Anti-burglary windows: RC1-RC3 resistance classes and when you really need them

Burglars don’t break through a wall: they come in through the window. Italian ISTAT statistics and studies from the national police agree: over 80% of residential burglaries in flats and houses happen through windows and doors — service doors, ground-floor windows, skylights, forced shutters. A standard “domestic” window with no anti-burglary specification opens with a screwdriver and ten seconds of pressure. The European standard that measures how well a window or door resists a break-in attempt is EN 1627, complemented by EN 1628-1630 for testing. In this article I explain what the RC1-RC6 classes are, when each one makes sense, and what it really costs to move up a class.

What EN 1627 measures

EN 1627 (adopted in Italy as UNI EN 1627) defines six resistance classes against attempted break-in. Each class corresponds to a presumed type of burglar and a minimum resistance time tested in a laboratory with specific tools.

The test is physical and severe: certified technicians genuinely attempt to force the window using the tools set out for the target class, for the specified time, applying the specified forces. If the window withstands the attempt without being breached (that is, without opening wide enough to let a person through), it passes the class.

The six classes

RC1N (resistance class 1)

• Resistance to opportunistic break-in attempts using physical force (kicks, punches, shoulder-barging)
• No tools involved
• Test duration: forces applied for a limited time
• In practice equivalent to “a well-built standard window”: multi-point hardware with 4-6 locking points, no specific tool-resistance testing.
• Suited to: flats from the third floor upwards, low-risk settings
• Added cost vs a standard window: €0-50 per window (almost always included as standard)

RC2

• Resistance to break-in attempts using screwdrivers, pliers, wedges
• Minimum resistance time: 3 minutes against an “opportunistic” burglar
• Test: application of screwdrivers of various sizes, pliers, wedges, weights
• Suited to: ground floors and first floors in urban areas, terraced or semi-detached houses, settings with passing traffic (noise discourages lengthy break-in attempts)
• Realistic added cost: €80-200 per window

RC2N

• The “N” (no glass) variant of RC2: same frame/hardware but without glass testing
• Used when the glazing is secondary (e.g. next to a grille or bars)

RC3

• Resistance to a professional burglar using a crowbar, chisel, second screwdriver, percussion tools
• Resistance time: 5 minutes
• Test: a burglar with a full kit genuinely tries to force entry for 5 minutes
• Suited to: isolated detached houses, countryside homes with no direct neighbours, exposed commercial premises
• Realistic added cost: €250-450 per window

RC4

• Expert burglar using striking tools (axes, hatchets, hammers), battery-powered saw
• Resistance time: 10 minutes
• Suited to: vaults, jewellers, banks, very high-profile residences
• Added cost: €800+ per window. Above the residential bracket.

RC5

• Power tools (angle grinder, hammer drill) for 15 minutes
• Practically limited to professional technical applications

RC6

• High-power professional power tools for 20 minutes
• Only for extreme-security applications (sensitive depots, embassies)

What makes a window anti-burglary

Moving up a resistance class isn’t a simple “label”: it requires concrete changes in four areas:

1. Reinforced multi-point hardware

Hardware is the heart of anti-burglary performance. A standard RC1 window has 4-6 locking points with simple linear cams (basic hooks). On an RC2 window this moves to mushroom-head cams (P- or T-shaped) that engage steel keeps, with the number of locking points increased (8-12 per sash). On RC3 the cams are reinforced and security plates are added behind the hinges.

Only a handful of brands make certified hardware:

• Maco Multi-Matic / Maco RAIL with ESR keeps and Tronic cams
• Roto NT Designo with V-fix locking points
• Siegenia Titan AF with anti-forced-entry system
• GU UNI-JET Anti-burglary

Certified RC2 hardware costs the window maker €80-150 more than the standard version.

2. Laminated anti-shatter glass

On an RC2+ window the glass is part of the system: it must withstand impacts without breaking and giving way. The solution is laminated glass:

• Laminated 33.1 (3 mm + PVB 0.38 mm + 3 mm): standard, RC1
• Laminated 44.2 (4 mm + 2×PVB 0.38 mm + 4 mm): standard RC2
• Laminated 44.4 (4 mm + 4×PVB 0.38 mm + 4 mm): RC2-RC3
• Laminated 66.4 or 88.4: RC3-RC4
• Laminated 66.8 + internal polycarbonate: RC4-RC5

PVB (polyvinyl butyral) is the plastic film between the panes: it holds the fragments together if the glass breaks, preventing anyone from passing through. It’s what makes the difference between a car windscreen (safe) and plain glass (which cuts like an axe blade).

Typical build-up on an RC2 anti-burglary window:

• Outer pane: 4 mm float glass (sacrificial, breaks first)
• Cavity: 16 mm with argon
• Inner pane: 44.2 laminated with low-E coating

3. Anti-lift hinges

A classic break-in technique is lifting the sash off its hinges to remove it. Anti-lift hinges (U-shaped with a pin locked from above, or concealed hinges with an anti-lift system) make this manoeuvre impossible. They’re standard on RC2 from reputable brands.

4. Key-locking and push-button handles

A standard handle opens from the outside if someone breaks the glass and turns the inner handle. Solutions:

• Key-locking handle: won’t turn without the key. Standard on RC2.
• Push-button handle: locked with the button, only opens by turning again with a specific release
• Secustik handle (Hoppe): a patented mechanism that prevents external rotation even under force

5. Reinforced frame

On RC3+ windows, additional steel reinforcements are added inside the PVC profiles and heavier-section aluminium profiles are used. PVC is a good anti-burglary material up to RC3 — to see how a serious PVC profile is built, read the complete guide to PVC windows; for RC4+ solid aluminium is the way to go.

When each class actually makes sense

RC1 — always standard

In practice, any well-made modern window today is effectively RC1 already, even without formal certification. You don’t need to ask for it specifically, it’s included.

RC2 — for lower floors and houses

This is the sweet-spot class for 90% of residential cases:

• Ground-floor and first-floor flats (and sometimes second floor) in cities
• Terraced or semi-detached houses
• Countryside houses with neighbours but still somewhat isolated
• Ground-floor professional offices and businesses

The €80-200 added cost per window is recovered by the insurance discount on burglary cover alone (many policies offer 5-15% off with documented certified RC2 windows).

RC3 — for isolated houses or specific settings

Makes sense when:

• Isolated detached houses, with no direct neighbours, in areas with long police response times (>10-15 min)
• Homes with documented valuables (collections, art, jewellery)
• Replacement in a setting where a break-in attempt has already happened
• Technical rooms housing valuable equipment (servers, professional gear)

The added cost for RC3 is €250-450 per window: for a flat with 6-8 windows that’s an extra €2,000-3,500 overall. Worth evaluating case by case.

RC4+ — professional applications

Not residential in the normal sense. This bracket is for banks, jewellers, some hotels, VIP residences with security details. Costs of €800+ per window.

Practical mixed strategies

You don’t always need to fit the whole flat to the same class. A rational strategy is:

First-floor flat in the city:

• Windows facing the main street or a shared walkway: RC2 (these are the weak points)
• Windows facing a protected inner courtyard or on upper floors: standard RC1

Isolated detached house:

• Front door: its own class (security doors class 4-5)
• Ground-floor windows + garden French doors: RC2 or RC3
• Upper-floor windows: RC1-RC2

Countryside house:

• Entire ground floor: RC2 minimum
• Roof-accessible skylights: RC2 (these are often forgotten)

You save money by keeping maximum security exactly where it’s genuinely needed.

What to ask for in an anti-burglary quote

These need to be in writing:

1. Declared RC class of the window (RC1N / RC2 / RC3) with the manufacturer’s certificate
2. Hardware brand and model (e.g. “Maco RAIL RC2”) with anti-burglary code
3. Glass build-up: laminated 44.2 / 44.4 with technical code
4. Hinge type: specifically stated as “anti-lift”
5. Handle: key-locking / Secustik / push-button
6. Certification: test report from IFT Rosenheim or another accredited laboratory

If the quote just says “anti-burglary hardware” without specifying the class and brand, it’s a generic promise with no technical value.

Realistic added cost summary

Average estimate for a residential 120x140 cm PVC window:

• From standard to RC1N: included
• From RC1N to RC2: +€80-200
• From RC2 to RC3: +€200-300 (cumulative +€280-500)
• From RC3 to RC4: +€400-700 (cumulative €700-1,200)

For an average flat with 8 windows + 1 French door, moving everything up to RC2 from standard costs roughly €1,000-2,500 in added cost — to see how that fits into the total cost of a project, read how much it costs to replace the windows in your home. It’s often the item with the best security-to-price ratio in the whole job.

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To work out whether your project needs RC2 or RC3, request a quote: we assess exposure, the urban setting, accessibility, and put together a differentiated proposal window by window. No “everything at RC3” if targeted RC2 is enough — and no RC1 where you genuinely need RC2.