Best software for schematic design?

I apologize in advance if the question is a bit vague but I recently got a job doing conceptual and schematic designs for a house building company. My process involves a mix of sketches, CAD work, and volume studies using 3D modeling. I usually have to switch between manual sketches, AutoCAD, and then SketchUp for all three or those parts. Is there a way to steamline the process with a program or software solution that can integrate freehand sketching (I have a digital tablet), accurate drafting, and quick modeling?