What protection against burglary do you have? - Cost estimate?

That is a bit my problem. The retractable staircase is in the upper floor hallway, which is very small, so not in a remote, rarely used corner. And there will probably be no visually satisfactory solution. You would have to construct some kind of frame that can be locked into the masonry of the adjacent rooms by sliding it.

I will not put too much energy into it for the time being, because I have effectively sealed the roof window in the attic and no one will easily climb in through the roof tiles and rafters. They would have to bring a saw with them for that.

I think you are mistaken there. If someone really wants to get in, they push up a few pans or take them out, jump once, and have already landed through the insulation in the attic. Well, maybe you still have to clear a piece of batten out of the way.

What is also clear is that whoever takes this route probably isn't looking for the 30 euros for the next shot, but knows that there is something special in the house that they want.

Maybe, but I still don't want to build a castle because of that. Anyone who wants to come in will come in, I understand that too. Securing the hatch doesn't help me much either. The floor up there is covered with chipboard panels, but you can probably get through that somehow, since it's not a concrete ceiling.

So we will have all windows on the ground floor and one window in the basement (light well) equipped with an RC2 fitting and lockable window handles. The RC2 fitting costs €30 and the lockable window handle an additional €15. The glass itself is standard triple glazing.
Our window manufacturer has 4 security levels, which of course differ in price:
• Security level 1: security window with fitting according to RC 1
• Security level 2: security window with fitting according to RC 2
• Security level 3: security window according to RC 2 N - with certificate
• Security level 4: security window according to RC 2 - with certificate

I’m asking again here. In your case, is it about a new build, or does it also refer to a retrofit?

This retrofit is incredibly important to me because I am very afraid of a break-in, but I am almost losing faith over how much retrofitting such mushroom head locks is supposed to cost.

On the ground floor in the living room we have 3 "normal" windows in the bay, a proper balcony door, and two other window panes that can’t be opened but can certainly be pried open. Additionally, there is a double window each in the kitchen and another window on the ground floor and one more in the guest toilet. If we have mushroom head locks installed on these 11 windows, apparently about €4500 will be due. This price now includes retrofitting the locks and lockable handles and installation by a professional. Installing it ourselves we consider nonsense; we can’t do that, something would break afterwards or the locks would not fit properly and provide no protection, that would be saving money in the wrong place.

But over €4000 for windows that are at least 22 years old? And what if the installation doesn’t go well and then due to extra work time we end up over €5000? That seems extremely expensive to me.

As far as we now understand, these mushroom head locks are invisible and therefore visually better. I also read about such surface-mounted devices that can’t be visually hidden but are supposed to be comparable to such mushroom head locks in terms of resistance? Of course, I also want a visually nice solution, but almost €5000 for retrofitting such mushroom heads seems simply extremely expensive because of the large number of windows... but I do want additional security after all.

Is it a new build in your case, or does this also apply to retrofitting?

hello, in our case it is a new build. Retrofitting is expensive. I would, for example, take a look at Abus (FOS550) or other manufacturers of retrofit solutions.