Convert Sketches to CAD Drawings

I have site sketches and room layouts for an under-house (downstairs) renovation to my home in Darwin, NT. I now need them translated into a clean, professional 2D CAD package that my local building certifier and structural engineer can stamp without revisions... (Budget: $750 - $1500 AUD, Jobs: 2D Drafting, AutoCAD, Building Architecture, Construction, Drafting)