Safety windows

Conversation with the FG security specialist Uwe Glock.

C. Tesch: When is a window secure?

Uwe Glock: Windows are classified according to safety classes. On the one hand, we have the standard window, which is outfitted with a specific "basic level of security". This means that it is comprised of insulated glass and features the necessary locking mechanisms in order to keep the window securely closed. In addition, there are specific classifications ranging from resistance class (RC) one to five. With respect to wood and aluminium, we primarily deal with a resistance class one or two, which are also sufficient for standard building codes. With the security classes, the fittings, the type of glass and way the window is built into the masonry are all upgraded.

C. Tesch: How do the security classes differ, for example if we take a look at the fittings?

Uwe Glock: The fittings are outfitted with so-called mushroom cams. This means that the locking cams mesh together in a U-shaped manner in the window's casement and frame elements. In other words, they're covered on three sides. This prevents the window from being moved laterally and therefore from being removed. The higher the resistance class, the more locking points, that is the more cams.

C. Tesch: What are the various types of glass available?

Uwe Glock: In terms of types of glass, there is the 2x4 mm standard glass, which can be upgraded. Also in this case, there are various security classes. Security glass is equipped with a composite glass of varying thickness. There is a plastic layer between the double pane. As a result, the glass is not only thicker, but also sturdier. The plastic layer between the panes ensures that the second pane of glass remains intact even if the first one is shattered. The plastic layer is not visible to the naked eye. Thicker types of glass may, however, decrease the colour intensity. A "grey, drape effect" may result. However, this effect is generally found with thicker types of glass.

C. Tesch: Is it still possible to shatter windows that have security glass?

Uwe Glock: Theoretically, it is possible to shatter the pane. It is only a question of time and the tools used. There's a difference when a pane of glass is struck by a football, a brick or a hammer. But even with a sledgehammer, you'll first encounter a certain level of resistance. The resistance class is determined on the basis of how much time a burglar needs, using a certain object, to shatter the pane.

C. Tesch: How is it possible to make windows more secure, if we look, for example, at how they're installed?

Uwe Glock: The window shouldn't just be bolted into the masonry, but padding should also be used. In the process, triangular blocks of wood are inserted into the installation gap between the window and the masonry. This prevents the window frame from slipping. These three aspects, which can be varied according to the desired security level, make up a unit. It doesn't help much when the glass is reinforced, but is only bolted to the wall. In addition, it is also possible to have the windows under police surveillance. For this, safety glass is also outfitted with shatter-alarms. As a result, if the glass is shattered or tampered with an alarm is triggered.

C. Tesch: Can the burglar see these elements?

Uwe Glock: Yes, they are visible. One should imagine a small spider web, which is visible in the corner of the window. The specialised glass, which is used for these kinds of panes, immediately shatters into thousands of tiny fragments when tampered with. This results in the interruption of the closed current within the glass web, which then triggers the alarm. Electronic surveillance can also be intensified when specialised fittings are used. This means that we integrate a mechanism into the fitting that transmits a signal to the alarm system in the event of a break in.

C. Tesch: In the end, is that just as secure as having a grate in front of the windows?

Uwe Glock: Yes, absolutely. In order to pry off the bars, one would also need a certain type of tool. And of course, it is no longer necessary to have an unattractive grate in front of the windows.

C. Tesch: If I have good rolling shutters, haven't I also done a great deal for my personal safety?

Uwe Glock: There is a widespread belief that rolling shutters protect against break-ins. However, it is just a myth! They can be pried open relatively easily.

C. Tesch: FritzGlock is often involved in projects featuring sophisticated architecture, are such projects also associated with special demands in terms of security?

Uwe Glock: You see that in larger urban centres, particularly in Berlin. Sometimes, the security demands are more important than the architecture itself. This is entirely different than in regions that are not as plagued by widespread crime. Overall, security typically plays a key role in high-profile projects. For some projects, the security class is often stipulated by the insurance company.

C. Tesch: Could you estimate how much additional security costs?

Uwe Glock: This can be estimated with a high degree of accuracy with regard to the upgraded fittings. Resistance class 1 costs around approximately 30 Euros per square meter, resistance class 2 can cost up to 35 euros more per square meter. This is somewhat more difficult with glass. In general, one can expect, depending on the classification, extra costs ranging from 40 to 100 Euros per square meter of window.

C. Tesch: What does the future have in store for FritzGlock in terms of window security?

Uwe Glock: We are currently having our resistance class 2 wood-aluminium windows tested. We are going to offer it as our Twindows resistance class 2-security window.

Though we are already in the process of building these windows, certification is sometimes demanded.

C. Tesch: Thank you very much for your time.