You can use side panels or a deck/surround to create what is, in effect, a free standing bath that would work well aesthetically and, optionally, as part of a wetroom-style bathroom. Deep soaking tubs are especially effective for such projects; they have smaller footprint, which affords more room in the shower area, but their greater depth makes them exceptionally comfortable.

I think rather than fixing any seating - keep it flexible - as despite being a floating home - it looks to me to me moored in one fixed location ? So if you keep the seating flexible you can follow the sun (or shade ) ... 2x three seater or four seater sofas could potentially double up as two sun loungers - might be worth looking at... are you thinking of an outdoor kitchen up there too ?

I was one of the original poster. Eventually in our case, building control wouldn't allow this - they originally OKd the plans, but then wouldn't allow the removal of the ceiling from the box room. There was a "galleries" approval that we explored but they weren't having that either.

Hi Daisy, Your old lean-to looks amazing, very similar to what we will be doing. However I want to cover up the decking with wood flooring (chipboard tongue and groove) then carpet it. What I was worried about is whether the decking would get damp under the flooring and end up rotting both. I really want to get rid of all draughts from the floor and heat the room in the winter so we can use it then too. It gets pretty cold up here in Scotland so I am insulating the walls and roof and fitting double glazing.