This is the 1119th most frequent German word.
ursprünglich
Originally; initial; primal.
Here, 'ursprünglich' is used to describe the original state or origin of the subject, indicating their origin or starting point.
Ursprünglich komme ich aus Deutschland.
Originally, I come from Germany.
In this sentence, 'ursprünglich' modifies 'geplante', referring to the original intention or plan for the event.
Die ursprünglich geplante Veranstaltung wurde verschoben.
The originally planned event was postponed.
This usage of 'ursprünglich' refers to the original purpose or function of something, in this case, the building.