Which Report to Use

Zillow, Or… the “Accredited Valuation System” powered by Black Knight data?

Click Here to Sign Up to get an instant FREE Home Value Report

To get some insight, I asked ChatGPT: 

Q:  Why are Zillow home value estimates sometimes highly inaccurate?

A:  Zillow home value estimates, known as “Zestimates,” can be inaccurate for several reasons:

Limited Data Sources: Zillow relies on publicly available data and user-generated content to generate Zestimates. While they have access to a broad range of data, the accuracy and completeness of this data can vary. In some cases, critical information may be missing or outdated.

Lack of Local Context: Real estate markets are highly localized, and property values can vary significantly from one neighborhood to another. Zestimates may not adequately capture these local variations, leading to inaccuracies.

Market Fluctuations: Real estate markets are dynamic and can change rapidly. Zestimates may not always reflect the most current market conditions, causing estimates to lag behind or inaccurately reflect changes in property values.

Property-Specific Factors: Zestimates do not account for property-specific factors that can affect value, such as the condition of the home, recent renovations, or unique features. These variables can significantly impact a property’s value.

Data Errors: Errors in public records and data sources can lead to inaccuracies in Zestimates. These errors can include incorrect property details, tax assessments, and transaction histories.

Property Descriptions and Photos: The accuracy of property descriptions, photos, and details provided by homeowners or real estate agents can vary. Inaccurate or incomplete information can lead to inaccurate estimates.

Market Volatility: Rapid changes in local market conditions, such as shifts in supply and demand, can affect property values. Automated tools like Zestimates may struggle to keep up with these changes.

Data Accessibility: Zillow may not have access to all relevant data, especially data from private transactions or off-market sales. This can lead to incomplete information and inaccurate estimates.

Geographic Coverage: The accuracy of Zillow’s estimates can vary by location. In some areas, Zestimates may be more reliable due to the availability of comprehensive and up-to-date data, while in others, the estimates may be less accurate.

Algorithmic Estimation: Zillow’s estimates are generated using complex algorithms, and while these algorithms are sophisticated, they may not always accurately reflect the true market value of a property, especially when unique or complex factors are involved.

There are certainly accuracy issues involved with Zillow Zestimates, and much of it appears to be related to inaccuracy or errors in the input data they use.


I did some research and found out that Black Knight is the data service which warehouses and indexes the majority of the mortgage origination information in the United States including appraisals of the homes where loans were originated. 

These appraisals have verified the condition, living area, location, and quality of upgrades for the majority of the closed sales in the United States.  So, the Black Knight data is the most accurate available, and they do not share it with Zillow.


As it turns out, Black Knight has their own Home Valuation System. Lenders are the ones who share the data with Black Knight, so it is only natural that the lenders have been using Black Knight’s 3 independent accredited Automatic Valuation Models for many years when they need to quickly & accurately estimate the value of a property.

With a little extra digging, I learned Black Knight now has a Home Value Report system which realtors can offer to their family, friends, and clients… I just had to agree to pay their fee.  No problem, the fee has been paid.

I now offer an Automatic Home Valuation System (powered by Black Knight) which can send you a free Home Value Estimate each month which more accurate than Zillow.

Click Here if you would like to start your monthly report!

Even, if you’re not in the market to buy or sell, it’s nice to see an accurate estimate of the value of your home each month.

There are several popular features included in the report in addition to the 3 independent Home Values Estimates:

   > Recently sold properties in your neighborhood

   > The report will estimate of your home equity (enter loan balance at sign up, the system will calculate the pay down monthly)

   > A Heat Map will show the estimated number of buyers doing home search activity in your city and nearby

   > An overview will indicate an approximate number of buyers who are presently looking for a home like yours

Once you sign up, you will receive the monthly report shortly via email. If you would like to stop the monthly report – simply click “unsubscribe” at the bottom of the email.

Click Here if you would like to start your monthly report!