Made myself a buddy box. It can house my portable toilet which is purely for emergency use. It also acts as a seat, table and step for climbing upstairs. Constructed from 18mm pine furniture board with a ply lid and floor. All cut to size for free at B&Q. Painted inside and out in two shades of Cuprinol garden Shades paint, which is very easy to use and gives great finish.
I had one similar with a cushion top in my T25 no one knew it was actually a portaloo box. I think it was a Devon original.