This is considered maintenance work as long as the hole is not enlarged or the structure is not tampered with, or the appearance does not change significantly in any other way. Maintenance work does not have to be reported to the building authority. I recommend notifying the municipality, as it is quite likely that some scaffolding or other building material, container, etc. you will have on the land of the municipality, so that you do not get fined for illegal seizure of land. If you do not change the entire block of flats, and you have a cooperative apartment, you also need the consent of the cooperative.