Zillow vs. Reality: Our Methodology

Between January 16 and June 14, 2019, we tracked and recorded the closing prices of existing single-family homes in the Tri-Cities and their Zestimates® as shown on Zillow.com on the same day that the sale closed. This was done manually each night* by reviewing homes marked as sold that day in the PACMLS system and inputting each one on a Google Sheet (address, city and closing price). We then located the home on Zillow.com and added the published Zestimate® for each home sold to our spreadsheet. We only tracked a home if we could verify that the sale had closed that day and we could retrieve its Zestimate® within 24 hours of the closing.

We focused on the four cities in the Tri-Cities area with the most real estate activity: Kennewick, Pasco, Richland and West Richland. Smaller cities/towns weren’t tracked because of the possibility that the lack of consistent real estate activity in those areas might negatively impact Zillow’s ability to offer accurate Zestimates®.

Our research focused solely on sales of existing homes. We ignored sales of new construction and vacant land on the assumption that Zestimates® for those sales would be less accurate or not available. We also ignored sales of homes that were listed as being in foreclosure — a tiny fraction of Tri-Cities home sales — because a foreclosure situation often creates sales that don’t reflect a home’s actual value. We ignored sales if the home couldn’t be found on Zillow.com, or if it didn’t have a published Zestimate®.

Via this process, we ended up with a collection of 532 existing home sales.

(*We estimate there were about 5-10 nights when no sales were tracked. This was typically due to things like travel, the internet/MLS/Zillow being down and even a couple nights where we simply forgot to check that day’s sales.)

We used the free Beam chart maker from Venngage and art from Freepik.com to create the graphics that illustrate our data.

Navigation

1. Zillow vs Reality: Introduction
2. Zillow vs. Reality: Key Takeaways
3. Zillow vs. Reality: All Tri-Cities Zestimates®
4. Zillow vs. Reality: Kennewick Zestimates®
5. Zillow vs. Reality: Pasco Zestimates®
6. Zillow vs. Reality: Richland Zestimates®
7. Zillow vs. Reality: West Richland Zestimates®
8. Zillow vs. Reality: Home Value Comparisons
9. Our Methodology (this page)