The savannah monitor habitat should be large, secluded and escape proof. Although this sounds obvious, many monitor lizards have escaped from carefully designed enclosures. The monitor lizards are considered to be among the most intelligent of reptiles, and they are very strong when grown. If it can escape, it will.
Savannah monitors seem to like their privacy.
The ideal cage has only one transparant side. They like dark spots that are just big enough for them. You may notice that your monitor runs and hides whenever you move in from of it's cage. Approach it slowly, so that it can become accustomed to you. Light should be provided by a broad spectrum light that includes UVB components.