Hello @malte1030.

Thanks for the notes but sometimes you make it really hard for other people, who have to guess what you thought about.

There are potentially 3 school buildings here
https://www.openstreetmap.org/way/228788112
https://www.openstreetmap.org/way/228788073
https://www.openstreetmap.org/way/228788070

The school has a website https://www.heiligefamilieschaarbeek.be:8443/

The main entrance is on housenumber 216 along Chaussée de Helmet/Helmetsesteenweg
https://www.openstreetmap.org/node/2374611026

But I don’t know how to draw the school area because it would collide with Champagnat school which we drew according to one of your other notes
https://www.openstreetmap.org/way/905956225

If you have local knowledge about how the situation really is, that would be helpful.
Thanks.