One outdoor pen is used for breeding my pair, and I only pair them up during breeding season, which begins in April or May here in Florida. Iguanas can often be allowed free run of a house or apartment, although I recommend that they be caged when not supervised. Iguanas usually urinate and defecate in water, so they can often be house trained by simply soaking them in warm water daily. This will keep the cage clean, requiring less frequent cleanings. Some iguanas do not regularly go in water, and may choose the same location to urinate and defecate in, and in these cases, it is easy to place newspaper in this area, facilitating clean-ups.
Some people prefer to have an iguana as a pet because is so clean and quiet.
Apartment and condominium dwellers may be able to have a pet reptile, but not a dog, cat or bird. Green iguanas can recognize familiar people. The do seem to have definite preferences concerning people, although some rather gregarious iguanas will tolerate attention from anyone. Because the are arboreal, they will usually choose to lounge as high up as they can. They are often found in trees in their native habitat, and they do like to climb.