Research & method

The method in brief

• Compared: the living area stated in the advertisement and the area recorded in the register for the same property.
• A difference of more than 5% between the two figures counts as a deviation.
• Both values are statements — neither is taken as the truth.

What the study does not claim

• No valuation: the study says nothing about a property's value or price.
• No accusations against individual properties or advertisers: it describes differences across the sample, not who is right in any single case.

Stated, not truth

That is why alpflo states register data rather than asserting it as truth, and labels every figure with one of four states:

In depth: register value is not truth

Where each figure comes from

Every figure in an alpflo report names its register and its as-of date. The registers and how current they are:

• Address, parcel (EGRID) and parcel boundary: swisstopo / GeoAdmin, official cadastral survey — fetched when the report is produced.
• Building and dwelling data (EGID, year built, heating): GWR Level A (© BFS), kept up to date by the communes — fetched when the report is produced and stated as the register's entry, not as a verified condition.
• Public-law restrictions on landownership: the cantonal PLR cadastre (ÖREB) — the extract is fetched when the report is produced and carries the date the canton publishes.
• Public-transport service quality (ÖV-Güteklasse): ARE — modelled, as of the published dataset.
• Rooftop solar potential: Sonnendach (© SFOE) — modelled, as of the published dataset.
• GEAK energy label: the cantonal GEAK register, only where a canton publishes it per building.

The register facts in one document: the property register brief

For planning professionals: the per-project plan check