Saving Blueprints by Section (Suggestion)

[BigMoser]

I like farming. When visiting a friend's farm setup, I like it so much I would like to copy it for a blueprint, but I have to select the whole building for the blueprint.

I would like to select just the foundations / walls / ceilings that are involved with just the farming part of his base and save it as a blueprint.

If that is an option already, I am blind and haven't discovered it and would like direction on how to copy sections of a base.