Exterior height will be 11 foot and the interior height will be 7 foot 8 inches. This box is mounted on a 2006 Columbia chassis that has the ultra-shift transmission. This chassis has 100,000 miles on it. The main reasonh for leaving the sleeper on is to accomidate 2 lazyboy style chairs for a separate sitting room, also we will have two additional bunk beds supported off the back wall of the sleeper if need be. Bunk over cab was not desired because of design of the box. We modeled the sleeper in a 3-D program and basically stretched it all the way to the back of the box. This gives it a more sleek look with the lines and contours of the cab to box transition. The floor plan consists of tripple slides, one being a 12' kitchen slide, another 14' opposing slide that will occomidate a couch and a small movable dinette, and the other being a 8' bed and closet slide in the rear. The reason for the movable dinette is to install a set of twin bunk beds against the outside wall the will fold down if we need extra sleeping areas, I believe lift-co makes a style of these. There will be all central ducted heat and air, 12.5 gal dual fuel hotwater heater, 40,000btu furnace, washer/dryer, corian counter tops, pex plumbing to each fauct with a pex manifold. The manifold will have a 3 way ball valve to shut off fresh water intake and accept antifreeze from a 5 gal onboard tank. This should take about 1 minute to winterize the conplete unit. Two 3 way ballvalves will be inserted before and after the hot water tank to ensure antifreeze does not enter this tank. All compartments will be insulated and heated, there will be 200 gal fresh water and 200 gal black and grey 160/40 staintess steel tanks. Walls, roof and floor will be 2'' thick insulation with 6 mil vapor barrior on each side. Alum roof with a rubber overlay, and only 2 roof protrusions for a vent and mobile satille dish.