When it comes to guinea pig cages, they can technically be as high as you personally want, however it’s important to bear in mind that Guinea Pigs are not climbing animals so do not naturally desire tall cages, as rats, or even hamsters do, although they do add variety and different areas to explore, and can be useful when separating off food areas.
Another thing to remember is that ideally at least one level, of any height cage, should still meet the minimum requirements for the number of animals housed there.
For example, a 3 tier C&C cage for 2 guinea pigs, should have one level that is at least 2x4.
Although it may sound confusing as surely with more levels you should get more space you need to bare in mind the amount of space lost by having ramps etc. And also, the fact that if a minimum cage requirement for a bunny is to do 3 hops from one end to the other of it’s cage, you couldn’t just have three levels that allow the animal to do 1 hop from side to side on each.
Guinea pigs enjoy running laps around their cage so it’s important to ensure all open areas are secure to prevent pigs from falling between levels. I made my ramps out of rectangular drain pipe with a rough carpet for added grip, previously i’ve used cat scratching posts, however these don’t offer sides for added security, although my pigs never seemed to have trouble with this.
Hope that helps, and good luck with designing your own cage.
