Vector science is also basic building theory because forces are vectors (have magnitude & direction.
We have an intuitive understanding of how forces act on a body if we have lots of physical experience with building. But if we don't (& to improve on our intuition) knowing some basic vector science can help us avoid many common (& some potentially disastrous) mistakes in building.
Vectors are useful in figuring out how to build structures with the maximum strength & minimum materials.
... to be continued
Vector Analysis Summary for Physics Students - the beginning bit is basic,
the rest a little more complex ...
Also see TED Talk related to this under Innovation
there's a whole lot of spaghetti structure videos in YouTube!