Well my family is in the middle of moving and i was going through the stuff in the basement and i found a white shelf unit box type thing lol that you stack on top of one another. so i took one and possibly in the future once we move i was thinking about turning it into a wooden enclosure for possibly a small lizard species or a young/small snake species, it'll most likely become a new home for a young corn snake or a new home for my leopard geckos. the shelf unit is roughly 13.25" x 13.75" x 14" and i did the math and its roughly 10 1/5 gallons. i was thinking of siliconing the sides so nothing can get in or can get out and to make it water proof. and for the front put a sheet of plexi-glass and cuts some of it out or cut it in half to make a door. also i was thinking of leaving the self in there as an upper leaving giving it more floor space, and unless i did the math wrong it would make the floor space of the enclosure equal to a 21gallon terrarium. the one problem is the heating. i've heard that Under Tank Heater used with wooden enclosures can start a fire and thats the last thing i need so can someone confirm that? and also i don't want to use a lamp as a heat source because if this works good i'd like to make more so i can increase my collection while at the same taking up very little space by stacking the enclosures. thanks for the help i'll try to get some pictures of the shelf unit soon.