The design has undergone many mental iterations before arriving at the final product. Origially, I had mentalised a side pivoting murphy bed and a complex joinery installation with drawers built in. Both of these designs had a lot more permanency than the end design. I decided on something temporary and modular as I wanted to use the van for other purposes than just camping.
The design requirements/constraints/aims were as follows: Mattress
A double or queen mattress can fit in the van but there is little space for anything else. Also, as I am also quite tall a longer mattress is good for me (king singles are longer than double mattresses). Special caravan size mattresses are also available but they are shorter than doubles. Experience also shows that my girlfriend and I can sleep on a king single comfortably.
We bought a King single mattress quite a while ago with a view to building a frame for it later on. We have been camping a few times sleeping with the mattress directly on the floor of the Van. The problem here is that the mattress had to sit between the wheel arches which leaves little room for anything else. Portability
It was important to make the bed disassemble into small pieces so that it wouldnt take up much space when not in use. I wanted to use a semi-traditional design that used slats as these are good for the hygiene of the bed (allowing airflow underneath) They can also be rolled up into a bundle that does not take up much room.
I wanted to use a no bolt/screw fixing method so the bed could be assembled/disassembled without any tools. Accessibility/Storage
The bed was also designed around the need to provide as much clear space underneath as possible to provide good spaces for storing of camping gear/food. I am a big fan of using milk crates for storing things so milk crates were used as the standard storage unit in the design. Design
Using Sketchup, I drafted the outline of the floor plan of the van. The plan included the wheel arches to ensure the bed frame cleared this portion.
The mattress was imported over the top of the wheel arches and aligned to the right of the van. This leaves a passage down the left of the van. This seems like the logical side to align things as we park left side to the gutter in Australia. Storage units (milk crates) were then placed underneath. And finally, the bedframe itself was drawn around that.
The sketches below show the drawings used for procurement of the materials and the final one (rendered) shows the as built version. Model is available here or at 3dwarehouse.com