Appraisals and ValuationsMortgageReal Estate

Zillow is watching: New algorithm uses photos of your home to check quality and curb appeal

Zestimate’s upgrade is a "building block" for expanding Zillow’s iBuying, chief economist says

You know that dead shrub in the front yard that needs replacing, or the porch paint that’s flaking? Better take care of that if you don’t want your home’s Zestimate to decline. Zillow announced on Thursday it has a new algorithm that uses photos to help decide the appeal and worth of your home.

“We’ve taught the Zestimate to discern quality by training convolutional neural networks with millions of photos of homes on Zillow, and asking them to learn the visual cues that signal a home feature’s quality,” Stan Humphries, Zillow’s chief analytics officer & chief economist, said in a Medium post announcing the new algorithm. “For instance, if a kitchen has granite countertops, the Zestimate now knows — based on the granite countertop’s pixels in the home photo — that the home is likely going to sell for a little more.”

How does Zillow have photos of your countertops? Most pictures are provided by homeowners or real estate agents when a property is listed, the company said.

“These photos are either uploaded directly to Zillow or provided through a listing feed when a home is listed for sale,” Zillow said. “It is important to note, photos provided by previous agents or homeowners cannot be used for future listings.”

Homeowners who don’t want Zillow to use interior photos of their home can remove them. First, they have to create an account, then log in and claim the property as their own. From there they go to “Owner’s View,” click on “Add Photos,” then go to the existing photos and delete them one by one. 

For the exterior shots, Zillow uses images from Google Maps. In some areas, it adds its own photos taken from the sidewalk or the street, according to a company statement. It may also use publicly available photos taken by your city or town assessor’s office, the company said.

Also added to the new algorithm: Real-time data for homes listed for sale, including listing prices and how many days the properties have been on the market. With all the upgrades, a home’s Zestimate now has a median error rate of less than 2 percent for homes listed for sale, meaning half of all Zestimates fall within 2 percent of the home’s eventual sales price, Humphries said. 

The algorithm upgrade is an part of ramping up of Zillow’s iBuying business, Humprhies said. 

It’s “a key factor as we ramp up our business of changing the way people buy and sell homes through Zillow Offers, our home buying service that allows sellers in eligible markets to skip showings, repairs and open houses by selling directly to Zillow,” Humphries said.

Eventually, the company wants its Zestimate to be the equivalent of a "live" offer from Zillow, CEO Rich Barton said in April.

“Ideally I would like to have the Zestimate be a live offer for every house in the country,” Barton said in an interview on public radio. Barton said “it will take quite some time to get there,” but that’s “where we’re headed.”

Most Popular Articles

3d rendering of a row of luxury townhouses along a street

Log In

Forgot Password?

Don't have an account? Please