Second Story Floor Plan Redesign

I have an existing ground-floor slab with plumbing already fixed in place, so the wet areas downstairs must stay exactly where they are. What I need is a fresh set of eyes on the overall layout to improve flow, open up the living zones, and avoid any rooms feeling cramped... (Budget: $30 - $250 AUD, Jobs: 3D Modelling, 3D Rendering, Building Architecture, Building Design, Drafting, Floor Plan, Home Design, Interior Design, Revit, SketchUp)