Reading this article, the thought occurred to me that perhaps it's the "building stuff" part of computing that women aren't as interested in, as opposed to the "math" part, which is the typical culprit.

So, did a bit of googling and found this article: http://www.archsoc.com/kcas/ArchWomen.html

Interestingly, via the table at the end of that article, the two professional occupations which had even less participation from women than computing are: Architects, and Civil Engineers.