Ability to add more building blueprints onto other unbuilt blueprints

So that you can plan your base layout without having to build, deconstruct, build, deconstruct, over and over again until you find something you like. You just get a big building blueprint with no resources put into it, and then you can start funneling materials into each section (ideally not the whole thing all at once).

It would be even cooler if we could save and share these blueprints and move the entire model around to see how it fits the terrain.