Example
What does it look like in practice?
Apartment No. 10 in the ad may correspond to SOS with identifier, purpose "dwelling, apartment", floor and area. Basement #10 may have been described as an annex to it rather than a second property with its own identifier.
For a garage or studio, check exactly how it is designated and described in the title deed.
What is it commonly confused with?
A door number, an internal layout or a separate electricity meter does not by itself create a separate real estate. Conversely, a SOS may include parts at different levels if so approved and reflected.
"Apartment" in an offer does not guarantee the cadastral and construction designation "dwelling".
Why does it matter?
The buyer must know whether they are acquiring a self-contained unit, undivided shares in common areas or only an agreed right of use. The difference affects the notarial transfer, mortgage financing, future sale, taxes and the ability to dispose of the property independently.
The exact identity also protects against checking a document that only applies to the building or lot.
What to ask
What should you check next?
Compare the identifier, purpose, floor, area, neighbors and appurtenant parts in the scheme, project, contract and notarial deed. If the object has not yet been mapped, ask for its design designation and clear traceability to the future cadastral code.
Ask specifically which parts will be freestanding and which will be transferred as appurtenances, common parts or usufruct.