Pretentious real estate agent's BS.

An architectural "order" is a vertical succession of elements from the base to the top.

Villa Pozzolini di Bivigliano. It was easy to find the building by copy/pasting your text into google

This might not be the exact translation, but I think "assi" could be a standard Italian expression here, which we do not use in our type of descriptions of this sort.

I am sure this is what is meant, as this wikipedia article describes five simple window alcoves in this building, as "cinque assi".... (i.e., the "cinque assi" described here are clearly the five window alcoves between the pillars on the front aspect of this building).

"...con un prospetto principale inquadrato da lesene binate e scandito da CINQUE ASSI di aperture incorniciate poggianti su fasce marcapiano e portale centrale centinato con poggioletto superiore."
https://it.wikipedia.org/wiki/Palazzo_del_Governo_(Grosseto)

asse (plural assi) board; plank, entry no. 2 Collins-Sansoni.

I can see neither a window in the Italian, but nor do I have a mental picture of such 'asses'..

I suggested this to Tom, but he disagreed, so I'm posting it as an answer.

'Orders' is a technical term. People won't understand it, and it's not appropriate for this marketing document There are five vertical pairs of windows, creating an attractive rhythmic effect across the front of the villa.

"Window openings" is a tautology.

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Note added at 1 day 21 hrs (2023-10-16 14:11:12 GMT)
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Actually there are also small round windows at the top, so 'windows grouped vertically in threes' would be better.