Do you build the exterior or interior first?

It's interesting how most seem to do the exterior first. The reason this comes to my mind, is that someone was mentioning that houses they download often have windows placed strangely in rooms, like right up against the walls. I know this is because if you want the exterior to have symmetrical window placements, rooms often end up with window placements that are asymmetric or right up against a wall. If you do the interior first, the windows are symmetrically placed for each room but the exterior looks haphazard.