Security classes of locks RC1–RC6: how to choose the right one

Have you come across the labels RC2 or RC3 on security doors and wondered what they actually mean? Security classes according to standard ČSN EN 1627 describe how well a door system resists attempted burglary. In this article, we explain what each class means and which one to choose for an apartment, house, or business premises.

The RC marking is frequently seen on new security doors, as well as on hardware or complete door systems sold as certified sets. If you are choosing doors for the first time or addressing security after a break-in or moving into a new flat, it is useful to understand what each class represents, and not to be misled by marketing terms such as "security" without a clear number following them.

What do security classes RC1 to RC6 (CSN EN 1627) mean?

Standard ČSN EN 1627 classifies the resistance of doors, windows and other building elements against burglary into six classes, designated RC1 to RC6. The higher the number, the more sophisticated tools an intruder needs to overcome the barrier, and the lower the probability that they will gain entry before giving up or being interrupted.

Which class is suitable for an apartment and which for a house?

For an apartment in a block of flats where entry is monitored by the main door and possibly a caretaker, class 3 is usually sufficient. RC2. For detached houses, ground-floor flats or flats in areas with a higher risk of burglary, we recommend the following as a sensible minimum. RC3. Offices, warehouses and premises with valuable assets should consider RC4 and higher.

If you are unsure of the class of your current doors or lock cylinder, check the label or manufacturer's certificate: a certified product should have the class stated directly in the documentation or on the packaging. If you do not have the documentation, we will advise you by phone or on-site based on the type of door, hardware and lock cylinder.

Cylindrical inserts versus security fittings: what each one handles

The insert and hardware protect the door against various types of attack, and certification according to the RC class always applies to the entire door system, not just one of its components.

• Cylindrical insert protects against entry via the lock: drilling, planchetting or so-called bumping.
• Security fittings Protects against prying and impact on the door itself and prevents the lock cylinder from being pulled out from the outside.

If you require a genuinely high security class, replacing just the lock cylinder is insufficient; the entire door must be addressed. We discuss selecting a lock cylinder in more detail in our article. How to choose a cylindrical insert.

Insurance companies and safety class

A number of insurance companies take the level of security on entrance doors into account when arranging home or property insurance, for higher insured amounts, a specific security class or lock type may be a condition for full coverage in the event of a burglary. Before you arrange or adjust your insurance, we recommend verifying the conditions regarding security directly with your insurer.

It pays off even outside insurance: a higher security class of doors extends the time an intruder would need to gain entry, and for many flats and houses this alone deters attempted break-ins. Investing in a better core or fittings also usually translates into a higher property value in the event of a sale or letting.

We will be happy to arrange the replacement of the core or the installation of security hardware to a higher class for you, please visit our website. Replacement of the cylindrical liner or for a complete Price list for locksmith services.

Also read: How to choose a cylindrical insert: types and safety features →