Zillow vs. a Real Appraisal: What Homeowners Need to Know in Phoenix
When it comes to home value in Phoenix, one number can look completely different depending on where you get it.
Hey everyone, I’m Diana with Benson Appraisals. A few weeks ago, I appraised a home in Mesa where the seller was convinced their property was worth $515,000 because Zillow said so.
My professional appraisal? $482,000.
That’s a $33,000 difference.
Two days later, I appraised another home where Zillow was $46,000 under the real value.
So why does this happen?
Let’s break it down.
What Is an AVM (Automated Valuation Model)?
An AVM is essentially a computer algorithm trying to estimate your home’s value based on:
Square footage
Age of the home
General location
Public and recorded data
Here’s the key issue:
An AVM never steps inside your home.
It doesn’t see your upgrades, verify your data, or study real-time market activity. It’s a starting point — not a valuation.
Why AVMs Fail in the Phoenix Market
Phoenix is one of the most complex real estate markets in the U.S., and here’s why Zillow and other AVMs routinely get values wrong:
1. Remodel Quality Varies Dramatically
Two homes built in 1995 can look like entirely different properties inside.
An AVM cannot distinguish between:
Original oak cabinets from the 90s
A modern remodel with shaker cabinets
A full kitchen renovation with new plumbing, layout, and finishes
Interior condition is invisible to algorithms.
2. Public Records Are Often Incorrect
As an appraiser, I see errors constantly:
Unpermitted additions
Enclosed patios
Casitas or guest houses
Wrong GLA (gross living area)
Incorrect bedroom or bathroom count
If the public data is wrong, the algorithm pulling from it will also be wrong.
3. Pools, RV Garages, Views & Lot Premiums Are Not “One-Size-Fits-All”
AVMs do not understand:
Pool quality
Age and condition
RV garage size
View corridors
Lot desirability
Neighborhood-specific premiums
These features can add tens of thousands in value depending on the area — something only an appraiser can properly analyze.
4. AVMs Can’t Judge Condition or Appeal
They don’t know if your home:
Is beautifully maintained
Needs $20,000 in updates
Has new flooring and fixtures
Has functional issues
Presents well in person
Condition is one of the biggest drivers of value — and computers can’t see it.
5. AVMs Can’t Interpret Supply & Demand
Appraisers analyze:
Active listings
Pending sales
Competing inventory
Absorption rates
Market shifts
Algorithms don’t track competition the way a human does.
How Appraisers Determine Accurate Value
When I perform an appraisal, I look at much more than square footage:
✔ Interior upgrades
✔ Quality of finishes
✔ Recent comparable sales
✔ Concessions and seller credits
✔ Supply & demand
✔ Active and pending listings
✔ Lot differences and views
✔ Functional issues
✔ Market trends
This results in a true market valuation, not a computer-generated approximation.
Real Example from the Field
I once appraised two homes in the same subdivision:
Same model
Same year built
Same square footage
One sold for $460,000.
The other sold for $525,000.
Why the $65,000 difference?
One was fully remodeled.
The other had original finishes from 2005.
Zillow treated them as identical — because an AVM can’t see updates.
When You Should NOT Rely on a Zestimate
There are times when “close enough” isn’t good enough.
Don’t rely on Zillow for:
Selling your home
Buying a home
Divorce cases
Estate planning
Probate
Disputes
Removing PMI
Cash purchases
Investment analysis
These situations require accuracy, not automated guesses.
Final Thoughts
Zillow is a great starting point, but it is not a valuation.
If you want to make confident decisions—especially in a complex market like Phoenix—get a professional appraisal.
At Benson Appraisals, we provide accurate, unbiased home valuations based on real market data and in-person analysis.
📩 Need to know your home’s true value? Contact us 480-926-8528 or email: [email protected].
