My workflow is this:
I create floor plans in 2D cad and export to sketchup for 3D modeling. I detail the model to construction drawing level of detail. Pull the finished model in to layout so that I can export “to scale” images back in to CAD for use in my construction drawings. This process really works well for me, but the only problem is that my file sizes are really large when creating the pdfs for printing. I have discovered that I can reduce the resolution of the jpgs, but the line quality is greatly compromised. Anybody else out there with this workflow? Or am I an odd bird?

I think there are probably others who have the same issues. You have two options for managing image file size…one, when exporting from LayOut to CAD and the other when exporting from CAD to PDF. I’ve found that I have a hard time managing the exact file size in most programs because they don’t allow that much control over compression. Like you stated, you get a poor quality product when reducing JPG resolution.

My only advice is that when printing from PDF, file size shouldn’t matter and higher quality, or bigger files, is needed for good quality prints. If also uploading or emailing, then you may need to consider exporting High Res and Low Res versions of the PDF. I use Acrobat Pro to ‘Save as Reduced File Size’ to make smaller versions of my High Res PDFS when needed. I know that didn’t directly answer your question but there are some limitations to what your asking because of trade offs in quality. Only workaround is whether your images can be exported as Vector linework instead of Raster which might change file size.

I appreciate the response Eric. I also use Acrobat Pro. I had not tried that “reduce file size” option before. Great suggestion!