
Ask HN: Zillow and redfin estimates overtime, comparison? - sdsdsdsdsdsds
Hi,
Is anyone aware of a service&#x2F;website which shows how zillow and redfin estimates vary overtime(for a given address or region). Ideally,  I want a report which alerts me when zillow modifies my home estimates. More generally, what are some services for tracking accuracy of automated valuation models?
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gamblor956
Zillow is not accurate at all. In my market, Redfin has been accurate to
within 5% of the price, up or down. However, Redfin is a real estate agency,
so they use their estimates and have access to data that Zillow doesn't, and
they will adjust the algorithm at a neighborhood level.

Zillow is merely a real estate value estimator (they don't use sufficient data
to earn the right to call themselves an appraiser nor do they provide
sufficiently updated listings to justify calling them a listings service).

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BeetleB
With Zillow, you can just track a home (don't recall how - maybe just "Save"
will work?). You can have it periodically email you reports on the home, which
will include the value estimate.

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joezydeco
_Ideally, I want a report which alerts me when zillow modifies my home
estimates._

So sign up with Zillow and "claim" your home, then subscribe to email updates.
You'll get mailed weekly with your "estimate". Using quotes there because,
like gamblor956 says, the values are complete bullshit.

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mooreds
I am not aware of any services but they have an API. I think it'd be skirting
the tos to save it, but if this is just for personal use it might be ok.

[https://www.zillow.com/howto/api/HomeValuationAPIOverview.ht...](https://www.zillow.com/howto/api/HomeValuationAPIOverview.htm)

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mooreds
As far as general tracking of avms I don't know of any and the incentives are
not properly aligned to have them set up (avm provider doesn't want to show
inaccuracies).

Zillow used to show percentage error but it was a web page showing
inaccuracies by zip.

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sdsdsdsdsdsds
I agree with the incentives part. But, apparently, some AVMs(not necessarily
Zillow) are used by mortgage lenders to adjust their risk models. In such
cases, I would assume lenders will first want to find out information about
accuracy(through third parties).

You are right that zillow used to show accuracy by zip code. But I am looking
for more granular info.

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mooreds
Sure, I bet the AVMs share their accuracy to people that pay them, but I bet
not to folks who don't (consumers).

Anyway, hope this post turns up some useful info.

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itsdrewmiller
Zillow will give you monthly updates on their estimate of your house, and they
show a history of their estimate when you drill into a house. When I listed my
house for sale last month their estimate shot up immediately to closely match
the offer price, so worth being skeptical.

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bsvalley
You could build a simple web crawling tool pointing to the URL of your house
on zillow or redfin (trigger it just once a day).

Zillow estimate is way off by the way...

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chrisgoman
How much are you willing to pay? Are you expecting this to be a free service?
There is a company called Altos Research

