How BuyerWingman Cross-Checks Property Documents to Find What Doesn't Add Up

By the time a buyer is close to offering, they usually hold a listing, a registry extract, a cadastral record, some floor plans, a set of photographs, a handful of emails from the agent and a few remembered sentences from the seller. Perhaps an architect's note. Perhaps a survey.

Each of those documents, read alone, tends to look reasonable. They are formally produced, internally consistent and mostly accurate about the thing they describe. The problem appears only when you put them side by side.

The problem, in one example

No single document here is obviously wrong. Taken together, they describe a property whose physical extent and recorded extent have diverged by roughly 52 m² — and that divergence has consequences for lending, tax, resale and extension rights.

A buyer reading these documents one at a time, across several weeks, in between viewings and work, will often not notice. Read simultaneously, the question is unmissable: where is the licence for the difference?

The BuyerWingman method, step by step

1. Gather

Everything goes into one place: the listing, the registry and cadastral information, plans, licences, certificates, survey and architect reports, photographs, and what the seller or agent has said. Statements count as evidence — they are simply weaker evidence, and are labelled as such.

2. Classify the source

Each document is identified for what it is: an official record, a professional report, a marketing document or an informal statement. Classification determines how much weight a fact carries later, so it happens before anything is extracted.

3. Extract the facts

Structured values are pulled out of each document — areas, plot size, room counts, year of construction, cadastral reference, registered owner, charges, licence dates, energy rating, observed defects. Each fact keeps a pointer back to the exact document it came from.

4. Record the status of every fact

This is the step that makes everything afterwards trustworthy. A fact is never stored as simply true. It is stored with the strength of its source attached.

• Verified Fact — supported directly by documentation or another confirmed source.
• Seller / Agent Claim — provided by the seller, agent or listing, but not independently verified.
• AI Inference — a reasoned interpretation drawn from the available evidence, clearly labelled as interpretation.
• Public Data — obtained from external or public sources.
• Unknown — something that still needs to be established.

The distinction matters because buyers make decisions on mixed-quality information without realising it. "The pool is legal" and "the agent said the pool is legal" feel similar in conversation and are entirely different in a negotiation.

5. Compare facts across sources

The same attribute is lined up across every document that mentions it. Built area from four sources. Plot area from three. Bedroom count from the listing, the plan and the photographs. Year of construction from the registry and the cadastre.

6. Detect conflicts

Where values disagree beyond a sensible tolerance, a deviation is raised — with both values, both sources and an explanation of why the difference might exist. Some deviations are methodological and resolve immediately. Others point to unrecorded work.

7. Identify what is missing

Absence is harder to notice than contradiction, and often more important. If photographs show a pool, there should be a pool licence. If a lower-ground room is furnished as a bedroom, there should be documentation covering the conversion. Missing items are listed as findings in their own right, each with a suggested request you can send to the seller or agent.

8. Assess the risks

Findings are grouped into risks with a severity and a plain explanation: what the issue is, what it could cost, how likely it is to matter, and what would resolve it. Severity reflects consequence, not alarm.

9. Explain the consequences

Each risk carries through to the parts of the analysis it affects — the valuation, the renovation range, the deal economics. A missing licence is not just a legal note; it is a line in the risk-adjusted value, traceable back to the document that raised it.

10. Recommend what to verify professionally

The output is a list of specific questions for specific people: this one for your lawyer, this one for an architect, this one for a surveyor, this one for the seller in writing. Precise questions get precise answers, and they cost less professional time than open-ended ones.

Why evidence status changes how you buy

Consider two properties. In the first, the built area is confirmed by the registry, the cadastre and an architect, and the pool licence is on file. In the second, the built area is supported only by the listing and the seller's recollection, and no licence has been produced.

Both properties might be perfectly good. But they are not the same purchase, and they should not command the same price. Evidence strength is a property characteristic, in the same way that orientation or plot size is.

That is why BuyerWingman reports evidence strength alongside its findings. It tells you how much of what you believe about a property is actually confirmed — and points at exactly what is not.

What BuyerWingman is not

It does not replace a lawyer, an architect, a surveyor, an engineer, a tax adviser or a certified valuer. It does not certify legality, it does not issue valuations for lending, and it does not pretend that an inference is a fact.

What it does is make the whole picture visible in one place, so that the professionals you pay are answering the questions that actually matter, and so that you can see the reasoning behind every conclusion. The important question is never simply what BuyerWingman thinks. It is why BuyerWingman thinks it.

If you want the practical groundwork behind this method, start with the documents you should request and why listing square metres may be wrong.

Know the property. Know the risks. Know your numbers.

That sequence is deliberate. You cannot assess risk on a property you do not accurately understand, and you cannot arrive at a defensible number until the risks are named and quantified.

Do those three things in order and the decision becomes much simpler — not because the property is perfect, but because you finally know what you are buying.