You could also check out this site.
Good resource for a lot of large cities almost anywhere on Earth, so depending on where you live you could get anywhere from DWG plans to trace over, up to and including 3D for the surrounding context buildings (sketchup, Rhino and DXF/DWG formats) that you can import into ArchiCAD.
I find it's best to use a multiple variety of sources.
With most large cities it helps to check with you local large universities or college's Geology departments that typically keep a downloadable database of the GIS Geological survey information with site contours and linework that ArchiCAD can import directly.
As mentioned, most city departments also keep downloadable digital(DWG) databases of their municipalities road, site, and even building outline files So be sure to check with them too.
And of course the easiest (or at least most accessible) is Google Earth Pro (if you have it)and Google Maps which you can download from directly from your browser (but in rasterized JPG format, so less accurate but good enough for tracing over).
Sketchup used to have the ability to extract sites (including 3D height and neighboring building 3D) directly from Google Earth, but unfortunately since they were sold off by Google and bought by Trimble, that capability has been seriously curtailed.
You can still get good site snapshots to use as a basis for modeling your site Mesh or even in place of a mesh.
It's been a life-saver for me in the past.