Walt, I think the OP means a double bunk. A few
Casita SD's have the factory side bunk option, not many.
Scamp does not offer side bunks, only the front bunks.
Parkliner offers it as an option, not commonly ordered.
A search turned up one thread, not too helpful:
http://www.fiberglassrv.com/forums/f...mod-65618.html
I vaguely recall one well-executed side bunk mod in a
Scamp or Casita- might the one the OP saw, and I remember thinking, "I like that because you still have the big window." Maybe someone else will turn it up.