Hello,

Here is a more detailed explanation about the issue.  (Sorry for not taking the time to explain in detail yesterday, I only had limited mapping time and rushed to restore the building because the changeset was creating issues.)

There are existing landuse areas in OSM.  Most of Belgium is already covered with them.

Areas where most buildings are public administration, are typically marked as landuse=commercial.  Here is the existing area:
https://www.openstreetmap.org/way/30087343
This is the reason why using the same tags within an existing area is not appropriate.  Don’t worry, OSM may be complicated at times and we all make mistakes.