Most of the infrastructure of the van was built up using wood and to be more specific, softwood and plywood. In the build section there's lots of pictures and details of what got built but below is a list of what got used.
Update May 2013.
All the basic woodwork has worked out well, but while the cladding was cheap and looked ok, it has suffered badly from the changes in temperature and humidity. I'm still considering redoing it all again, not a huge effort and or cost but as it stands it's beginning to look very poor and tatty with gaps appearing everywhere. A few doors have been rebuilt already.