I'm having a bit of an issue finding a CAD program that suits my needs and was hoping that someone here may be able to point me in the right direction. I'm trying to take 2d .dwf roof plans distributed from a builder and lay plans for a solar panel array over those plans. Not a terribly complicated task, but it has been giving me endless amount of trouble. Also, I MUST be able to save the plans of the solar arrays as templates to apply to future sets of plans.  I have little to no CAD experience, professional or otherwise, I've turned to CAD programs because it seems that they are going to be my only option of reading in the dwf files.  

The kinds of programs I've found that DO read in .dwf files all seem to be prohibitively expensive (ArchiCAD, IntelliCAD), so if anyone knew about the reliability/quality of dwf to pdf or dwg to pdf converters and would want to chip in any advice that would be great.

All of the internet research I'm doing is basically leading me in circles at some point, so any advice from a real human who knows a thing or two here would be much appreciated.

Thanks