In need of suggestions and help about best way to add a small additional bedroom. I'm a single parent with two children with additional needs who really need their own space (even if box bedrooms). The loft is far too small to convert sadly. We live in semi-detached so wall to right could have planning permission for window to be added. Ideally would like all bedrooms upstairs. Open to moving walls upstairs, moving stairs, moving bathroom downstairs if space for upstairs toilet. The dotted lines show where current support joist is, unsure how easy/ costly to move. Biggest property could afford on budget and I'm locality of needed school, garden is 25ft in length currently, will be unable to move for least 7-10 years so need to make it work. Design suggests welcome, thank you!