safe to build with???

I really want to build my chin a cage but am looking for the cheapest option for me. I have a greenhouse that i am not using and was wondering if i could use the aluminium frame to make a framework for a cage. Should i just frame with wood then cover either frame with 19g wire mesh internally. My thinking is that the mesh will stop escapes but all shelves and hideaways would be attached to the framework for strength. Any input greatly appreciated