Hi,
the plans are excellent, very detailed and well worth the money. Conversion between metric and imperial is covered , but if you can only source imperial sized materials then a little extra thinking is required.
I've never attempted anything like this before and so far haven't had any major mishaps, which is testament to the quality of the plans I think.
There are no details about adding a shower and to be honest I'm not sure how practical that would be, although there is plenty of headroom, there isn't much floorspace.
Mishaps.....one of my upper section panels doesn't seem to be completely flat, so I expect that may cause me some problems down the line when I come to assembling the top section. Hopefully I can pull it in to line...fingers crossed.
The plans allow scope for some variation in the length and width of the cabin depending on the trailer you use. The centre floor space is always 40mm so the bunks vary in width. In mine, the bunks are approx 187cm long (enough for my near 6ft frame) . I forget the width , but when put together as a full bed you could comfortably sleep three adults in there, no problem.
For a fold out loft bed....the top section walls have to slide down the outside of the bottom section , so it only leaves a 10mm gap for your bed fixings. Some kind of hammock arrangement might work, but bear in mind that will put extra weight on the fixings that hold the top section up when in camping mode.
I think 2 adult bikes would fit , but 3 would be a push.
I'm stuck in painting mode (booooorrrrrrring) and sourcing some materials, but will keep posting as an when I make further progress.
