I don't think polygonal walls will behave properly with windows. The reference line seems almost randomly picked when making them.
Try to model the variables with walls/collumns and sticking to as few stretches of wall as needed, keeping in mind where you want to be able to add windows.
With older buildings as-built models, I would sometimes put the interior trim on a layer with different intersection number, so the reference lines, building materials etc don't react in ways that I don't want.
Ussually you can analyse the building back to more reasonable walls (as in simplified back to the bare structure), that have lots of panelling etc added on the inside.
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
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