How accurate is zillow.com for checking real estate prices?
With regard to actual sales prices, which are taken from public records? Or with regard to estimated values? The former, quite accurate, being actual numbers from real transactions, the latter, not so much, being an estimate based on some algorithm that may or may not have an actual bearing on reality.
I have had two assessments in the last five years (one to remove PMI, one for a refinance). Granted, I’m not taking these kind of assessments as ground truth for the value of the property, but both of them were within about 5% of Zillow’s estimate, one slightly higher and the other slightly lower.
Zillow is pretty accurate in terms of estimates as long as the house still matches the condition of its last sale. Zillow has no way to know about kitchen remodels, additions to the back or other improvements that might dramatically affect the sales price. Likewise, they also don’t have any way to know if the roof is leaking, the foundation is cracking or the septic needs replacing.
You also have to make sure that Zillow has the right information. It isn’t always accurate in terms of square footage, number of bedrooms or other significant details.
So, I consider Zillow a good enough resource that I use it for fair market value estimates on tax returns (where I can also ask the client about improvement or damage). I would not consider it good enough for purchase or refinance decisions.
For my own home, I would consider the accuracy marginal. It listed it as a 3BR home last sold in 2000. I did indeed buy it in 2000, but it has always been a 4BR home and appears on our tax assessment as such.
Since it shows us as a BR short, it is probably short-changing our current value significantly (it’s ZValue is about 17% below our last professional appraisal last year). On the other extreme, though, is its 5-year value graph which showed our home value peaked at 14% more than any sane person would have ever paid for it, even during the boom.
I did like the way it shows the property boundaries (or close thereto) when moused over. Our property is rather irregular, and it did a good job of showing the layout.
That’s odd–I thought that Zillow pulled that kind of information from a tax-assessment database. I wonder if Zillow is pulling info from Lexis-Nexis/Accurint’s databases, and it was Lexis-Nexis that had it wrong.
As someone who uses Zillow every day (or at least did until the research part of my job declined a bit), I always felt that Zillow was slightly on the high side for market valuations over the past few years. My colleagues in research agreed with that, although I have to say we don’t have any solid evidence to prove that. I suppose it might be because, since Zillow uses previous sales as a benchmark, if house prices are going down there’s always going to be a bit of a lag if Zillow is using months-old sale prices to identify current valuations. Plus, there’s always a bit of the Winner’s Curse at work with the old sales price data. I have no idea what alogrithm Zillow uses, so I’m not sure how much those old sales data affect Zillow’s current valuations.
In some markets, VERY accurate. In other, wildly inaccurate. How do you know which is which? Good question.
If you are seriously using Zillow to estimate property value, you need to cross reference it with other sources, and compare its historical “Zestimate” data with actual sales prices. In doing so, you can see if it’s accurate or if you need calculate a “correction” coefficent.
Also, remember, they say that in most cases, their “Zestimate” is within 10% of the actual value.
For my area, I would say (unfortunately 
) that Zillow is pretty damn accurate, to within 5%. It used to be way too high, but about 2 years ago they re-did their algorithm and their estimates came way down. There was a lot of bitching about it, but from what I saw most of the bitchers had wildly inflated views of their home’s value.
I use Zillow to keep track of trends, not so much absolute numbers - is my homes (and neighborhoods) value going up, down, or trending stable, rather than “How much is it worth RIGHT NOW”
Zillow had my house at 1 bedroom instead of 3 when I moved in.
That might partly be due to the previous owners. They decided to “save money” by listing the home for sale by owner. They screwed up their MLS listing in at least three places (including the wrong county, and they counted one room as a bedroom and counted it again as a bonus room). In fact, my real estate agent wound up becoming their real estate agent just to make sure the deal was closed right.
The house is in Clairemont (San Diego). We have no plans to sell it (though it would certainly make my life easier). I’d just like to keep an eye on the estimated value.
And it’s interesting to look at the house I live in. Zillow’s estimate puts it at 63.5% more than what I paid for it in 2003.
I live in a tract home. The houses are almost 50 years old but they’re still all pretty much the same. There is up to a 20% variance among the houses around mine where there should all be within no more than 5% different.
I have two houses and checked both at Zillow.
The one I live in is listed at 1200 sq feet, when I bought it it was 1540 and now it is 2100, and it is on an oversized lot. Sillow has it’s value normally about 1/2 of what it is. They list it for less than the small single story on a small lot.
the second one last time I look they has it listed as having sold for $310,000 in Janurary. I paid $250,000 in March and it had been on the market for 6 months.
So my SWAG on Zillow is they are using the SWAG system.
I just checked for 1 and 2 bedroom apartments in my neighborhood and it shows one listed for 2.6 million and another listed for less than 5K. Obviously they use some sort of automated system that isn’t real good and checking errors.
When I first looked up my house on Zillow, I discovered that they had somehow confused my property with the right-of-way of the private road next to me. The net effect was that they had my property as being 40 feet wide and a tenth of an acre (instead of 200 feet wide and a half-acre). I promptly adjusted that information as the property owner and while I was at it adjusted the size and number of rooms of the house.
I probably got the size of the house wrong, because ever since Zillow has declared the value of my property to be roughly 20% higher than every other property on the block.
I’ve never fixed that, because my property isn’t for sale - and if it was, pay the extra money, suckers!!!