Free Zestimates – You Get What You Pay For 
So you’re thinking about selling your St. Louis home and want to find out how much it’s worth. When Zillow burst on the scene, buyers and sellers flocked to the site to get information once reserved just for licensed real estate agents. While it’s a great place to browse listings, relying on the Zestimate for the valuation of your St. Louis home might give you a value which is off by thousands of dollars or more. So how does Zillow create its Zestimates? Is it accurate?
Zillow and other similar sites use an automated valuation model (AVM) to determine a property’s value. An AVM uses the basic property information, such a square footage and number of bedrooms, to get a basis for its value. The system then accounts for publically available data such as price trends and local market information to arrive at its number. Zillow uses a complex proprietary equation which analyzes past sales to estimate your home’s worth. They access public data which only shows a change of title. They have no way to distinguish between a short sale, foreclosure and family transfer (which could be significantly different from a St. Louis market sale).
Because it’s an automated system it lacks the ability to factor in the unique characteristics of your home. For instance, do you have a spectacular view that the house across the street does not? The Zestimate does not include that extra feature in its value. What about your remodeled kitchen or spectacular outdoor pool and spa. There is any number of reasons that your home is in a different condition than the comparable properties Zillow uses to compare it with.
The Greater St. Louis area real estate has many custom and remodeled homes as well. It’s very difficult for an automated system to account for the unique properties of a custom home. Mere square footage or lot size is inadequate to really compare a Colonial Saltbox with a sprawling Ranch. Varying building materials, architectural style, lot characteristics and views can create thousands of difference in property value. The community itself and its amenities must also be considered.
It’s natural to want to do some research before you reach out to a real estate professional. The Internet offers a variety of ways to do this. But if you are seriously considering a home sale of your St. Louis area property and need a true value of your property, a licensed agent is the only way to get accurate information. Zillow’s Zestimate might be a ballpark figure you can use to get a feel for the value, but with some Zestimates off by thousands of dollars, it really isn’t a reliable even for a ballpark.