Recently completed this new camper for midsize trucks was designed with lightweight a priority.   It weighs 380 pounds empty which is about one third the weight of most commercial versions which average around 1000 pounds empty.  The payload on my stock Tacoma 4X is about 1100 pounds and with a full tank of gas and driver I can still add almost 500 pounds and still remain under the GVWR.  Mileage doesn’t suffer so much, starting and stopping is little affected and with a 6 speed manual transmission we still start off in second gear the same as with an empty truck. 

We opted not to design 6 foot headroom because we're most often sitting in the camper anyway and that has worked well, but we made that choice primarily to reduce profile in high winds and at speed. 

The interior can be laid out to suit individual needs, for solo or family use, or left open for modular furniture as needed.  Bunks can be fore and aft each side or sideways and removable.   There is space for a childs bunk overhead on each side if necessary, with feet extending into the cab-over section.  Doors and windows are an individual choice from traditional side windows of preferred size and a small or large entry door, plus an optional window in the forward cabover panel.  There is a 19 x 19 overhead escape hatch which provides good ventilation with windows open, and there is space on the top for two solar panels. 

We built the camper primarily of hardwood ply and glass cloth with WEST System epoxy. Its completely insulated with 1-1/2 inch foam and we carry a Goal Zero 1500 lithium battery which has an inverter to run 110 appliances including a small hot plate for coffee and running a small heater for a few minutes will warm the interior.  The battery charges phones and computers and provides lighting as needed.   

We are considering doing building plans but not yet decided.