Zillow's a lot of fun, but it's not very reliable. To determine the value of a house, ask a Realtor for a CMA. Or, if there's a real reason for it, pay an appraiser to do an appraisal. (The Realtor won't charge.)
There was a similar question posted a week or two ago, regarding a property in Colorado. Here's my response to that question. I've also done a similar test for properties in Virginia. I'm confident that I could duplicate Zillow's performance in most areas of the country.
Here's my recent Zillow post:
No. Zillow isn't particularly reliable for any market.
If you think that Zillow provides consistently reliable estimates of a property's value, then do a couple of Zestimates. I can randomly select a typical property in a typical neighborhood and most of the so-called "comps" aren't comps at all. Let's try it. You game?
I plugged in "89449" in Zillow to bring up some homes in Zip code. I came up with one on 138 Daggett Way. It's a 3 bed/2 bath single family home built in 1956. It's on the market for $399,000. That's what we'd call a "bread and butter" home--nothing fancy, but OK. The description says it does need some work: "A great price for this 3 bedroom 2 bathroom home with 1,512 sq ft of living space & almost 1/3 acre mostly flat & sunny.This is a perfect project for a contractor or handyman. This property has deferred maintenance and needs upgrades but the possibilities are endless for this Lower Kingsbury home."
First odd thing is that the Zestimate for that house is $574,000. Might actually be a good deal...if the Zestimate is accurate. So, let's look at Zillow's "comps."
Well, there's 1521 Bonita--a 3/2 built in 1970. Not too far off. But Zillow says it sold for $125,000. Sounds a bit low. Can you really buy that sort of home for $125,000? If so, then even the list price on Daggett is too high. But let's continue.
Another comp: 4081 Greenwood. It's a 5 bed/3 bath built in 2007. Now, I wouldn't call that a comp to a 3/2 built in 1956. It sold for $1.3 million.
Another comp: 4027 Crest. It's also a 5/3. This one was built in 1977. Again, not what I'd call a comp. It sold in December for $845,000.
Another comp: 395 Sherwood. Zillow doesn't have the number of beds and baths. And it was built in 1978. Not a great comp, since we don't know beds or baths, and it's 22 years newer. That one sold for $980,000 in January.
Most of the other comps are just as, well, incomparable.