Zillow Expands and Improves Database of Homes

Real estate information marketplace Zillow® today expanded and improved its living database of homes, adding more than 25 million new Zestimate® home valuations and improving Zestimate accuracy nationwide. Zillow now has data, Zestimates and Rent Zestimates on approximately 100 million homes – more than three-quarters of all homes in the United States.

In the past five years, Zillow users have submitted information on more than 28 million homes, adding updates, such as remodel or home fact information, that are not reflected in public records. This gives Zillow an inimitable database of nearly every home in the country, and creates unique home profiles that allow Zillow to calculate more accurate Zestimates on more homes. The new Zestimate algorithms launched today incorporate more of this user-submitted data, among other changes.

The expansion brings Zestimates to homeowners, buyers and sellers in states like Iowa and New Hampshire, where Zestimates were not widely available.  The Zestimate median margin of error is now 8.5 percent nationwide, and below 6 percent in major metropolitan areas such as Denver, San Diego and Washington D.C.

"At Zillow, we have an unwavering commitment to give people as much free information about real estate and homes as possible, and Zestimate home valuations are a big part of that," said Zillow Chief Economist Stan Humphries. "We've spent six years cultivating our database of nearly all homes, creating a unique and living entity that combines public record data with information submitted by Zillow users on more than 28 million properties. By expanding the Zestimate algorithm to include more data points and new modeling approaches, we have been able to expand Zillow's footprint and improve accuracy. We are thrilled to offer this resource to even more consumers and professionals across the country."

Zillow launched Zillow.com in 2006, with Zestimates on more than 40 million U.S. homes.  Since then, Zillow has more than doubled Zestimate coverage nationwide, added 100 million Rent Zestimates, and made significant improvements to the breadth and accuracy of data. Zestimates are a starting point in determining a home's value; together with a home's value range, comparable recent sales, and current listings, Zillow's information helps consumers gain an edge in real estate and make more informed decisions. Zestimates and other home information can also be found on Zillow Mobile, the most popular platform of mobile real estate applications across iPhone, iPad, Android and Blackberry.

Zillow's Zestimate accuracy is published on its website, and updated every three months. More information is available at http://www.zillow.com/howto/DataCoverageZestimateAccuracy.htm.