More homes and Zestimates everyday
By: Stan Humphries, VP, Data & Analytics | April 13, 2006
Great idea from David Porter about keeping folks abreast of updates in our data coverage as we build out our beta site. We currently have approximately 65,241,670 homes on Zillow.com which is up 5% from the roughly 62M homes that we had at Zillow’s beta launch in February. Most of these additions are homes already in existing coverage areas for Zillow, but are either new construction or existing homes that we are just now finding.
The number of homes for which we can create a Zestimate has also increased from 40,967,771 homes at launch to 47,464,478 homes currently (a whopping 16% increase!). The number of homes for which we can create Zestimates has increased more than the number of homes covered because of some new approaches that we have used to Zestimate in areas in which we previously could not. Since launch, we have started to Zestimate in six additional counties: all five counties in Rhode Island and Anderson County, TN.
As some of you may have noticed (Chris L certainly did), at launch we made lots of folks in Utah and Wyoming fabulously happy with homes prices that were, erroneously I’m sad to say, quite a bit higher than they should have been. Homes in these states are somewhat trickier to Zestimate because of the scarcity of sale price data. That said, we went back to the drawing board and now have what we believe are better Zestimates in these two states. If you live in the five counties in Utah or Wyoming that we cover (Salt Lake, Utah, Weber, Davis, and Natrona), please tell us what you think.
On the analytic front, today we introduced a few algorithm changes designed to make My Zestimator more accurate and eliminate some of the occasional counter-intuitive behavior that users encountered when making changes to homes facts (e.g., adding an additional bedroom and the value of the home decreasing). The user feedback that we have received thus far about My Zestimator has been incredibly helpful in our efforts at making this tool even better, so check out the newly improved tool and let us know how you find it.
Two months out of the gate and we’re working hard to cover more areas, add more data and Zestimate more accurately. Thanks for your continued feedback.
- Stumble it!
- Categories: Zestimate, Zillow
Comments
23 Comments so far
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David Porter on April 14, 2006 5:59 am
Thanks! Keep up the good work.
davidagius on April 14, 2006 7:09 am
Why cant you provide a sale price ,market price ? do you plan to in the future ?
Thank you ,
Dave
Luke Gunderson on April 14, 2006 9:10 am
I live in Salem, Ut just south of Provo.
When I first Zestimated my house is way about $790,000 (crazy high). I checked it two weeks later and it was $78,000(that would be a steal) Now it’s around $190,000(right on the money). Good job zillower!
Stan Humphries on April 14, 2006 9:26 am
David: Thank you for the suggestion!
Dave: Could you elaborate a bit on your question? In areas in which we have sale prices, we do provide both a Zestimate and show sale prices on homes. Are you asking for something different or asking about Zestimates in a specific area?
Luke: Great to hear that you’re finding the Zestimates on the mark in your area. Thanks for the feedback. By the way, the $79K figure was likely a tax assessment, not a Zestimate. We switched to showing tax assessments in those areas while we corrected the valuation models.
Matt Borthwick on April 14, 2006 10:12 am
Why give only a single value for the Zestimate?
Why not emphasize your Value Range statistic more? (Is that a 95% confidence Zinterval?)
This would reduce a lot of the critics’ complaints about missing the exact sale price of a single home, and give users a much clearer sense of how precise a particular Zestimate is.
Better yet, give all three values: the Zmedian *and* the CI on the main page.
Pete on April 14, 2006 8:42 pm
Tried finding my home on your web site, but it says Zillow can’t find that address. House has been here for almost 6 years. Not a lot of help!
Guess I’ll find a Realtor to help me!
Pete
HM on April 15, 2006 3:09 pm
amazing job with the site. As a home-shopper I am a BIG fan.
Keith on April 17, 2006 5:33 am
How does Zillow determine the “construction quality” value? My house is listed as a 4. It’s brand new, and the homes around mine are listed as a 6. How is this number determined? Where does this info come from? What factors can determine the difference?
David Gibbons on April 17, 2006 11:24 am
Keith;
This value for “construction quality” is provided by the assessor’s office in local jurisdictions. Assessors give homes a rating from 1-10, with 1 being poorest quality and 10 the best. This value is their assessment of how well the building was constructed.
Homes are rated relative to each other within a county; therefore, one county’s value might not correlate to another county.
James on April 17, 2006 11:38 am
First off, I’m not sure this is such a great service if you are selling your home. Someone’s going to have to explain to me just who makes it your business to tell me what my home should sell for. There’s just too many different factors involved to say what a home is worth. I know there is a “range” involved with every parcel listed on this site, but when someone is looking to buy a home, they’d be more inclined to lowball the homeowner based on what they see as the $ amount listed on the property. And I guess that’s good for the buyer and not so good for the homeowner/agent. I just don’t see how someone selling their home, especially now as the market leans towards a buyers market could possibly get full value. Let’s say the owner is selling to reap the benefits of his/her lifelong investment and retire with the proceeds. I’d sure want to bank all that I could, and not be lowballed out of $15-$25,000 because some web page says that’s all my home is worth. THIS IS NOT GOSPEL FOLKS. My subdivision is listed on this site and the neighbor to the west of me has his house on the market. He’s asking more than is listed on his mousover. I plan to stay in my home for a while. I can only hope that the value continues to increase.
Stan Humphries on April 17, 2006 10:16 pm
Matt: Interesting ideas. While I think showing only the confidence interval would lessen some criticism, I think users find value in a point estimate that represents our best estimate of the value combined with a range within which we are fairly certain the actual value is located. And, you’re exactly right that the current Value Range is useful for understanding our level of confidence in a specific Zestimate. We are also working on ways to make the Value Range even more helpful in understanding a given house and how it relates to the overall market.
Pete: Do you mind emailing me directly the address you’re having difficulty locating? Might help uncover some issue that we don’t yet know about. Thanks in advance.
A.G. Stern on April 22, 2006 12:02 pm
I think this could be a really useful service. But you really need to button up your information.
You also need to have some mechanism that allows you to correct information that has been
sent to you by the homeowner.
It is not fair to the buyer or seller to project prices based on wrong information. For example I
have been trying to change the number of bedrooms listed on my home. I have sent over 5 emails,
reponses none and the listing is not corrected.
Cory on April 22, 2006 5:17 pm
Zestimates is a zucking zoke!
Of my 3 properties, the zestimates were +20%, (-30%) and (-10%).
Great concept, worthless result.
David Gibbons on April 26, 2006 6:09 pm
A.G Stern: David from Zillow here. Thank you for your feedback.
We agree that some homeowners have more current information about their house than what we have received from the data providers who collect and aggregate these public records. Yours is actually the most common request we’ve received from Zillow users, so we’ve made it our first priority. Homeowners will soon be able to permanently edit their home facts on Zillow.com. To be notified when this feature becomes available, you can sign up by selecting “notify me when I can edit my home facts” on our feedback form (click “give feedback” at the bottom of any page).
Lastly, my apologies that we haven’t responded to your prior feedback. We read every comment sent by our users but during this beta phase, have not staffed up to reply to most users’ comments. I am personally working on launching customer service and can guarantee you that you will soon have a more responsive channel for contacting us.
Thank you for your feedback.
Steve Bastasini on May 16, 2006 9:59 am
your zestimates are WAY off base -
in redwood city, ca. you have a home, 711 edgewood rd, zestimated at $1.9m, the home is listed in the mls for $3.5m
I’d say $1.6m is a BIG difference - you should do your homework on comps before you post data
This is not hard work, just time consuming - get it together people.
SB
scott on May 18, 2006 6:44 pm
i keep waiting and waiting but zillow still doesnt list my home or my neighbors home value on ur site. its been around 6 months since we moved in(new construction on both). i’ve emailed u countless times with no response…..wtf???
zip code 92386(california)
scott on May 18, 2006 6:47 pm
u have a home (251 riverside, zip code 92386)listed at approx. $285,000….its on the MLS for $345,000 and is getting seen by prospective buyers….
way off???
scott on May 18, 2006 6:49 pm
680 Orange ave. 92386
629 Orange ave. 92386
still waiting for u to add these homes to ur site…..its been 6 months since they were built….
David Gibbons on May 19, 2006 12:40 pm
Hey Scott, its David from Zillow here. If only it were that easy!
We appreciate your feedback and you’re not alone; a couple of hundred folk write us each week because their home is not yet “searchable” on Zillow.com. If you checked our data coverage report (http://www.zillow.com/howto/DataCoverageZestimateAccuracy.htm) you’d have noticed that we’re doing better in CA than elsewhere, but we still don’t know about 15% of the homes.
We launched Zillow.com with 62M houses and have added more than 3M since February. It’s an ongoing exercise with high priority. We’ve blogged about this quite a lot; browse our archives for more details on this process.
The houses you’re interested in are (luckily) examples of the best case of our various “unknown property” scenarios. We have the neighborhood info required to locate the property and to calculate the Zestimate; so these homes will be easy to add when we’re informed by our data providers that the properties have been added to the public record in San Bernadino.
We know this process has a lengthy lead time for new houses. We will work on reducing it.
In the meantime, you can get a VERY good idea of local Zestimates by browsing the neighborhood for similar homes; and reviewing the comps we’ve picked for them. Click ing through to neighboring homes’ details and picking a nearby home with a very similar tax assessment is another good approach.
Lastly, I’ll be answering the question about Zestimate accuracy in a detailed post by Monday; please check back to learn about how to use the Value Range we publish to better understand Zesimate accuracy.
Have a great weekend.
scott on May 22, 2006 5:01 pm
David..
thank u 4 finally getting back to me….the problem with comparing my home to others in the area as u suggested is>>>
98% of the homes built here were built years ago and are very small. they are only in the $200k range, my home is twice the size and is much newer than 98% of them. how can i do comps when there is nothing like my home in the area to comp.. i cant comp 100’s of 1-2 bedroom homes built 20 years ago(that are approx. 900 sq. ft.) to a new home with granite, stainless, and twice the sq. footage.
in some towns across the country all the homes are very similar and were built around the same period. that is not the case here(in a mountain resort community). my home as well as 1 neighbors home are drastically different than the others in this town. i guess i just need to wait for zillow to acquire the appropriate info….
Dearmad on July 21, 2006 2:47 pm
Scott, you are an idiot with too much money.
Houses are not valued by square footage and marble plating (your floors are not solid marble, it’s a thin veneer over concrete at best, idiot- maybe even wood).
NEW <> good quality, in fact unless you were involved with the architectural planning and construction of the house, I bet $$ you have NO CLUE what your house’s true construction quality is. In 20 years will YOUR house still be standing along with the now 40 year old WELL BUILT houses you lord over in your little rat kingdom?
g. wilson on August 10, 2006 2:01 pm
Hello. I’m quite frustrated that Zillow has our house listed with the wrong number of bedrooms, the wrong square footage, and the wrong date for last remodel/update by THIRTY YEARS. The remodel included a state of the art kitchen, over 30 skylights, oversized master suite, cherry wood floors, granite, full tile and glass bathrooms, lots of large windows and french doors, high ceilings, dining room with seating for 30, a great room, and parklike landscaping. Everything was done by a noted architect/designer. We have one of the most sought after properties in our neighborhood, yet its zestimate is one of the lowest because of the misinformation. I understand that we will soon be able to put in our own information for corrections, but will that change the zestimate? Errors like these could impact negotiations on a future sale.
Mark on September 15, 2006 10:47 pm
Hey, I just bought a house and am officially addicted to the site, awesome stuff here. Was wondering when the next Zestimate update would be though? I’ve been clicking my neighbrohood for weeks but the newest sales info I can find is over 3 weeks old.
Btw, I have an idea that would be really cool (and save me a butt-load of click-time): A special type of search that displays inflation-adjusted SOLD prices of homes instead of Zestimates… It would have to be implemented like this though to keep it simple:
1) In advanced search, a radio button would be needed to toggle between displaying Zestimates or Inflation-adjusted sales prices
2) The radio button would only become enabled if the “Sold Within” date was set to “no date”
3) After the search, the map would display the selected value (Zestimate or Inflation-adjusted sales price) for the selected date range
4) Also, the result set table would only show a value column for what was selected
This might take away from the Zestimate a bit but for people that are seriously about to buy a home or just bought a home (i.e. me, hehe), we care more about what the house actually sold for than what the estimate is.
Thanks,
Mark.