That's really interesting. We'd love to do something similar to open up the downstairs, especially as it can be quite dark. Sounds like we have the same arrangement as you i.e smallish galley style kitchen at back downstairs and bathroom upstairs and would be great to make it more open plan. Not sure we could use the loft space above the bathroom though as we have quite a big drop down into the bathroom, so imagine the loft would be lower than the main loft.