Chris Barreras, Payloads Engineer Responds:
A good design, Pablo!
You need to show what view are we looking at. I think it's the top view? This will give better orientation for the reader. Show width, length, thickness dimensions.
One of your basic thought processes should be "never assume anything
Do the fans blow the waste into the carbon?
What is the basic frame material made off?
Remember to make sure all the seams are sealed. Rodent urine finds ways to leak.
How do the lights and fans get power?
How are the animals loaded into the habitat?
Remember, you may have to open your habitat to do health checks.