A simple garage shelf unit can be built into a very nice stack of enclosure. Go through the gallery below to see how this is done.
basic shelf 
measure, cut, and paint side panels 
install back and side panels 
Install the panels from the inside so the shelf structure holds them in place when an occupant pushes outward
4 separate enclosusre spaces 
brackets on the inside 
drills holes for cords 
install linoleum a tape grout for wataer proofing 
don’t forget to seal the ceiling of each section to prevent mold growth 
LED lights and heat lamps 
Heat efficiently: the bottom cage has floor heat. Then each heat lamp acts as floor heat for the enclosure above it and is controlled by a thermostat with the probe on the floor above it.
