The buns' room has been undergoing changes, much to their disapproval. Basically I took apart the storage block cage that was part of a double exercise pen setup and re-purposed some of the materials so they now live on one level (except for box scaling).
2 Before shots:
The 3 level cage always bent in that spot, despite having supportive dowels underneath, perhaps because of the pegboard platform anchored above it. The cage served as an anchor to each of the exercise pens which were attached to each side and then clipped together in the middle to provide an entrance for the human. I tried to use multilevel cardboard cottages in the past to give them some height, but Mercedes would bump them over to the side of the exercise pen, climb to the top level and hoist herself over the top of the exercise pen to freedom. This would upset Bertie, who is too small to perform such a maneuver.
The cage contained their litter box on top of a coroplast-covered pegboard floor, a mezzanine ledge, and ramps to a larger ledge with pad for them to share, and another small ledge on the very top. If Mercedes was excited, she would jump from the ramp onto the floor of the exercise pen area, but again, Bertie was really too small to attempt this. They still had room outside the cage for a maze and the remnants of their fort (they collapsed the connecting tunnels early on).
2 After shots:
They haven't lost that much with one-level living: they have 4 boxes (which haven't been used to Fed Ex any cats anywhere) and 2 tunnels (concrete forms, nice and durable). There was an excavation project they had begun previously relative to the vinyl tile which is now covered up by the former pegboard floor of the cage, the pegboard itself covered up with some of the coroplast (for some reason they do not chew the coroplast). The two exercise pens have been extended by the use of the storage grid panels that made up the cage, giving them more floor space.
As you can see, they still have room for their lounging pads, dishes, toys, and hay box. They have begun renovations on the flooring of the new boxes and once they have accomplished that to their satisfaction they will probably move on to climbing on the tops of them and renovating the roofs they are standing on. The tunnels are made of sterner stuff and usually just receive a few nibbles on the end rather than meeting a death from structural failure.