Zillow vs The Coyle Group Part III

The Coyle Group vs Zillow Part III

It’s that time again for the annual match up between Zillow and The Coyle Group.  This year we randomly selected 25 appraisals completed by our office with in the past 3 months.  The appraisals were of properties across Philadelphia, Montgomery County, Bucks County, Delaware County and Chester County.  Housing styles ranged from simple South Philly row homes to Center City condos (you’re welcome Mark) to Main Line mansions.

Below is a chart of the results.  The first column shows where the property is located, the second The Coyle Group’s appraised value and the third Zillow’s Zestimate.  The last column shows how high or low Zillow was relative to our appraised values.




 Zillow Zestimate


Rittenhouse Square Townhse  $    990,000.00    $     954,000.00


Chestnut Hill Twin  $    285,000.00    $     329,000.00


Ambler Colonial  $    570,000.00    $     396,000.00


Burholme Twin  $    125,000.00    $     138,000.00


Media Split Level  $    325,000.00    $     251,000.00


Mount Airy Twin  $    310,000.00    $     259,000.00


Northeast Philly Row  $    171,000.00    $     172,000.00


Hatboro Split Level  $    225,000.00    $     244,000.00


Gladwyne Colonial  $    600,000.00    $     758,000.00


Society Hill Townhouse 1  $    875,000.00    $     848,000.00


Conshohocken Single  $    190,000.00    $     252,000.00


Flourtown Colonial  $    735,000.00    $     698,000.00


West Chester Colonial  $  1,300,000.00    $  1,000,000.00


Society Hill Townhouse 2  $  2,100,000.00    $     922,000.00


Chestnut Hill Colonial  $    975,000.00    $     857,000.00


Bryn Mawr Colonial  $    770,000.00    $     750,000.00


Havertown Cape Cod  $    295,000.00    $     286,000.00


South Philly Row  $    186,000.00    $     151,000.00


Doylestown Colonial  $    395,000.00    $     337,000.00


Villanova Tudor  $  1,550,000.00    $  1,430,000.00


Roxborough Row  $    240,000.00    $     210,000.00


Warrington Colonial  $    435,000.00    $     378,000.00


Condo – The Philadelphian  $    675,000.00    $     634,000.00


Condo – Queen Village  $    180,000.00    $     183,000.00


Lafayette Hill Colonial  $    325,000.00    $     275,000.00



The results are pretty amazing.  In a few comparisons, Zillow was right on target.  For instance, I would say that they were spot-on with the Northeast Philly Row and the Queen Village Condo.  They were fairly close with number of others including the Rittenhouse Square Townhouse, Society Hill Townhouse 1, the Bryn Mawr Colonial and Havertown Cape.

However, Zillow completely whiffed on a number of others, most notably the Society Hill Townhouse 2.  Zillow wasn’t even close.  The Zestimate missed the mark by more than 127%.  That’s crazy considering there was a recorded sale of this property in 2013 for $1.85M.  This is where having a human being analyze the market data is so crucial.  All the fancy algorithms and computer models overlooked the simple fact that this property sold only months ago for twice the Zestimate amount.  We appraised the property a couple months after the sale and following a renovation of the kitchen and baths.

On average, including the Society Hill 2 property, the Zillow Zestimate was 23.42% lower than the appraised value.  Excluding the Society Hill 2 property, Zillow was still off by 16.47%.  When Zillow over-Zestimated they did so by 11.25%, on average.  These are some significant numbers.  If you were selling and used a Zestimate to potentially under-price your house, you could be leaving huge sums of money on the table.  If you overpriced, the market would likely pass you by in favor of more competitively priced homes.  Eventually, you would have to reduce your price and by that time many of the interested buyers will have moved on.

Philadelphia and the surrounding counties are such a patchwork of real estate markets that computers and algorithms can’t possibly take into account the individual nuances.  Zillow doesn’t take into consideration if there’s a vacant house next to your property or a golf course.  Zillow looks at them as being the same. That’s why having a knowledgeable appraiser to physically inspect the property is so important to realizing a correct value.  Nothing (so far) beats having a live human being appraising your property.

Bottom line, Zillow is not all bad.  It is not an appraisal but it is a good place to start.  The neighborhood data, general sales information, graphs and comparative tools are great and very user-friendly.  However, if you are looking to properly price your home, I would pass Zillow by and get some advice from a good local agent or a certified appraiser.

The Coyle Group’s team of Philadelphia appraisers are a leading provider of appraisals for Estate/Probate, Divorce, Bankruptcy, Tax Appeal and Pre-Listing appraisals.  If you need a guest speaker at your next sales meeting, please give us a call.  We would welcome to opportunity to speak to your group and field any appraisal related questions you may have.  For more information please visit our website at www.TheCoyleGroupLLC.com  You can also contact The Coyle Group at 215-836-5500 or appraisals@coyleappraisals.com



  1. Great article Michael! Anyone interested in the real estate market in your area should be subscribing to your blog with all the great information you share. Thanks for continually sharing such great information.

    • Roy, thanks for the compliment. I appreciate you following the blog from out there in Temecula, CA. Nice to have colleagues out there on the west coast.

  2. I love the blog post, I’ve done the same with Zillow in my area and seen similar results. The real problem with Zillow is not that algorithms cannot, the problem is that they do not have all the data. In our area, Zillow does not know basement area or finish. This is a big issue. Additionally, Zillow does not know condition, quality, or view. I too could not appraise a property if I was blind to all of these factors. The thing that scares me is that someone paid minimum wage can go out and collect data on the subject and comparables in a form that computers can understand (like C3 or Q4). The thing that scares me is that once computers have all of the information, they can be quite accurate. Computers like Zillow will change the face of appraising. The Bradford Comp Cruncher program can already take an inspection done by someone else and turn it into an appraisal in seconds (and something that the appraiser only makes a very small fee on). Things are chang!
    ing, I just hope that us appraisers will be able to find a way to make a living. http://www.aqualityappraisal.com

    • Hi Gary, thanks for following the blog. I can see your point. I like to look at it this way, access to better data and technology are getting better for appraisers, too. I know you take advantage of every available tecnology in your practice. That’s what separates you from the other Portland appraisal firms. The future of appraisal will go to those appraisers who can use technology and analyze data the best. If appraisers don’t embrace the advances that have been made available, they will go by the wayside…just like stick-on comp arrows, film cameras and graph paper.

      • I could not have said it better myself. That is why when any of my appraisal clients need appraisal services in the Philadelphia area, I send them to the Coyle Group. I know that they will be taken care of by real experts.

  3. Mark Malfara says:

    Nice job Coyle Group.

  4. Great article, very original. I have a keen eye for the obvious and the cost of an appraisal is nothing compared to the benefit. Can’t wait for the next one.

  5. Well done Mike. This article hits the nail on the head. If you can, please forward the article in a PDF format so I can pass it along to my realtor friends / business partners.
    Keep up the good work !!!


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