Head Explosion

Zillow just increased the condo’s value by $7k in one day.

Screen Shot 2016-06-08 at 2.05.47 PM.png

Just in the last 30 days they’ve bumped up the value by $20k

Screen Shot 2016-06-08 at 2.07.45 PM.png

This makes me believe they may have a bug in their predictive algorithm.  They should have controls to match actual sales prices vs. predicted value., so this just baffles me.

San Francisco, CA 1.3M 1.2M 36.0% 60.6% 82.7% 7.6%

Area, accuracy, homes, homes with zestimate, 5%, 10% 20% median error rate 7.6%.

so 36% sell within 5%

60.6% sell within 10%

82.7% sell within 20%.

20% is pretty damn big though.  For $400k, that’s +/- $80k.

Meanwhile, Redfin still says $349,075 and claims to have the “lowest published error rate of any home-value estimate.”


Still not bad.  If I take the Redfin value as true, that means the Zillow value is off by +14.49%

[address] is a condo in San Jose, CA. This 784 square foot condo features 1 bedroom and 1 bathroom. This property was built in 1984 and last sold for $153,000. Based on Redfin’s San Jose data, we estimate the home’s value is now $349,075, which is 128.2% more than when it was last sold. Comparable nearby homes include 1525 Alma Ter, 573 Shadow Dance Dr, and 510 Shadowgraph Dr. Nearby schools include Hammer Montessori at Galarza Elementary School, Ernesto Galarza Elementary School and Willow Glen Elementary School. The closest grocery stores are Fresh & Easy Neighborhood Market (lol sad, is closed… Safeway soon though!), Willow Glen Way Market and Mother Daughter & Son Mini Market. Nearby coffee shops include Starbucks, Willow Glen Coffee Roasting Company (closed?) and Le Boulanger Inc.. Nearby restaurants include Agave Sports Bar & Grill, Souvlaki Greek Skewers and Bibo’s NY Pizza. [address] is near River Glen Park, Hummingbird Park and Biebrach Park. There are excellent bike lanes and the terrain is flat as a pancake. [address] is very bikeable, biking is convenient for most trips.
The Redfin Estimate has the lowest published error rate of any valuation estimate in the U.S., with only a 1.93 percent median error rate for homes that are for sale, and 6.10percent for off-market homes. This means that when a home that is currently on the market sells, the Redfin Estimate will be within 1.93 percent of the sales price half of the time. For off-market homes, the Redfin Estimate will be within 6.10 percent of the eventual sales price half the time. The Redfin Estimate is more accurate for homes that are for sale because there is more data available about those homes.
But LOL LOL Redfin’s estimate of the identical condo right next to mine is $427.5k.  There is no significant difference between the two.  Zillow’s estimate is within $1k.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s