I have a bit of time until my work space is available and I can start the conversion, so I'm making the most of my time by drafting floor plans. There are a lot of pieces to cram in 200 sq ft! Basically the size of my current bedroom and bathroom! Here's where I'm at right now:
Until I remove all of the seats and am able to do an accurate measurement of the bus dimensions, this is probably as much of the floor plan as I'm going to be able to finish. The length and width in this floor plan are estimates and I don't have measurements for the wheel wells, which obviously need to be taken into account. Some of the critical goals of the design at this point though were to get the water using devices (shower and sink) on the same side of the bus to simplify the plumbing. I also want the hot water heater as close to the shower as possible so I don't waste water waiting for it to get warm.
The drainage for the sink and the shower are together in this design which will simplify the location of the grey water tank. I'll be using a composting toilet so I won't need to deal with a black water (sewage) tank.
As for propane, I don't see any practical way to get all of the propane devices on one side of the bus, so I'll have to run a line to both sides (stove/fridge/furnace on one side, hot water on the other).
I also like that this design keeps a queen sized bed, though that might get downsized to a full in the final design. We'll see. The boxes above the bed aren't pillows, that's storage. And next to the bed is a tall shelving system to hold clothes.
The couch in the entry will pull out into a full sized bed when I have friends join me on the trip. The back area of the bus, accessed through the rear door, will be gear storage and the electrical system. The bed platform will be hinged to allow for more storage under the bed both from the bedroom and from the gear "garage" in the back of the bus.