Since I have a red lacerta also I was looking at another forum and ran across a thread that got my brain to smolder a bit. Seems as if someone needed 4 enclosures and made one from this
adding a back and sides of sealed plywood and plexi sliders on the front
thinking for 4 units without lighting around $180
wouldn't want to take credit for someone elses idea just passing along info I found that seems an easy solution to multiple enclosures
I believe the gaps you see on the sides are covered in screen for ventilation. Only thing I would be concerned about would be heat transfer from cage to cage since there is no separation between each level. But all in all an inexpensive and easily constructed unit for a 4-level unit. The shelving unit is 4 foot X 2 foot and I suppose that you can alter each level to fit your needs.
a new one is less than $90 at home depot or lowes. I am about to move and am thinking of doing the same thing in the new house. Think I may even go the expense to have the rack parts powder coated to something other than plain old grey. This idea caught my eye and I think I can get it done under $300 even with the electrical. But then again thinking I have a resource that has some 1/4 inch plexi just sitting around that he will part with for some trade. I may get off even cheaper