In case you missed it…

In case you missed this morning’s first Webinar for Real Estate Professionals, you can access the archived presentation through Zillow’s Media Room. Thanks to all of you who attended. We had a fantastic turnout, some great questions, and Stan and I had a lot of fun. Speaking of questions, our only regret is that we ...

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In case you missed this morning’s first Webinar for Real Estate Professionals, you can access the archived presentation through Zillow’s Media Room. Thanks to all of you who attended. We had a fantastic turnout, some great questions, and Stan and I had a lot of fun.

Speaking of questions, our only regret is that we did not have enough time to answer them all! Below are just a few of the questions we weren’t able to get to (edited slightly for clarity and brevity), along with mine and Stan’s answers to those questions.

“Regarding data that goes into your Zestimates, are you capturing and incorporating any data from sources other than public records such as owner updated information, etc?”
-Scott from Windermere

Stan: The first layer of our data comes from public records, and includes information such as number of bedrooms, bathrooms, square footage, tax assessments and recent sales. In some parts of the country, we also supplement this data with information from multiple listing services. Finally, on every home in our database, we allow homeowners and listing agents to go in and “claim” the home, and add/edit any information we may be missing or needs to be updated. To date, 1.3 million Zillow users have done this. Taken together, these three sources of information create the most accurate and comprehensive database of homes in the nation.

“With, you can also view all homes. And their coverage is huge and very well known. How do you compare to”
-James from Kingdom Realty

Jorrit: Zillow’s database includes 80 million homes (not just those that are for sale right now through agents), which makes up approximately 3/4 of all residential real estate in the country. We have enough data on approximately 70 million of those to provide Zestimates – or our estimate of a home’s worth. With all this data we are able to generate really compelling market reports (discussed today) and we make it all available to you for free. In addition to Zestimates and data, we have approximately 2 million homes for sale, more than 100,000 Make Me Move homes, a vibrant community, free profile pages and virtually limitless free marketing opportunities for real estate professionals. In fact, as of today, we have over 130,000 real estate agents who have created profiles on Zillow and over 300,000 that use Zillow regularly. We also recently released the Zillow Mortgage Marketplace – which allows consumers to find mortgages and connect with lenders, and like the rest of Zillow, is based on free and annonymous information to consumers, and free marketing opportunities to professionals. Like other sites out there, we also have paid ways for professionals to promote themselves, should they choose. EZ Ads are a great example. These are rich, ZIP-targeted ads where you can promote your listings or yourself including complete contact information, for just a penny each time the ad is shown. We pride ourselves in being a real estate site “for the people” – and because we make our money off advertising, not enhanced packages or services, we’re able to keep our Web site free.

“How are foreclosures affecting Zestimates? If one community is experiencing heavy foreclosure activity, Zestimates for homes in (or around) that area will be negatively effected, right? Has the equation for Zestimates changed because of drastic variances?”
-Adam from California

Stan: Currently, increased foreclosure activity in an area affects Zestimates as this activity exerts downward pressure on the prices of non-foreclosure homes. As these non-foreclosure homes transact at lower than typical prices, these transactions are incorporated into Zillow’s valuation models, and the values of homes nearby may decrease as a consequence. Allowing these price signals to influence the valuation models required no changes to the overall algorithm, instead happening automatically as new data comes into our systems. We do constantly monitor market conditions to ensure that alterations to the algorithm are not required to account for significantly higher volumes of foreclosures in some parts of the country. At this time, we are satisfied that the algorithm is performing as it should.

“In this buyer’s market, with such a supply of product for sale, how far should (your) granularity go, relative to the true condition of the house? Are prices breaking out beyond “location location location” to “condition”?”
-Eileen from Elliott Bay Associates

Jorrit: Zillow’s algorithm accounts for physical characteristics and location of the home, but does not account for condition. This is one reason we include a value range below each Zestimate. This is also why we stress that Zillow is meant to be a starting point, and not the final word, on a home’s value. A real estate agent can provide a more refined estimate by also taking into account factors such as the condition of the home, its charm or curb appeal, as well as any local market nuances, such as a certain type of home being in higher demand for that particular area. Zillow is a great first step, but we always recommend an agent as that second step if you’re really serious about buying or selling.

“Can the data for a specific area be accessed to a web site by an RSS feed?”
-Matthew from Oldest City Realty

Jorrit: Currently, no – though that’s a great idea! It is, however, possible to integrate data from our local pages into other websites via the Zillow API. Our API returns data in raw XML format that is very flexible to work with. Partner sites can pull statistics such as median household income, the total number of households in the region, Zindex, Zestimate distribution, year built distribution, and home type. Drew from our community relations team has written previously about the types of local real estate data available and some possible uses for that data. Additionally, for those interested in neighborhood data specifically, we have neighborhood shape files available for 7,000 neighborhoods covering 150 US cities available for free and have seen some fantastic integrations as a result.

If you have any others questions, or feedback for how next quarter’s Webinar could go more smoothly, please feel free to comment on this post, or email them directly to us at