I have the blueprint of a room in my flat as a planar 2D vertex, example:
I want to add walls to it that are going into the Z direction. I have tried several modifiers and searched with Google, but i have not come up with a fast and easy way to do it. Currently my method is to create a new, second vertex and measure all edge lengths, then recreate the shape and extrude it into the Z direction. There surely must be a better way, maybe with a modifier -- but how?