Search for Cycas CAD. It was aimed at Architectural and Engineering fields as well as Electronics and was not too bad about 12 to 15 years ago. It was being supported and improved upon for a while, but don't know when/if support and further development stopped. I believe it was based in Germany or another EU country, but had English support as well. I have a registered copy downloaded and saved on a floppy and some old hard drive around here somewhere.
I use TurboCAD for the PC now for the last 10+ years as it was very low priced and full of features. Once you learn one CAD program you are reluctant to start over on another and I am not rich enough (or stupid enough) to spend the thousands of dollars on any AutoCAD products. TurboCAD can read and write most AutoCAD file formats.
There are also several other Amiga CAD programs, InteliCAD 3D CAD, HomeBuilders CAD (shareware, I looked at it briefly, but never really tried it) and a few others I can't remember at the moment. I only tried and liked Cycas CAD and at the time I was looking, I think it was the only Amiga CAD program I could find that was still being developed, but others here will probably point out some others.
I have been ridiculed for even thinking of using something like Lightwave, or another Amiga 3D program for CAD, but still think it could be done if someone would write some CAD specific tools as an add-on for Lightwave, Imagine, or Aladdin 4D. It sure would be nice to only have to learn one program and be able to use it for both 3D animation, 2D & 3D CAD drawings and modeling with "walk-throughs/fly-throughs" that most clients want these days.
If only the Open Toaster/Flyer group could get the source for Amiga Lightwave as well as the rest of the old Amiga Toaster/Flyer software. Then some bright developers with more time than common sense on their hands could continue development of the Amiga Lightwave code, port it to Classic PPC Amigas, AOS4.x, MorphOS2.x and AROS, as well as perhaps write the tools to make it more usable as an Architectural CAD program too.
[Dream Mode Off]
Edit: Found some links to Cycas CAD
here and
here . It is still in development for Windows and Linux and I think for NetBSD too. Enjoy! :-D