Alfred,
I tweaked the design just a touch this evening. Here's what I have so far..
It's built on a 5x8 chassis.
It uses weekender style construction.
The kids bed slides forward during the day so you can use the galley, and slides back at night so that you have room to sleep.
The adults have 18" of airspace for their legs, and the kids have 18" to sleep in also.
The adults have a queen sized bed (60x80)
The kids have a shortened queen (60x68)
Mike...
and if it looks like the body is way up in the air... it is... just like the Escape Hatch...

The quality is remembered long after the price is forgotten, so build your teardrop with the best materials...