On the screen you can enlarge the cadastral map as much as you like. The fence therefore appears almost like an exactly surveyed line. However, the depiction does not yet answer what legal and surveying quality lies behind the boundary. Before a purchase or any construction planning it is therefore worth asking about the cadastre status and the relevant documents.
Screen resolution is not surveying quality
The Federal Office of Metrology and Surveying explains that boundary cadastre and land tax cadastre are displayed together in the digital cadastral dossier, but have significant quality differences. It warns against inferring quality from scale-free enlargement. For boundary lines that exist only graphically in the land tax cadastre, measurements taken from the map are not reliable. [BEV]
Our editorial recommendation: Note the parcel number and cadastral municipality and ask about the actual status. Label your own printout with the retrieval date and purpose of use. Do not turn a line drawn on screen into a distance specification that is passed on as established.
Separate existing surveys from the visible condition
Collect plans and other existing surveying documents. Describe alongside what you can see in the field: a fence, a hedge or an old boundary stone. This observation is initially only an observation. Which agreement there is with the authoritative boundary course must be clarified on the basis of suitable documents and by authorised specialists.
The BEV describes a binding boundary determination for the boundary cadastre and points out different bases of depiction for land tax cadastre parcels. [BEV] The article does not draw its own assessment of a disputed boundary from this.
Example: The garden shed appears to stand barely within the boundary
In the hypothetical purchase interest a new garden shed is to be built in a marginal area. An enlarged map excerpt seems to show enough space. Instead of reading off a distance yourself, the interested party presents the parcel details, existing plan and their rough project sketch to a suitable specialist. The question is: which boundary basis must be clarified for a reliable plan?
Only after this clarification will the distances and other requirements relevant to the project be dealt with professionally. The digital printout remains an orientation aid and must not inadvertently become a surveying deed.
What information you should obtain
The result should state which documents support the course, what is still unclear and which next step is required. Costs, procedures and possible conflicts are discussed separately for the specific case. Do not move any boundary markers on your own authority. This process deals with neither disputes over ownership nor building permission, but with the correct basis for the next technical question.