ok i have designed the run, will try to describe it, as your having it indoors/ in the garage you will probably want a solid floor so a sheet of wood could be your floor then you can cover it with bedding or newspaper just to keep there little paws warm as garage floors are cold, then you would some long pieces of wood like poles, sorry if I'm not describing it well, anyways you would nail the poles along the edge of the floor so they are laying flat the pole laying flat needs to measure a little less than what the edge of the sheet of wood does so you can attach the standing poles to the end of the lying poles, then its just like making a basic run by attaching the poles together to make a rectangle shape. then fixing the mesh/wire over it. the run can be detachable by having a bolt lock to the side of the hutch which attaches to the side of the run you can have one on the top of the run either side and one on the bottom either side. if you have a email i can email the drawing to you