the actual living space is 18" D 30"w and 48" T. the bottom is a plastic tote that i cut a hole to fit it snuggly in the bottom. holes in the middle for drainage into my water basin. bottom back of cabinet is open to allow for chords and hoses. i also made the whole thing out of red cedar to avoid any rot from moisture. all together took me 2 days. still want to make a rail along the back for climbing for both chameleon and plants. carpentry runs in my family so this was a rather simple build