If you have a rough area, you can guestimate and T&E with fitting. As long as the building had a congruent area, it would be one way to go about it. Think abo

If you have a rough area, you can guestimate and T&E with fitting. As long as the building had a congruent area, it would be one way to go about it. Think about it like you just finished a jig-saw puzzle, but there's an extra piece and for fun you decide to try and find its twin.