In many rural places, sheds up to 200 sq ft do not require building permits. This is my current thinking of a floor plan for a 10' x 20' tiny house disguised as a shed or small barn.
All windows would have lockable shutters. The window behind the couch would be covered by 2 barn doors on the outside. A wooden ramp would placed below the barn doors to suggest that a trailer, lawn tractor or boat could be driven up and stored inside. No waste piping would protrude from underneath the tiny house, indicating that it is not being used to live in.