Here's the very thing if you like to mix your shedworking with water. Camping Raft in Holland. Built of tree trunks, each floating raft is 25 square metres and has its own 12.5m hut. The package includes your own canoe as well as mattresses, stoves, matches, lavatory bucket and small broom. The rafts are spaced well apart among reeds and you need to paddle the canoe quite a bit to reach them. According to the site "extended sanitary facilities are present within acceptable distance" so no need to worry. There's a great 360 photo thingy here.