>This requirement is a contributor to US apartments being ugly.

US apartments look ugly because the IBC has been picked over by every flavor of money grubbing business interests masquerading as concerned do gooders. Once you filter out all the options rendered financially noncompetitive by each of their bought and paid for rules there's only a few paths to a viable building. You might have a dozen megacorps buying windows from a dozen suppliers but those dozen times dozen theoretical options are the same thing in practice because that's what it takes to hit Leed Platinum (TM) or whatever.

Seriously. Go watch some 80s/90s movies that were set in the then present day. Those cube farms have more diversity of style and material than anything today.