Using Zillow to obtain an accurate date for when a house was built is not a good idea.  Zillow dated the build-date of my grandfather's house many years after my mother had already grown up there!  I knew the house well, and spent lots of time in it myself.  Zillow was WAY OFF.  I have no idea where Zillow gets their information, but I would definitely not rely on its accuracy.

Chana Bonn, Philadelphia
(KAPLAN, PERESMYK, APPELBAUM, GELBURD/GILBERT)