What is my home worth, and why the online estimate disagrees

There are three numbers people mean when they ask what a house is worth, and they are not interchangeable.

An automated estimate is a model’s guess from public records and past sales. An agent’s opinion of value, sometimes called a comparative market analysis, is a researched estimate of what the property would sell for in current conditions. An appraisal is a licensed appraiser’s formal opinion, usually ordered by a lender to decide how much it will lend.

All three can land in different places on the same house. Understanding why tells you which one to rely on.

Where automated estimates are decent

In a large subdivision of similar homes built around the same time, with plenty of recent sales, the models do reasonably well. There is enough data, the houses are genuinely comparable, and there are few variables to miss.

That describes some of North Alabama. It describes very little of Connecticut.

Where they drift

The models work from what is recorded. Anything not in a public record is invisible to them, and anything specific to your property is hard for them to weigh.

Water and views. A view is worth real money and it is not in the assessor’s file. Two houses on the same street can be far apart in value because one looks at the water and one looks at the house that looks at the water.

Flood exposure. A model may know the address. It does not price what the flood insurance costs, and on the shoreline that is a monthly number a buyer subtracts from what they can pay.

Septic and well versus public utilities. This affects value, affects the buyer pool, and affects what a lender requires. Models rarely capture it.

Leased solar. This one costs sellers money regularly. Owned panels can add value. A leased system is a contract the buyer has to assume or the seller has to buy out, and it can narrow your buyer pool considerably. Most automated estimates treat any solar as a plus or ignore it entirely.

Renovations nobody recorded. If the kitchen was redone without a permit pulled, the model does not know. Neither does the assessor.

Condition. No algorithm has walked through the house. A well-kept home and a tired one with identical square footage and an identical build year look the same in the data.

Lots and location at street level. A busy road, a shared driveway, a steep or unusable lot, power lines, or simply the difference between two streets a map treats as one neighborhood.

The low-data problem

The bigger driver of error is thin data. When there are few genuinely comparable recent sales nearby, the model reaches further out, both geographically and in time, and the estimate drifts.

This is common in Connecticut, where inventory has been limited and many neighborhoods have varied housing stock. I have seen automated estimates land well over $80,000 away from where a property actually sold, in both directions.

That last part matters. People assume the error runs low. It runs high just as often, and a high estimate is more expensive, because it becomes the anchor for a list price the market will not support. The listing sits, the price gets cut, and you end up below where a correct launch price would have landed.

What a proper valuation does

Selects real comparables. Recent, nearby, and genuinely similar in size, age, style and condition. Three good comparables beat twelve loose ones.

Adjusts them. A comparable with a finished basement and yours without is not the same house, and the difference has a number attached.

Reads the competition. Closed sales tell you what buyers paid. Active listings tell you what your house will be shown against. Pending sales tell you what buyers have agreed to more recently than the closed data reflects.

Accounts for condition. Which requires seeing the property.

Explains itself. If someone gives you a number and cannot walk you through how they got there, the number is not usable. You cannot price a house against a figure you cannot defend, and you certainly cannot hold a price during negotiation with one.

What to do with the number

If you are selling, a researched value gives you a launch price and a floor. The launch price matters more than any later adjustment, because the opening days bring the most attention and a reduction in week six does not bring those buyers back.

If you are refinancing or making a decision about whether a move makes sense, you mostly need a reliable range rather than a precise figure.

If you are curious about your equity and not going anywhere, an automated estimate is fine. Just do not make a decision on it.

Getting one

A Home Value Review starts with the property itself: the condition, the updates, and the sales that actually compare. You get a range with the reasoning attached, and asking for one does not commit you to listing. North Alabama is here.

If you want to see how I read current conditions in each market, the monthly briefings carry the numbers and the market stats page puts them side by side.