Zillow has added more than 25 million new Zestimates to its database, bringing its coverage total to about 100 million homes, or more than three-quarters of all homes in the country, the site said.
A new algorithm takes into account user-submitted information not found in public records on more than 28 million properties, such as remodeling updates or other property details. The algorithm has improved Zillow’s median margin of error to 8.5 percent nationwide from a previous error margin of 12.3 percent, the site said. The margin of error is calculated by comparing Zestimates to actual sale prices.
Zestimate accuracy varies by location. Among major metro areas, margin of error ranges from 5.5 percent in Denver to 10.5 percent in Dallas-Fort Worth.
"Zestimates are a starting point in determining a home’s value," the company notes, and suggests that other data, such as "a home’s value range, comparable recent sales, and current listings" can also be useful to real estate consumers.