Home IN the Range

We give our users a stack of information about a house. Getting it all into our databases is a huge challenge but making it fit onto your screen is equally difficult. The Zillow Design Team works on that piece and they’re experts in making information easy to find and use. That said, some information still gets the bulk of users’ attention (i.e. maps & Zestimates), and other data seems to be missed.

The main point here is if you don’t go further than the map pages on Zillow.com, you’re missing out. That’s kind of like doing an internet search but not clicking on the links you get back. I doubt it’s a problem for regular readers of our blog, but I’m hopeful that you’ll inform your clients and friends when next the conversation turns to Zestimates.

A key piece of data that is commonly missed by users is the Value Range. Have you noticed it? Value Range appears just below the Zestimate on a home’s details page. To get there, search for a home, then click on “See home details” in the bubble on the map. The Value Range shows two dollar values; one greater and one less than the Zestimate.

How do I know that users aren’t seeing their Value Range? Because I investigate feedback from sellers who complain that their Zestimate is lower than their list price. It’s most often true in these cases that list is below the maximum value we show in the value range. Many sellers simply see their Zestimate on the map and then head straight to the feedback form to let us know how wrong they think we are.

The Value Range is the first place you should look if you doubt the accuracy of a Zestimate. A very wide range indicates that we’d probably agree with you. A narrow range is a clue that we have good track record of accuracy in that area (vs. sales prices) and that we’re more confident in the Zestimate. Value Range is calculated with the Zestimate and like Zestimates, Value Range also differs from house to house.

To illustrate this point, let’s look at two homes in Washington State with similar Zestimates but wildly differing Value Ranges;

House #1 is in Seattle’s Fremont neighborhood. Here’s its Zestimate and Value Range:

House #2 is on Whidbey Island in Island county (also home to the endangered Orcas of the Puget Sound). As you can see below, this Zestimate is very close to that of House #1, but the Value Range is far wider (by almost $150 K).

Why is this? Simply, our Zestimate is a better predictor of market value in King county than it is in Island county and we want you to be aware of that. We understand that the precision of the Zestimate value implies its accuracy and we want to let you know when we know that we could do better. You could have also discovered this (relative accuracy) by reviewing our accuracy table (see below) for both King County (73% within 10%) and Island County (62% within 10%).

We’re committed to transparently reporting on our accuracy, so much so that we do it for each and every house in our database. We’re also committed to getting better at it. All we ask of you is that you click through to the house details to get the full picture.