Strangely enough, Buyer, I was going to ask the esteemed company at Piggington’s the very same question….
Seems that Zillow was actually updating weekly as late as August.
September – 1st and 15th (current) appears to be bi-monthly – except that that would mean an update on 30th sept, 4 days ago.
I can’t seem to find any info from Zillow themselves as to when they will update, or why they are updating to erratically. Like others, my guess would be lack of sales data for comps.
Seeing as I’m using the Zestimate as an upper price guideline, I would like to know when I have to trawl through the 60 or so places I’m tracking on Zip to see a difference.
Yes, I know, Zestimates are notorious for their innaccuracy, but in conjunction with previous sales data and even tax assessed value, it gives some indication of which prices are going for a particular property. I’d rather see no change on a weekly basis, than waiting a month and having to update like mad.