Hello.
Nice that you want to add buildings but… can you please avoid tracing buildings on aerial imagery.
We do not do this in Belgium.  Every time someone does this, it takes ages to repair and slows down the effort to add missing buildings even more.
In this area of Belgium (Flanders), the reference for building outlines is "Digitaal Vlaanderen GRB", which shows the real outline without the distorsion.
Thanks.

https://wiki.openstreetmap.org/wiki/WikiProject_Belgium/Building_and_address_import