Zestimate works but value is different than zillow.com

TimboMT

I see a lot of posts about zestimate just plain not working or saying "no value for this property". I don't have that issue, but I do notice that when I click the zestimate button, I get an estimate that's a fair amount higher than if I navigate to the website and look up my property. I'm not sure who to believe at this point.

jtemplin

Personally, I find the most reliable home value information comes from

A local realtor who is experienced in your area. Get to know one.

Local realtors mail out periodic flyers listing comparable sales in the area (trying to entice you to sell).

The public records of sales in the neighborhood (in my county, all that is searchable online at the county property tax appraiser's website).

The S&P CoreLogic Case-Shiller Home Price Index for your area.

Now, I live in the Retirement Capital of the World™ and the place is crawling with knowledgeable realtors and there is relatively high-turnover of houses so there's lots of sales data. YMMV. A few times a year, I take these sources and update a Quicken asset account with the current estimated value of my house. The Case-Shiller Index has shown high correlation with the other sources so I find it very useful.

NotACPA

@TimboMT So what? An estimate is an estimate … it's not gospel. And, for absolutely any topic, experts frequently have differing opinions.

The only amounts that truly matter are: What you paid to acquire the property, any improvements (add to cost basis) and what you sold it for.

All the rest is guesswork.

retird

Zillow recently updated the Zestimate algorithm to incorporate new enhancements and even more data. To calculate a Zestimate, Zillow uses a sophisticated neural network-based model that incorporates data from county and tax assessor records and direct feeds from hundreds of multiple listing services and brokerages.

Neural networks are artificial intelligence systems that imitate how the human brain works. They are able to map hundreds of millions of data points efficiently, drawing connections between inputs and using the relationships formed to produce or predict an output. In the case of the Zestimate algorithm, the neural network model correlates home facts, location, housing market trends and home values.  

The Zestimate also incorporates:

• Home characteristics, including square footage, location or the number of bathrooms
• On-market data such as listing price, description, comparable homes in the area and days on the market
• Off-market data — tax assessments, prior sales and other publicly available records
• Market trends, including seasonal changes in demand

Zillow publishes Zestimate home valuations for over 104 million homes across the country, and uses state of the art statistical and machine learning models that can examine hundreds of data points for each individual home.