Retrofit the mushroom head - this is important

In view of the constantly increasing number of break-ins, securing your own windows is certainly important. Mushroom fittings are an effective means of doing this. You can read in detail in this article what you should definitely pay attention to when retrofitting.

Benefits of mushroom cones

If you look at the burglary statistics and the actions of the perpetrators, you can see some important things. In around 80% of the cases, perpetrators enter the house through windows or French doors. In the vast majority of break-ins, the window is pried open. Breaking in a small part of the pane and then operating the window handle from the inside only account for around 5% of all burglars.

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A primary goal in window security must therefore be to protect the window as well as possible against being pried open. If it is possible to make this impossible for the perpetrator, or to make it very difficult, he will usually give up the break-in.

Therefore, in addition to lockable window handles and reinforcing the glazing with security foils, mushroom cams are the most important measure when securing windows.

Function of mushroom cones

Normally, a window fitting only has ordinary tenons (simple roller cams) if it is not a security window with a defined resistance class.

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If the roller pin is exchanged for a mushroom head (looks exactly like this, hence the name), this pin gets stuck in a recess on the window frame, which also has to be re-assembled. This form-fitting connection makes it very difficult or even impossible to pry open (special tools are always required to pry open).

As a rule, mushroom studs are not only installed in one place on the window frame, but in several places. The larger the window, the more mushroom fittings should be distributed around the frame. However, an exact number is not specified in the standards either.

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Install yourself

To retrofit such fittings, you only need a little skill and a little basic understanding of the mechanics of a window. If in doubt, however, you should let an expert do this work. The installation must always be carried out in accordance with the standards.

Retrofit kit costs

The cost of retrofit kits varies, and larger windows may also require several kits. Normally, the costs for a retrofit kit with the corresponding screws range between around 180 and 250 EUR.

Overall, the costs per window represent a relatively high investment. But they are also the most important protection against the preferred approach of most intruders.

Cost calculation

In case of doubt, however, in view of the high costs, you should also calculate a window replacement. Especially if your windows no longer have up-to-date U-values anyway. Together with the possible funding for a window replacement, you may even get away with it cheaper than if you retrofit mushroom cams, lockable window handles and safety film individually.


As an alternative, you can also use so-called screw-on locks. They are not particularly beautiful, but they are significantly cheaper and almost as effective.