Pick the room like a keeper, not a decorator
The best free-range room has one door, few hiding gaps and little soft furnishing to ruin. Before your iguana ever sets foot in it, walk the room at his eye level — lying on the floor if you have to — and look for the under-door gap, the spaces behind and beneath furniture, radiator pipes, skirting-board holes and every other slot a determined lizard can pour himself into. Iguanas flatten to a degree that shocks first-time owners. Block what you find with boards, rolled towels and cable trunking, and treat this proofing as permanent, not a per-visit improvisation.
The danger sweep
Work through the hazards in a fixed order. Houseplants come out entirely, because many common ones are harmful if chewed and he will chew. Electrical cables go into trunking or up out of reach — an adult iguana's bite and claws make short work of a flex. Windows stay shut, or get screens that are genuinely structural; several pounds of climbing muscle treats a flimsy flyscreen as a suggestion. Other pets are shut out of the room for the whole outing, without exception, and anything small enough to swallow comes off the floor. If the room cannot pass this sweep, it is not the room — choose another.
Give him a headquarters
Free-ranging fails when the room offers the iguana nothing, because a bored iguana goes exploring cupboards. Build him a station instead: a thick horizontal branch or a padded shelf mounted where he can climb up and survey the room, a guarded basking lamp above it giving a proper hot spot, ultraviolet light over the perch, a large water bowl beneath — expect soaking, and expect him to use it as a toilet — and a hide at floor level for retreats. An iguana with a headquarters spends his outing travelling between the perch, the bowl and you, instead of testing your proofing.
Supervision and signals
Never leave him out alone, and learn his language before you need it. A relaxed iguana sprawls, basks and slow-blinks; a displaying one turns side-on, fans the dewlap under his chin, hisses and cocks his tail like a whip, which is exactly what it can be. During the breeding season even a famously tame male can turn territorial and unpredictable, and the correct response is shorter outings or a pause until the season passes, not a test of nerve. Start with short sessions — twenty minutes is plenty at first — and extend them only as his behaviour in the room stays calm and predictable.
The outing routine
Make entry and exit boringly consistent: same door routine, same station, same calm guidance back at the end, and never drag him from a perch he has chosen — a favourite food waiting at the station or back in the enclosure makes returning voluntary, and voluntary returns are the ones that keep working for years. Clean accidents the moment they happen, note how long each outing ran, and remember that the enclosure stays his home base for feeding, humidity and sleep; the room is a privilege he visits, not a replacement habitat. What KinsLe's Family Sharing shares is his profile: the relatives you pick are given access to it, and nobody beyond your chosen family gets in.