Is it an official appraisal?

No. It is a commercial valuation report. A mortgage or court case requires an approved appraisal company.

What happens if the owner's price is out of market?

The dossier shows it with the divergence from the calculated band and the numerical argument for the conversation.

Does it work in Portugal?

Yes, with INE Portugal and caderneta predial.

Spanish, Portuguese, Catalan, Galician, Basque, English, and French.

Google Cloud, europe-west1 region (Belgium). See Trust.

How the Nexus valuation engine works

A number that cannot be audited is worthless to an owner. That is why every Nexus value can be traced line by line back to its source.

1. Official sources first

Catastro (Sede Electrónica). By catastral reference or PDF. Reads built area, use, floor, year, and linked annexes (garage, storage, terrace). When the PDF abbreviates or splits numbers, the system recomposes them and checks that the sum matches the declared total; if it doesn't match, it reverts.
INE. Housing prices, rents, and demographics by municipality; in Madrid and Barcelona also by neighborhood (Ayuntamiento/Registradores; Generalitat/Registradors).
Registradores and municipal appraised value (MIVAU). Anchor the value when portal supply deviates from the real market.
SERPAVI. Rent reference for lease and investment dossiers.

2. Comparables

Active portal listings in the same area and typology. Filtered for consistency (area, condition, price per sqm) and those that don't fit are discarded. The dossier shows the comparables used and the ones set aside, with a note.

3. Deterministic arithmetic

Median of filtered comparables.
Adjustment for condition (needs renovation / good / renovated) within a declared band.
Annexes valued by component (for example, a parking space is not double-counted: it either enters as an annex or enters the comparable, never both).
Value band and central value. Rounded to hundreds.

The same input produces the same result. There is no random sampling in the value calculation.

4. AI drafts, it doesn't value

The language model writes the market analysis, strengths and weaknesses, and dossier text. It never writes the final value: numbers are inserted afterwards, from the engine, into fixed tags. If the text contradicts the engine, the engine rules and a consistency audit flags it with the percentage divergence.

5. Auditable receipt

Every number in the dossier includes: the applied formula, input data, source, and query date. An agent can reproduce the calculation by hand.

6. Fail-closed

If the Catastro does not respond, if there are not enough comparables, or if a data point is inconsistent, the system returns a clear error and the credit. It never fills in with a plausible number.

7. Human always in the loop

The agent reviews, adjusts, and signs. Nexus amplifies the professional; it does not replace them.

Frequently asked questions

Is it an official appraisal?: No. It is a commercial valuation report. A mortgage or court case requires an approved appraisal company.
What happens if the owner's price is out of market?: The dossier shows it with the divergence from the calculated band and the numerical argument for the conversation.
Does it work in Portugal?: Yes, with INE Portugal and caderneta predial.
In what languages?: Spanish, Portuguese, Catalan, Galician, Basque, English, and French.
Where is my data?: Google Cloud, europe-west1 region (Belgium). See Trust.