Burglar-Resistant Windows: RC1, RC2 and RC3 Explained

Most burglars do not come in through the front door but through windows and patio doors – usually by levering the sash open with a simple tool. The good news: the right features make this much harder. We explain the resistance classes RC1 to RC3 and show which security features really count with new windows.

What do RC1, RC2 and RC3 mean?

The standard EN 1627 divides windows and doors into resistance classes (RC). It tests how long an element withstands a break-in attempt with certain tools. Three classes are particularly relevant for residential buildings:

• RC1 N: basic protection against physical force such as kicking or shoulder charges, hardly any protection against levering tools.
• RC2 N / RC2: protection against opportunist burglars with simple tools such as a screwdriver, pliers and wedges – resistance time three minutes. RC2 N does not require safety glass; RC2 additionally uses attack-resistant glazing (P4A).
• RC3: protection also against a crowbar and a second screwdriver – resistance time five minutes.

Security experts recommend at least RC2 for easily accessible windows and French doors. As most burglars give up if they cannot get in quickly, every minute of resistance makes a difference.

These features make windows secure

• Mushroom-head cams and security keepers: they hook the sash and frame together all the way round and prevent levering. Our standard Roto NX hardware can be equipped up to RC2.
• Lockable handle: it prevents the handle from being turned from outside through a hole in the glass.
• Drilling protection on the gearbox: it makes it harder to drill into the hardware.
• P4A safety glass: laminated glass with an interlayer that does not allow anyone to reach through even after several blows.
• Solid installation: the best window is of little use if it is only foamed in. For burglar-resistant elements, firm screw fixing and packing at the locking points are essential.

Don’t forget patio and sliding doors

Patio doors are particularly at risk because they are often on the garden side, out of sight from the street. At Aristofenster, we fit patio and sliding doors in every system with four security locking points against levering. Roller shutters and external blinds with lift-up protection also increase security.

Which windows need which class?

• Ground floor, basement, patio doors: RC2 recommended.
• Windows reachable from canopies, balconies or garages: also RC2.
• Upper floors that are hard to reach: basic security with mushroom-head cams and a lockable handle.

Tip: local police crime prevention advisers often offer free advice on burglary protection. When planning new windows, ask specifically about the resistance class – it should be stated explicitly in the quote.

You will find suitable systems among our PVC windows and entrance doors. Read more about front doors in our front door buying guide.