The basic element protecting the window against burglary are special anti-theft fittings.
The most common method used by thieves is to balance the entire window sash. According to police experts, burglars rarely break windows because it causes noise that can attract someone’s attention. Meanwhile, the thief’s greatest ally is peace. The ally of those who do not want to be robbed is time. There is no window that cannot be broken, but you can make it break several minutes. A thief who fails to get inside for a few minutes usually gives up.
Burglarproof fittings are the most important element protecting the window against balancing. The windows are just an addition. Fittings are rollers or mushroom-shaped pins placed on a window sash, bolting when locked in the latches attached to the frame. The fitting effectively prevents a window from being pried open, e.g. by a crowbar, where it has been installed. In professional terminology it is stated that so-called safe point. The more such points around the perimeter of the window, the harder it is to balance the sash. That is why in the window, which really hinders burglary, the fittings are located around the perimeter. The minimum version is security in every corner and under the door handle. Good fittings also protect the window from being left ajar.
Depending on the level of protection, window anti-burglary elements were classified with the WK index, indicating “resistance” against intruders of the whole window sash. WK determines the time needed to break the window structure. Three classes of solutions are the most popular on the market: WK1 – a window that cannot be forced solely using muscle strength (without the use of tools); WK2 – a window that cannot be beat for 3 minutes using simple tools (screwdriver, pliers, pliers, etc.); WK3 – a window that does not even give in to a metal crowbar for at least 5 minutes. There are also higher classes, but they are not so popular – they are solutions for specialists and special services. It is also worth knowing that anti-burglary fittings of every type should be screwed to the reinforcements in the window profile, and not to the material that makes up the profile – only correct installation ensures their effectiveness.
WK1 class protections
Simple mushroom fittings are used in the WK1 class, providing basic protection. They must be mounted at least in the lower and upper corner of the window from the handle side, in the central part of the lower sash profile and in the lower hinge. Because the windows are most often balanced from the side where the handle is mounted (they put the least resistance in this place), keyed windows are used in the WK1 class windows. The mechanism works in such a way that without a closed key the handle cannot be turned. The handle should also have an insert made of hardened steel, preventing reaming from the outside. An additional protection of the WK1 window can be a blockade immobilizing the tilted sash and anti-burglary windows. The last two elements are very important especially in the case of roof windows, which are easier to balance than vertical windows – standing on the roof it is enough to kick firmly into the window frame.
WK2 class security
The window meeting the WK2 class assumptions has seven to eleven fittings. Usually these are pin or mushroom latches. For some time, fittings with a special, rather complicated design have also been available on the market – in addition to normal manipulations, such as opening and closing, they allow the entire sash to be moved away from the door frame by a few millimeters. Such a window can be called unsealed, which is useful when you are away from home for a long time. The window, despite the hooks mounted in the frame, despite the “opening” remains resistant to burglary.
The window unsealing is also not visible from the outside.
Fittings in WK2 class must reinforce all window corners at two points and the middle points of the sash profile. The handle with a key is similar to the one used in the WK1 class, and additionally has a latch system installed that prevents tampering. This protects to some extent against burglary attempts by the method used by advanced thieves, which consists in moving the bolt locking elements, which allows you to tilt the window enough to try to turn the handle on the so-called loop. Handles with an acoustic mechanism are also available on the market, making characteristic sounds when trying to manipulate them in a different way than during normal use. To additionally secure large windows or e.g. balcony doors, they can be equipped with hook bolts, reminiscent of entrance door locks. The hooks anchor in the catches attached to the frame, effectively preventing the window from opening from the outside.
The protection class WK3 assumes that the window cannot be forced through force and crowbar for at least 5 minutes. To achieve this, you need to use the best bolts and arrange them very densely – in all corners of two or larger windows four and on each side of the profile at least two. Therefore, the WK3 class window has a minimum of 16 safe points. Simple single-roller or mushroom-type fittings are rarely used in this class. Most often they consist of several bolts operating in complex self-locking mechanisms. There are several proprietary solutions of this type on the market. To strengthen the protection of the WK3 class window, it is also worth using a counter-rotating central locking mechanism, consisting of two mushroom locking rollers. The rollers are anchored on both sides of the anti-burglary catch mounted on the frame and operate on the principle of opposing force – when trying to pry one roller, the other clamps in the catch with exactly the same force as it works on the balanced roller.