Don't make the mistake of starting with an iguana enclosure that's too small - iguanas grow quickly. The following table shows you the minimum enclosure dimensions needed based on the average size in snout-vent length (SVL) and snout-tail length (STL) for the first seven years. So, unless your iguana is full grown, when its STL is more than two-thirds the enclosure width, it's time for a new enclosure.
| SVL (in inches)) | STL (in inches) | Minimum Dimensions (in feet) |
|---|---|---|
| 2.5–7 | 9–18 | 3 x 1 x 1.5 |
| 8–10 | 20–28 | 3.5 x 1 x 2.3 |
| 11–12 | 28–36 | 4.5 x 1.5 x 3 |
| 12–14 | 30–42 | 5.25 x 1.75 x 3.5 |
| 14–16 | 35–54 | 6.75 x 2.25 x 4.5 |
| 18–20 | 45–60 | 7.5 x 2.5 x 5 |
| 20–22 | 50–66 | 8.25 x 2.75 x 5.5 |
| 20–24 | 50–72 | 9 x 3 x 6 |