I'm unsure of the most readily recognizable term among normal people to describe a group of windows in a building.
Here's an example of the type of architectural feature I have in mind. In this photo there are five distinct 'groups' of windows which I'm trying to describe:
Using the desired term I might say something like:
"Please look at the 3rd XXXX of windows from the left..."
Note that from a construction point of view each of those five is made up of multiple frames, pieces of glass (or "glazing units"), etc. but that lower-level of detail is not what I am trying to describe.
Thoughts so far:
The first term that came to mind was that each is an "array" - but I am probably biased by familiarity with that term from computer programming and it might be too obscure. However it does seem to capture the regularity of their layout.
The second idea is to call them each a "bank" of windows but the Google definition states it is things "grouped together in rows" which may not be correct - column groups also exist. (This may be too literal of a concern).
Again, being technical correct in an architectural sense is distinctly secondary to the meaning most people would infer from the term.