I want to build a really simple trailer only for one person (myself) and only containing a sleeping platform with a foot-well so that I can sit on the bed and read. The unique thing is that I want the camping part of the trailer to be a removable, fold out "pod" which will sit inside my existing utility trailer which looks pretty close to this.

This gives me two benefits:
1. I can still use the utility trailer as a utility trailer when I am not using it as a camping trailer, and store the pod in my garage.
2. I am hoping that as the camping pod will not be permanently attached to the utility trailer (which is already IVA compliant) it will be in effect a cargo of that trailer and not subject to a new IVA assessment.
Some limit's I need to work within:
* The trailers cargo capacity is 350kg.
* The bed of the trailer measures 4 foot long by 3 foot wide.
I am hoping it will look somewhat like this, when configured for towing...

and something like this when configured for camping, but with rigid hinged extensions, not fabric...
I don't want any fabric sides or roof. I don't need a toilet, water, heating, AC, electricity or cooking facilities, just a window, door, bed and footwell.
Do you guys have any design inspiration for me, and specifically to the UK guys, what do you think about the removable pod cargo regarding the IVA?
Thanks, BigAl (The Scottish one)
