Which security level to choose for windows?

YES...simple glass instead of [VSG]

for us RC2 was unfortunately way too expensive (over 7000 euros for the whole house). We are now using RC2n throughout the house, which was significantly cheaper, since apparently the glass panes are the most expensive.

Best regards
Sabine

I would maybe not approach this so generally here. It could be that an attic window doesn’t need RC2 or even RC2n. First always find and analyze the weak points in the house. Then secure those places particularly well and others accordingly less.

With us, RC2 on the ground floor (3 terrace double doors and three additional windows) costs an extra 1,800. That is worth it to me after all. I wanted to know for fun what RC3 would cost, but due to construction reasons it is not feasible with us...

I might not approach this so generally here, maybe. It could be that an attic window doesn’t need RC2 or even RC2n. First always find and analyze the weak points in the house. Then secure those spots especially well and others correspondingly less.

I just wanted to know for fun what RC3 would cost, but that’s not feasible for us due to construction reasons...

In terms of burglary protection, "ground floor equipment" is needed not only on the ground floor but also on the upper floor, where thanks to a garage or porch roof with a small ladder it is easily accessible. If weak points arise due to construction, this should be considered when positioning: for example, place the fixed element on the side protected from view and the terrace door that is easier to pry open on the side where the burglar is more likely to be disturbed quickly. And don’t forget: the class divisions are patient normative papers. Suitable for calculating the insurance premium, but for real risk reduction, a formally worse combination of constructions/components/measures can be better.

The window manufacturer has the data sheets showing which product belongs to which class in tabular form – the practically more valuable advice can certainly be given by the criminal investigator.

the terrace door that is easier to bypass placed where the burglar is disturbed more quickly.

The terrace door naturally goes where it makes sense. And not where maybe someone might someday try to use a crowbar. If that is the guiding principle, I recommend a sealed bunker.

Suitable for calculating the insurance premium

Maybe if you have a Picasso in the room to be protected. Otherwise completely irrelevant for the typical policy that is generated online with two clicks.

Don't be so scared...go to the right gym, there you'll meet all the serious criminals in the area. They will be your friends and you won't need to lock anything anymore. Karsten