladder in the garage for the cats anyway and they are enjoying the shelves with the carpet just laying on them. I doubt DH will bother with doing any more since they are happy. . .