In Chapter 4, Flattening a Torus and Boolean Union, we compared the Object | Join feature with the Boolean Union. In the profile pendant project, the pendant and the hook overlapped, leading to some confusing extra vertices and edges left inside when Object | Join was used.
This project presents us with a solid and safe use case for Object | Join. The windows and doors of the house do not overlap with each other. This allows them to be joined and later they can be separated back out using the same Mesh | Vertices | Separate function we have been using.
You could use this to help expedite your work of copying vertices for the cutouts. You could join all the detail objects you want to cut out from ...
