Inserting boundary lines of existing building

SketchUp
1

Hi, I somehow need to insert boundary lines of the existing building, to show the difference between the new building. Can someone help me with this please?

Thanks

2

And your ‘boundary lines’ are in… DWG format? SKP format? Other format?
Use File > Import

3

I don’t have them in any format… is there some way to draw them onto the Sketch Up plan?

4

One possibility, open a new file draw the boundary lines, export as a .jpeg, bring it into the existing drawing as a watermark, place it on the origin and place the existing building in the proper position.

5

What information do you have to help you draw these boundary lines? You have to have something. How do you need to show them? Are you going to use LayOut to create a document that shows the comparison between the old and new? If you share what you have to work with, it will certainly be easier to give you guidance.