Zillow, the country's largest real estate listings website, has quietly removed a feature that highlighted the risks of extreme weather for more than a million home sales listings on its site.
The site began publishing climate risk assessments last year using data from risk modeling firm First Street. The goal of the assessment was to quantify each home's risk from flooding, wildfires, wind, extreme heat and poor air quality.
But real estate agents complained that they were hurting sales. Some homeowners protested the results, noting there was no way to challenge the assessments.
Earlier this month, Zillow stopped displaying the results after a complaint from the California Regional Multiple Listing Service, which operates a private database funded by real estate brokers and agents. Zillow relies on this listing service and others across the country for its real estate data. The California listserv, one of the largest in the country, raised concerns about the accuracy of First Street's flood risk models.
“Viewing the likelihood of a particular home flooding this year or within the next five years can have a significant impact on the perceived desirability of that property,” said Art Carter, CEO of the California Regional Multiple Listing Service.
In a statement, Zillow spokeswoman Claire Carroll said the company remains committed to providing consumers with information to help them make informed decisions. Real estate listings on Zillow now display hyperlinks to First Street's website, and users can click through to view climate risk scores for a specific property.
The development highlights the growing tensions within the real estate industry. Fires, floods and other disasters pose greater risks to homes as the planet warms, but it has proven difficult to accurately predict which homes are most vulnerable – and could potentially sell for less money.
First Street modeling has shown millions more properties are at risk of flooding than government estimates suggest.
Other real estate sites, including Redfin, Realtor.com and Homes.com, show similar First Street data alongside scores for factors like walkability, public transportation and school quality.
When researchers randomly showed these flood risk estimates to 18 million people searching Redfin, those who saw the feature were more likely to search for homes with low flood risk, according to a working paper published last November in the National Bureau of Economic Research.
The Redfin experiment, which lasted three months, affected sales of 8,150 properties classified as at high risk of flooding, reducing their overall sales prices by about 1 percent of their value, the paper said.
Zillow's own research has found that homes with high fire and flood risk scores are less likely to sell than homes with moderate or low scores, although the sales trends are not attributable to climate risk scores.
The California Regional Multiple Listing Service has asked the other major real estate listing platforms to remove certain flood risk details from their listings.
“When we saw that the chance of entire neighborhoods being flooded was 50 percent this year and 99 percent in the next five years, especially in areas that had not experienced flooding in the last 40 to 50 years, we became very suspicious,” Carter said.
In many states, sellers are not required to disclose information about whether a home has recently flooded or is vulnerable to wildfires. Other data sources, such as the Federal Emergency Management Agency's flood maps, have been criticized as outdated.
“Forward-looking models do not allow us to verify their results against records; they necessarily predict events that have not yet occurred,” said Madison Condon, an associate professor of law at Boston University who has studied climate risks.
“The First Street models may provide a good enough answer to certain questions or certain threats,” she said. “But what level of accuracy is good enough changes significantly when it comes to a specific property on which you want to spend your entire savings.”
In a statement, First Street CEO Matthew Eby said: “Our models are based on transparent, peer-reviewed science and the full methodologies are publicly available for anyone to view on our website.” He added that the company's models have been validated by major banks, federal agencies, insurance companies and engineering firms.
When Melissa Savenko, a real estate agent, listed a home in Richmond, Virginia, for sale last summer, she said it immediately sparked interest from buyers in California who were planning on hopping on a plane to view the property.
But then buyers saw that Zillow had a flood risk rating of seven out of a maximum of ten. They canceled their plans.
Ms. Savenko, who knows the neighborhood and sold the same house 15 years ago, thought the flood risk rating was a mistake. She tried to get Zillow to remove it.
“It didn't make any rational or logical sense at all that this one house was marked with this crazy flood risk and the houses around it had one or two flood risks,” she said.
Zillow does not allow sellers to remove climate risk data upon request. Competitors Redfin and Realtor.com do this.
Mira Rojanasakul contributed reporting.