Your Staten Island Zillow Estimate Is Wrong. Here’s What to Trust Instead.

Every seller does the same thing before they call a Realtor.

They look up their Zestimate.

They look at the big number. They anchor to it. They decide what their home is “worth” based on it.

Then I walk through, run real adjusted comps, and the real number is $30,000 to $80,000 off the Zestimate. Sometimes high, sometimes low. Almost never exactly right.

Let me explain why your Zillow Zestimate is wrong, how wrong it typically is, and what to trust instead.

I am Allison Mireau with Real Connect Group.

What the Zestimate actually is

Zillow says the Zestimate is a starting point. Not an appraisal. Not a market value. Not a listing recommendation.

The way it works:

• Pulls public records data (last sale price, square footage, bed/bath count, lot size)

• Applies a national algorithm to estimate current value

• Updates based on nearby closed sales

• Factors in some market trend data

• Spits out a number

That is the entire methodology. No one walked through your home. No one looked at your kitchen. No one knows if your basement is finished or flooded. No one knows if you added a bathroom in 2022 that was never permitted and never recorded.

The number is a guess based on data. Smart data, but guessed data.

Zillow’s own accuracy numbers

Zillow publishes their own accuracy stats. Here is what they say.

• Median error rate for on-market homes: around 2 to 3 percent nationally per Zillow’s published Zestimate accuracy data

• Median error rate for off-market homes: around 7 percent nationally

• “Within 5 percent” accuracy: around 80 percent of on-market homes

• “Within 5 percent” accuracy for off-market: around 60 percent

Translation. On a $750,000 home, Zillow’s own data says the Zestimate could reasonably be $50,000 off before you listed. After you list, it tightens to within $15,000 to $25,000. Before listing, when you need it most, it is the loosest.

Source: Zillow’s Zestimate accuracy page at zillow.com/z/zestimate.

Why the Zestimate misses the Staten Island market specifically

Staten Island has characteristics that trip up algorithmic valuations more than most markets.

1. Attached, semi-detached, detached inventory in the same neighborhood

• Zillow struggles to differentiate correctly

• Comparable square footage, wildly different value

• Can swing $100,000 or more in valuation

2. Older housing stock with wide variation in condition

• Two homes with the same bones can sell $150,000 apart

• Zillow sees square footage, not condition

• The dated 1960s original kitchen looks the same as the fully renovated one in the algorithm

3. Lot size variation on compact urban lots

• Flat vs sloped

• Corner vs mid-block

• Shared vs private driveway

• Zillow sees lot square footage, not usability

4. School zone and specific-block premiums

• Buyers pay $30,000 more for the right side of the same street

• Zillow does not know which side of the street is in the better zone

• School-boundary premiums get missed

5. Open permits and legal issues

• Open permits do not show in Zillow’s data

• Unpermitted additions do not show

• Legal issues that will affect sale price do not show

• Buyers will discover these; Zillow never did

6. Flood zone premiums and penalties

• SI has specific flood-zone pricing effects

• Zillow does not model this with precision

• Can be $50,000 or more off in flood-sensitive areas

7. The two-family vs single-family question

• Legal two-family vs legal single-family has huge value implications

• CO status matters

• Zillow often misclassifies

Any one of these can throw the Zestimate off by $20,000 to $80,000. Multiple at once, and the Zestimate becomes nearly useless.

The specific SI patterns where Zillow is reliably wrong

Here are the Zestimate errors I see most often on SI.

Pattern 1: Underestimated renovated homes

• Zillow does not know you spent $90,000 on the kitchen and bath

• Zestimate reflects the home as it was in public records

• Can be $40,000 to $100,000 low

Pattern 2: Overestimated dated homes

• Zillow sees square footage and comps to renovated homes

• Does not know your kitchen is original 1972

• Can be $30,000 to $80,000 high

Pattern 3: Overestimated homes with major deferred maintenance

• Zillow does not see your 25-year-old roof

• Does not see the water-damaged basement

• Does not see the HVAC on its last legs

• Can be $25,000 to $75,000 high

Pattern 4: Underestimated homes on premium lots

• Zillow sees lot size, not usability

• Flat large lots at a premium are often undervalued

• Can be $20,000 to $50,000 low

Pattern 5: Overestimated homes near problem comps

• Nearby sale at inflated price pulls the algorithm up

• Even if that sale was an anomaly

• Especially bad when a renovated flip sells high nearby

Pattern 6: Overestimated homes in zones that recently saw a hot spike

• Algorithm catches the spike and projects forward

• Markets normalize; algorithm lags

• Zestimate stays high while actual market cools

None of these patterns are unique to SI, but SI has characteristics that amplify them.

What the Zestimate cannot do

Let me list what the Zestimate does not know about your home.

• Whether the kitchen is renovated or original

• Whether the basement is finished, usable, or flooded

• Whether the roof is 2 years old or 25 years old

• Whether the HVAC was replaced in 2023 or 1998

• Whether you added a bathroom without a permit

• Whether the backyard is flat and usable or sloped and unusable

• Whether the garage is attached or detached

• Whether there is an open permit from 2017 you never closed

• Whether the house has had water intrusion

• Whether the lot has flood zone implications

• Whether the attic is finished

• Whether there is a legal two-family CO or just history as one

• Whether you have hardwood floors or worn carpet

• Whether the layout actually works for buyers

• Whether the showings generate second showings

• Whether the price point matches the hot demand range

That is 15+ things that materially affect sale price. None of which Zillow can see.

What to trust instead

Real market value comes from an adjusted comp analysis done by someone who walked the home.

Step 1: Pull 3 to 6 sold comps from the last 90 days

• Same submarket

• Similar size

• Similar vintage

• Normal arm’s-length transactions

Step 2: Walk the home

• Interior room by room

• Exterior and lot

• Basement, attic, systems

• Documentation review

Step 3: Adjust each comp individually

• Up or down for condition

• Up or down for size

• Up or down for lot

• Up or down for location

• Up or down for timing (how recent)

• Up or down for concessions in the deal

Step 4: Build the adjusted range

• Usually a 5 to 10 percent spread

• Honest market value sits inside the range

• Not a single number

Step 5: Check active competition

• Who else is for sale right now

• Where buyers are comparing you

• What inventory looks like in your range

Step 6: Factor pending data

• Directional information on where the market is moving

• Not confirmed until closed

• Weighted but not definitive

Step 7: Set the strategic price

• Inside the adjusted range

• Positioned to invite two serious buyers in the first 14 days

• Based on market data, not aspiration

This is a comp analysis. A Zestimate is not a comp analysis. Not even close.

What a Realtor should bring to the pricing conversation

• Verified recent sales with specific terms

• Walked-through-personally knowledge of comp homes when possible

• Adjustments for condition, size, lot, location, timing

• Pending sales data for direction

• Current active competition analysis

• Honest range with reasoning

• Strategic pricing recommendation inside that range

If the Realtor’s CMA is a one-page printout with Zestimate highlighted, you got a Zestimate, not a comp analysis.

The Realtors who use the Zestimate are also wrong

Yes, some Realtors use the Zestimate as a shortcut. They should not.

• The Zestimate is a starting point for a conversation

• Not a basis for a listing recommendation

• Not a replacement for a real adjusted comp analysis

• Not a professional valuation

If a Realtor hands you the Zestimate as the reason for a list price, you are getting lazy work.

When Zillow is actually useful

Not all Zillow data is bad. Some of it is genuinely helpful.

• Comparable sold data in a specific area

• Days on market history for competing homes

• Price reduction tracking for competing homes

• Buyer-side demand signals (saved listings, view counts)

• Historical sold data on specific properties

Use Zillow as a research tool. Just not as a valuation tool.

When Zillow accidentally lands close

Sometimes the Zestimate is actually in the right range. When does this happen?

• Cookie-cutter homes in cookie-cutter neighborhoods (less variation to miss)

• Recently sold comparable homes next door (lots of fresh data)

• Homes without renovations or deferred maintenance (fewer condition variables)

• Flat, standard lots (fewer lot variables)

• Current market conditions matching the algorithm assumptions (less lag)

Even in these cases, Zillow is a starting point, not a verdict. The Realtor’s walkthrough still matters.

What this means for your pre-listing decision

Before you anchor your pricing to the Zestimate, remember:

• Zillow has not walked your home

• Zillow does not know your condition

• Zillow does not know your renovations

• Zillow does not know your lot

• Zillow does not know your deferred maintenance

• Zillow does not know your open permits

• Zillow does not know your submarket nuance

• Zillow does not know the current buyer demand pattern

• Zillow is wrong by an average of 2 to 7 percent on its own numbers

$30,000 to $80,000 on either side. On a $750,000 home. That is the real variance range.

Anchoring your pricing to the Zestimate is anchoring to a guess. The guess might be close. It might also cost you $50,000.

What I will not pretend to advise on

I am not an appraiser. For formal appraisals, work with a licensed appraiser. For specific property tax assessment questions, work with your attorney or tax grievance firm. I can refer trusted ones on both sides of the bridge.

All of our work follows the Fair Housing Act, RESPA, the NAR Code of Ethics, and the real estate commission guidelines for New York and New Jersey.

Before you trust the big number

Ask yourself:

• Did Zillow walk through my home?

• Did Zillow see my renovations?

• Did Zillow see my condition?

• Did Zillow see my lot?

• Did Zillow see my permits?

• Did Zillow see my deferred maintenance?

No, no, no, no, no, and no. None of that goes into the Zestimate. All of it affects your real sale price.

Use Zillow for research. Use a real adjusted comp analysis for pricing. The sellers who understand the difference walk away with the right number. The ones who do not walk away with a Zestimate and $40,000 less than they should have.

Have questions about selling your home or relocating? Reach out to Allison today.

Call: 646.266.0188
Email: [email protected]
Website: www.statenislandtonewjersey.com

Contact Allison today to sell your home in SI.