Double Glazed Window Security Rating: What the Classifications Mean

Understanding double glazed window security ratings helps homeowners specify windows with independently verified security performance rather than relying on unverified marketing claims. Security ratings for windows are established by European and Australian standards that define test methods, attack scenarios, and performance thresholds, and products that carry these ratings have been independently tested to demonstrate their resistance to forced entry. This guide covers the main classification systems and what they mean in practical terms for Melbourne homeowners.

The EN 1627 Resistance Class System

The most widely referenced system for double glazed window security ratings is the European standard EN 1627, which classifies windows and doors into resistance classes from RC1 through to RC6.

RC1

RC1 provides resistance against physical violence including kicking, shouldering, and body impact. It does not provide resistance against tool-based attacks. RC1 is the minimum classification and does not meet the threshold recommended for residential security.

RC2

RC2 requires the window to resist sustained attack using a screwdriver, pry bar, and wedge for a minimum of three minutes at the most vulnerable points of the assembly. This is the class recommended for most residential properties and corresponds to protection against the opportunistic tool-based attacks used in most residential break-ins. Aluplast uPVC windows fitted with Safetec burglary protection hardware meet RC2 requirements.

RC3

RC3 requires resistance against more powerful tools including crowbars for a minimum of five minutes. This class is appropriate for properties with elevated security requirements.

RC4 to RC6

These higher classifications require resistance against power tools and specialist equipment for extended periods and are typically specified for commercial, government, and high-security applications rather than standard residential properties.

What RC2 Requires From the Window System

A double glazed window security rating of RC2 requires every component of the window to meet the standard.

The glazing must resist the attack scenario, which typically requires laminated glass that holds together after impact. The frame must resist deformation under the forces applied, which requires steel-reinforced profiles. The locking hardware must resist levering at multiple points, which requires multi-point locking systems with hardware specifically engineered for security resistance. The glass beading must be internal to prevent glass extraction from outside.

WERS and Energy Ratings

The Window Energy Rating Scheme provides performance ratings for double glazed windows that are separate from security ratings. WERS rates thermal transmittance, solar heat gain coefficient, and air infiltration. These ratings are relevant for NatHERS compliance and energy performance but are separate from the EN 1627 security classification system. Astellite products carry both WERS energy ratings and can be specified with RC2 security hardware.

What Astellite Offers

Astellite manufactures double glazed windows with RC2 security ratings using German-engineered Aluplast uPVC profiles, Safetec burglary protection hardware, multi-point locking systems, internal glass beading, and laminated glass options. The full range includes tilt and turn windows, awning windows, sliding windows, fixed windows, and custom windows.

Every installation is backed by a 10-year warranty. Astellite holds accreditation from AGWA and WERS and all products meet Australian building and safety standards. The team services homes in Melbourne, Geelong, Melton, and the Mornington Peninsula.