Lyric discussion by ephtee 

Cover art for Buildings lyrics by Regina Spektor

I think it's about a woman who's an alcoholic and her husband, who stands by her.

I think the buildings reference is what he says to himself almost as a mantra for why there is still hope that despite how bad off she is ,there is still hope for her to get better. As in "he would hold her hair back and hope, saying "they build buildings so tall these days...", "he'd give her time saying they build buildings so tall these days".

If you notice it's always HIM saying "they build buildings so tall"... he holds her hair back, cleans her up constantly saying to himself "if they can build buildings so tall, anything is possible - she can get better so I'll continue to wait and support her".

thats how i interpret that sentance too.