Security windows

Security windows protect the glazed openings of a building against forced entry. The frame, glass and hardware are tested as one unit to LPS 1175, so the window resists attack as a complete assembly. ArxBridge supplies and installs rated window systems across the UK for commercial and residential projects.

• LPS 1175 testedFrame, glass and hardware as one unit
• SR2 to SR4B3, C5 and D10 ratings
• Steel and aluminiumFrames to suit the building
• UK wideSurvey, supply and installation

About security windows

A security window is a complete window system whose resistance to forced entry has been proven by test. The rating applies to the whole assembly: the frame profile, the glazing, the beads, the hinges and the locks. A strong pane of glass in a weak frame is not a security window, and the test makes sure no such weak point exists.

The frames are steel or aluminium, formed into profiles that carry multi point locking and laminated security glass. Opening lights use hinges and locks that resist jemmying and cutting, and fixed lights are beaded in a way that stops the glass being removed from outside. Every part of the window works against the same attack.

Security windows look like normal windows. The rating is in the construction, not the appearance, so architects can protect a facade without changing its design. Fixed lights, top hung openers, tilt and turn units and sliding systems can all be built to a rated specification.

Which rating do you need for security windows

Match the window rating to the rating of the doors on the same elevation. A high rated door next to an unrated window leaves an obvious route in.

The full scale runs from A1 (SR1) to H20 (SR8), as set out in the LPS 1175 ratings guide. European projects sometimes ask for the EN 1627 RC classes instead; RC1 to RC6 cover burglar resistance in a different test format, and the two scales should not be mixed on one schedule.

Specifier note. Always specify the window as a tested unit, not as separate glass and frame. A security laminate in an ordinary frame has no rating, because the rating belongs to the tested assembly.

Construction of security windows

The frame starts as a steel or aluminium profile designed for the rating. Deeper profiles carry heavier laminated glass and more locking points, which is why higher rated windows have a visibly chunkier section. The corners are welded or mechanically jointed to resist being forced apart.

The glazing is laminated security glass, bonded to the frame so it cannot be pushed out. The interlayers hold the pane together under attack, and the bond to the frame stops the whole unit being levered out. LPS 1270 rated glazing can form part of the build up where the specification calls for tested glass as well as a tested frame.

Hardware completes the unit. Multi point locks engage the opener into the frame at several positions, hinges are protected against lifting, and handles are lockable. The finished window is supplied with third party test evidence for the exact configuration ordered.

Pairing security windows with other ratings

Where the threat includes firearms, the window system can carry glazing rated to the BR classes of EN 1063, as used in bullet resistant windows. Where blast is a concern, the frame and glass are engineered as a blast resistant window system with its own hazard rating.

On the same facade, the windows should match the doors. A C5 window beside a C5 doorset gives a consistent line; mixing ratings leaves the lower rated element as the route an attacker will choose. Fire rated doors on the escape routes carry their own E or EI classification, which is a separate test from forced entry. The Security range covers the doors, windows, grilles and shutters for the whole facade, so every opening can carry a matching rating.

Where to use security windows

Residential and housing projects use rated windows at ground floor and accessible levels, where PAS 24 or LPS 1175 B3 covers the realistic threat. Education buildings use them at ground floor classrooms and entrances, where vandalism and break in attempts are the daily concern.

High-value retail units need windows that resist attack out of hours, particularly where the shopfront is fully glazed. Healthcare, utilities and commercial buildings use rated windows for plant rooms, records stores and any room whose contents justify the upgrade.

What sets the cost and lead time for security windows

The rating is the main driver: each step up the LPS 1175 scale adds steel, glass weight and locking points. Size matters too, because large panes need heavier laminated build ups and deeper frames. Opening lights cost more than fixed lights at the same rating, since the hardware must be tested as part of the unit.

Finish, colour and any acoustic or thermal upgrades add to manufacture time. Site access for large or heavy units, and the need for out of hours working in occupied buildings, affect the installation programme. A site survey and a clear schedule of window types are the only reliable basis for a quotation.

How to specify security windows

1. Set the rating per elevation. Match the windows to the doors on the same facade.
2. List every window type. Fixed, opener, tilt and turn and sliding units each need their own tested configuration.
3. State the glass performance. Confirm whether thermal, acoustic or solar control is needed alongside the security rating.
4. Agree the finish. Colour, internal and external faces, and any heritage constraints.
5. Confirm the test evidence. Ask for third party test evidence covering the exact unit ordered.
6. Request a detailed quotation. Send the window schedule and drawings for a fixed proposal.

Frequently asked questions