The best is to build it once - for a live time. Iguanas hate change and it impacts them negatively for a long time. The best is to try and avoid doing things over and over again.

Here is a care sheet that I wrote about iguana habitats that will certainly help you a great deal.

http://www.reptileparrots.com/t128-care-sheet-housing-your-iguana

You can also have a look at my boy's setup as an example.

http://www.reptileparrots.com/t1-iguana-room-tunnel-and-outdoor-cage
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