3D Planning Drawings for Extension

I already hold the as-built drawings for my property and now need a clear set of 3D exterior views that illustrate the proposed single-story extension. These visuals must satisfy British planning authority standards, so accuracy in scale, materials, and roof lines is essential. Please base your work solely on exterior perspectives; interior layouts are not required. If you believe an additional 2D elevation or site plan would strengthen the submission, feel free to note that as an optional extra, but my primary requirement is a polished 3D package ready for planning approval. When you respond, outline: • how you will model the existing structure from my supplied DWG/PDFs, • the software you intend to use (SketchUp, Revit, or similar), and • a ball-park cost broken down per milestone (initial model, first draft, final renders). Turnaround within a week would be ideal, but let me know what is realistic for you. I look forward to seeing how you can present the extension in the best possible light for the planners.