talexb:

Like wjw, I've done a good bit with DXF files some time ago (pre-2K). I'd ask your colleague about what the drawing conventions are. AutoCAD doesn't really care about the concepts the geometry represents, but the people using it do. So you need to find out what conventions they use to represent the different parts of the drawing. In the jobs I recall, most of the interesting concepts were captured using layers, where one layer could be the property boundaries, another layer could be foundations, etc. Some other concepts were indicated by line types as well.

I've never seen anyone using Lat/Lon in a drawing, so you'll definitely need to translate for at. So you'll need a direction and scale references too, so be sure to ask about that.

One of the jobs I did used DXF files for locating electrical systems (transformers, power distribution boxes, etc.) so we'd have position. But some of the drawings had the floor name encoded in the drawing name, rather than put anywhere on the drawing itself. So you may have to prepare to merge the drawing data with some external information source, as well.

Back then, the drawings were by humans / for humans, so you may need several iterations with various examples to capture all the desired information. The drawing technologies have continued to advance, though, so things may not be as finicky now. (In a later robotics job we were extracting sections of ship plans for the purposes of cutting parts and welding hull sections, so we were able to push a bit of rigor into the drawing side of things.)

...roboticus

When your only tool is a hammer, all problems look like your thumb.