I recently valued a multimillion-dollar home in Tampa that had been purchased directly from the builder less than a year earlier.

My valuation came in roughly $600,000 below what the owners had paid.

Did the house really lose $600,000 that quickly? Maybe. But that's not necessarily what my valuation tells us.

I perform Broker Price Opinions, or BPOs, which are valuations prepared by real estate brokers using comparable sales and current market data. Banks and other financial institutions often order them when they need an opinion of a property's current value. The assignments come with specific requirements for selecting comparable properties, making adjustments, and supporting the final number.

I followed those requirements. The market evidence didn't support the previous purchase price.

That's where this gets interesting.

The Bank Turns Art Into Science

Ask a buyer, a real estate broker, and a bank what a house is worth, and you may really be asking three different questions.

A buyer is deciding what the house is worth to them. If they've been searching for a particular location, layout, or feature and finally find it, they may be willing to pay more for it.

When I'm positioning a property for sale, I'm looking at comparable sales, but I'm also looking at today's competition. How many alternatives are available? How does this house compare? What's the buyer pool at this price? Does the property have something those buyers can't easily find somewhere else?

A bank needs something different: a number it can support.

It takes some of the art inherent in real estate and turns it into a science, with parameters for comparable sales, adjustments, market data, and documentation. It isn't trying to predict what the one buyer who absolutely loves the house might pay. It needs a value that can be supported by the evidence.

And if there's a loan involved, that number can determine whether the financing works.

But They Just Paid That Much

The previous sale of this Tampa property certainly mattered. But it couldn't simply become my answer.

The owners bought directly from the builder. That transaction reflected the property, competition, and buyer decisions at that particular moment. Less than a year later, I was answering a different question using the market evidence available to me then.

I don't know why the buyers paid what they paid. I wasn't involved in that transaction, and I'm not going to manufacture an explanation after the fact.

I only know what I could support.

So Why Did the Value Fall?

On this one, quality control came back and asked how the value could have fallen $600,000. I explained my adjustments, showed the comparable sales, and supported the number.

What I can't necessarily explain is why another buyer paid a different amount months earlier.

Maybe the market changed. Maybe the competition changed. Maybe that buyer valued something about the house more than the next buyer will. Unless I have evidence, anything beyond that is speculation.

I was told the customer might call if he had questions about the number. He never did. I don't know if the loan closed, what he decided, or whether anyone ever explained the gap to him. I usually don't. My job ends with a number I can defend — not the story after it.

So my BPO didn't prove this house lost $600,000. It showed that the value I could support under the requirements of that assignment was roughly $600,000 below the previous purchase price.

That's an important distinction, and not just at the multimillion-dollar level.

The same issue comes up when someone looks at an online estimate, sees what the neighbor's house sold for, or remembers what they paid three years ago and assumes that's the answer.

It might be useful information. It isn't necessarily the answer.

A seller wants to know what a property can command against today's competition. A buyer wants to know what it's worth to them. A real estate broker has to understand the active inventory, the likely buyer pool, and where the property can be positioned. A financial institution needs a value that meets its requirements and can be supported by market evidence.

They're all looking at the same house.

They're not necessarily asking the same question.

And sometimes the difference is $600,000.

So here's my question: when you think about what your house is worth, where did that number come from — an appraisal, a Zillow estimate, what you paid, or a gut feeling?