
As the entire world already knows, Zillow launched yesterday. The very first thing that I estimate over 500,000 people did (when the site was not down… maybe a great marketing ploy?) was enter their home address to see what it was worth. (BTW - nice IP to mailing address collection tool, but that’s another post). Most users were either pleasantly surprised or disturbed by their estimates.
The general public who knew nothing about Zillow until yesterday were impressed (unless their estimate was lower than anticipated), yet most who have been following Zillow appear to be initially under-whelmed, until you consider the long term possibilities… again another future post.
I spoke to a lot of friends who looked up their places and found estimates that seemed fairly accurate while others appeared to be dramatically off. This got me thinking about how accurate can it be and should people take the estimated value as gospel. So a few hours later, here are the results of my small test.
The Accuracy Test of Zillow Estimates.
First off, let me say that this is a very small random sample. In reviewing the Zillow site, they claimed they were best at the mid range properties on the West coast. So I based my random sample on the following:
25 Properties that were listed for sale by REALTORS on my local MLS and sold between 2/01/06 - 2/07/06. I took the mid-range (in California) of $500,000 - $700,000 for various cities in the San Gabriel Valley and western San Bernardino and Riverside Counties. I obtained the data via my
MLS. I also removed the High and Low to give a more accurate average.
I then plotted the listing price, sold price and the Zillow estimated value data on a chart.
Here are some highlights of my test.
It appears that Zillow is in fact within its claimed margin of error. In fact it appears (from my small sample results) that they are typically off by 2%.
There was some major discrepancies where Zillow was either high or low by over 21%. I removed these anomalies from my sample data but here are the properties in question in case you’re curious. (Note I did not do further research to see why such a big swing and why both properties where in Monterey Park)
Property | Zillow Est. | Listed Price | Sold Price | Error Margin
438 Sefton Monterey Park, CA | $794,134 | $638,000 | $615,000 | 129%
3054 S. Addrienne MP CA | $397,137 | $539,000 | $505,000 | 79%
As you can see from the results, overall they were pretty good. Would I take this as gospel… not. I would not suggest clients to price their home exclusively on the data Zillow provides but a combination of Zillow results and active and current listings from both realtor.com and homepages.com where available.
A trend that I do see this creating is prospective home sellers ordering property appraisals before listing their homes for sale. This only makes senses and it’s incredible that it’s not more common place considering how many real estate transactions blow up for this very reason.
The biggest issues I see with Zillow (which is obvious) is that it does not factor in certain aspects of a property such as specific location, views, improvements, lot slope, etc. that will make a specific home more valuable than another… but this is expected. As for traditional track housing, it’s pretty good.
The real reality of this tool is that it does a better job than most real estate agents can do at presenting the information in a clear, concise manor that is easy to understand to the general public. This will lower the overall perception of the value of the REALTOR, which will most likely lead to long term decreases in real estate commissions. This appears to be what Zillow had in mind.
Real Estate “Super Consumers” will become the norm. They will spend months understanding the nuances of the community they are interested in buying or selling. They will know crime rates, property values, school district information, job rates, etc… better than most REALTORS in their own communities. This consumers will be able to demand lower real estate transaction fees.
I also think that it is one of the biggest advances in real estate in years (although AVM have been around for at least 5 years, it was not publicly available for free and on this scale) along with current mapping technologies such as Google Maps, Google Earth and what A9.com is doing. I think that it will be a boon to the “for sale by owner” community as they are now armed with both pricing tools and easy effective advertising for their real estate listings.
I believe that FSBO market will gain some serious traction over the next few years (easily reaching 20% market share like in Madison Wisconsin) because of these “super consumers”. I also predict that the national average real estate commission will come down to 3% total but hey, time will and I’ve been wrong before.
Download my PDF paper & chart of this testIf you have any real life data samples, please post them here. We are looking for recently "Sold" listings & the Zillow Estimate, to make a running list of how accurate or flawed Zillow is.