When a window is a crime scene: How to protect your panes against burglars

Autumn and winter are the favourite seasons of thieves and the most popular entry point of houses are their windows. Do you know how secure your windows are? Find out everything you need to know about the various security measures, resistance classes and other anti-burglary tips in the following blog post.


Minimalistic designed living room with burglar-proof window at night

The keyword for our last article was breakout - in the context of creative energies, when converting your attic. And now we turn full circle to the opposite: breaking in. No doubt you feel quite secure. Rightfully so...  But why? Well, as most of those reading already know, few places in the world are safer to live in than Switzerland. Even so, try not to let your guard down too much. As the saying goes ‘Caution is the mother of wisdom.’

As recently as 2020, more than 24,000 burglaries were reported nationwide. So on average, every 20 minutes, someone, somewhere in Switzerland, is burgled and burglars are like electricity - they take the path of least resistance. The prime targets for the average would-be robber are your doors and windows, the so-called 30-second windows above all. Earning their name because half a minute is all it takes a fairly average burglar to prise them open with a screwdriver and pliers. And now the evenings are getting darker, this means prime time for thieves. As dusk draws in, any windows that are not brightly lit become a beacon for the robbing rogues. But doors aren’t the easiest place to start, given the robust security standards in Switzerland. So unless the thief plans to tunnel through the wall, a window as the point of least resistance would probably get their vote. But how about safeguarding your French balconies and the rose windows on the western façade I hear you cry? Read on for more insights into how to make your windows up to scratch in terms of security.

The cornerstone: Structural mechanical safety measures

Even though windows tend to represent the weakest point from a security perspective, despite - or perhaps because of - that, you have access to a range of preventive, electronic and organisational means to thwart attempted burglaries or to prevent them from happening altogether. But steady, one by one. Before you go on a mad scramble to make your home Fort Knox from top to bottom with locks and deadbolts and give the robbers short shrift, it’s worth first reflecting on whatyou want to protect and from whom. Is the top priority to thwart the progress of petty criminals armed with crowbars and screwdrivers, or are you more concerned about preserving the glittering gems, tiaras and Picassos in your attic? We’ve all grown up on a movie diet of electronic surveillance and warning systems. To tell the truth, though, rather than deterring thieves, they tend to be more helpful with reconnaissance and insurance matters after the burglary has happened.

Our recommendation: A collective solution encompassing structural mechanical, electronic and organisational security.

Renovating your windows is the single biggest thing you can do in a structural and mechanical context to help prevent burglary. But since solutions of this kind don’t come cheap, we recommend making the effort as part of a collective drive alongside other structural measures. When you’ve made up your mind to construct or develop part of a building, that’s also the best time to reconsider and rethink your window security.


  • Never plan for new buildings without also considering the latest burglary protection and make sure your due diligence includes the input of experts. Ultimately, you’ll find this a more efficient and cheaper approach than retrofitting.

  • If you are engaged in home renovation to boost the energy efficiency of your four walls, which entails replacing windows anyway, it is more than worth your while to invest in modern burglary protection at the same time.

As we said earlier: Now, as then, most home break-ins involve levering out the windows. And it’s not rocket science either. Even the most cunning of burglars resort to the lowest common denominator of screwdrivers or crowbars to gain access. The best way to fight back is the so-called mushroom head lock

Infobox Mushroom head locking

Window resistance classes

Nothing boosts your security more effectively than utilising windows that conform to the latest security standards. But the choice overwhelms.  Where do you start? How do you find the right window for you? Those on the market are divided into security classes, to help consumers assess the degree of security they offer. Specifically, in trade, the benchmark criterion for a window is its so-called resistance class, which can be used to compare windows and doors from a security perspective.

The resistance classes range between the abbreviations RC 1 (Resistance Class 1) and RC 6, whereby 1 to 6 offer the lowest and highest levels of security respectively. Always remember, however, there is no one-size-fits-all resistance class. Depending on location, different properties have to clear differing security hurdles and the burglar protection requirements can even vary within a single house. As a rule though, only classes RC 1 to RC 3 are relevant for private households, since they already offer sufficient protection.


  • What? Windows in resistance class one offer basic protection including mushroom head locking. This is most useful when trying to prevent vandalism and attempted break-ins with physical force, e.g. kicking or jumping against them.

  • Where? RC 1 windows are only recommended on the first floor or higher. For ground floor windows or those at ceiling height, higher resistance classes should be chosen.

RC2N or RC2

  • What? From a practical standpoint, windows in RC2 and RC2N classes are RC1 windows that have been further refined. They meet the same requirements, but the former come complete with additional mushroom head locking and closing points. Accordingly, they offer better protection against the window being broken open by simple lever tools like screwdrivers, crowbars or wedges. RC2N include a further safety element, namely laminated safety glass.

  • Where? RC2 or RC2N windows should be your first choice for ground floors or other particularly exposed locations. Police sources reveal that given the noise generated and the increased injury risk when breaking windows, burglars are far likelier to reach for a crowbar. With this in mind, RC2N windows also suffice for standard households on the ground floor.


  • What? As well as incorporating all the basic security measures of RC2 windows, RC3 windows must be capable of withstanding crowbars and other tools for at least 5 minutes in the namesake "five-minute test". Studies show that five minutes tends to be the threshold at which the average burglar gives up their attempt.

  • Where? RC3 windows are your premium solution of choice in burglary blackspots, like high-risk city districts or villa neighbourhoods.

Going a step further: Surface-mounted security solutions

And if all this is still not secure enough for you, worry not - the so-called surface-mounted security solutions are sure to tick your box. These are devices that are attachable to windows to further boost security and minimise the risk of burglary. They can also be removed again as required. Examples include swing bolts, window bar locks, window grilles and hinge locks. All the same, the number one choice of surface-mounted security solution on windows remains security films.

When you consider your windowpane excessively fragile, but the thought of replacing the whole window right away makes you shudder, these films offer the perfect halfway house solution. They transform conventional window glass into safety glass that is both scratchproof and shatterproof. The safety film also hold the pane together in the event of any breakage.As for the downside of these surface-mounted security solutions - the name itself gives you a clue: this kind of intrusion protection is prominent and impossible to miss given its surface-mounted configuration and some would deem this a bit of an eyesore.

Other tips to stop break-ins: Electronic and organisational security measures

Over and above the structural burglary protection measures described, you can also employ organisational and electronic protection measures to raise your security up a few notches. In this context, organisational measures mean precautions you can take as an owner or tenant and put into practice as part of your everyday life to ensure more residential security. This would include:

  • Closing all windows that are open and tilted ajar before leaving the house.

    Caution! From an insurance perspective, tilted windows and opened windows are one and the same thing! And it doesn’t take Harry Potter to turn a tilted window into one that is open. So minimise direct lines of access into your home.

  • Firstly, this can reduce overall temptation. Secondly, however, burglars cannot be sure whether someone is present.

Deployable electronic measures include the classic alarm system and video surveillance, as well as newer electronic security measures, like access control via fingerprint or palm vein scans. Modern smart homes also offer central locking controlled by mobile phone and integrated surveillance systems.