So , You've Bought Secondary Glazing Safety Features ... Now What?

· 6 min read
So , You've Bought Secondary Glazing Safety Features ... Now What?

Secure and Sound: An In-Depth Guide to Secondary Glazing Safety Features

Secondary glazing is frequently lauded for its remarkable thermal insulation and acoustic performance. However, beyond its ability to dampen the holler of city traffic or slash heating expenses, it serves as a crucial security and safety layer for property and business homes. For heritage structures and conservation areas where changing original windows is forbidden, secondary glazing uses a non-obtrusive method to bring high-level security to standard structures.

This short article checks out the various safety functions related to secondary glazing, ranging from high-performance glass types to advanced locking mechanisms and fire escape considerations.


The Role of Glass in Safety and Security

The glass used in secondary glazing is substantially various from the thin, delicate panes found in historic single-glazed windows. When secondary glazing is installed, the option of glass is the main factor of how the unit will behave under effect.

Toughened Safety Glass

Toughened glass, likewise referred to as tempered glass, is heat-treated to increase its strength compared to typical "float" glass. If it does break, it shatters into thousands of small, granular portions instead of sharp, jagged shards, considerably decreasing the risk of injury. This makes it a perfect option for low-level windows or high-traffic locations where unintentional effect is a risk.

Laminated Security Glass

Laminated glass is the gold standard for security. It includes two layers of glass with a polyvinyl butyral (PVB) interlayer sandwiched between them. Even if the glass is struck with substantial force, the interlayer holds the pieces together, maintaining a barrier that is extremely tough to permeate. It is frequently utilized in jewelry stores and banks, making it a powerful deterrent versus intruders in a property setting.

Table 1: Comparison of Glass Types for Secondary Glazing

Glass TypeSecurity LevelSecurity CharacteristicFinest Use Case
Standard FloatLowBurglarize dangerous fragmentsNot recommended for safety
StrengthenedMediumGet into small, blunt granulesHigh-traffic locations, doors
LaminatedHighPieces stay bonded to interlayerGround flooring windows, burglary avoidance
Acoustic LaminatedHighSafety plus sound decreaseHigh-security urban areas

Boosted Locking Mechanisms and Hardware

A window is only as safe and secure as its locking mechanism. Secondary glazing includes a secondary physical barrier that a trespasser need to bypass. Since the secondary unit is installed on the internal side of the main window, it is shielded from external tampering or the use of prying tools.

Multi-Point Locking Systems

For bigger moving or sash units, multi-point locking systems can be used. These engage the frame at a number of points simultaneously, making it virtually impossible to jemmy the sash open. These systems are normally operated by a single, ergonomic deal with, ensuring convenience does not come at the expense of safety.

Protect Catches and Fasteners

Even for smaller systems, such as horizontal sliders or lift-out panels, producers use robust catches. Spring-loaded catches and fitch locks guarantee that the panels are held firmly within the frame, preventing them from being raised or moved by unauthorized individuals from the exterior.

Key-Lockable Handles

Adding a key-locking feature to the secondary glazing supplies an extra layer of defense. In commercial environments or rental residential or commercial properties, this ensures that unauthorized persons can not open the windows, which is particularly useful for managing ventilation or preventing falls in skyscrapers.


Fire Safety and Egress Considerations

While security is vital, the ability to exit a building quickly in the event of an emergency situation is similarly vital. Secondary glazing must be designed to comply with local structure guidelines concerning fire escape.

Quick-Release Mechanisms

For windows designated as fire leaves, secondary glazing units must be quickly operable without the need for specialized tools or secrets (unless those keys are kept in a known, available place).

  • Egress Hinges: Casement secondary glazing can be fitted with 90-degree egress hinges, permitting the unit to widen enough for an individual to pass through.
  • Easy-Slide Panels: Horizontal sliders are frequently created so that panels can be rapidly moved to one side or entirely raised out of the frame in an emergency.

Fire-Rated Secondary Glazing

In particular business or commercial applications, fire-rated glass might be required. This specific glass can withstand intense heat for a specified period (e.g., 30 or 60 minutes), avoiding the spread of flames and smoke through the building.


Child Safety and Fall Prevention

In multi-story buildings, secondary glazing functions as a crucial safety barrier to prevent unexpected falls, specifically involving children.

Opening Restrictors

Opening restrictors are hardware parts that limit how far a window can be opened. Normally restricted to about 100mm, these gadgets enable fresh air and ventilation while guaranteeing the space is too little for a child to crawl through. Many contemporary restrictors are "hidden," implying they are developed into the frame for a cleaner aesthetic, and can be disengaged by an adult for cleaning or fire escape.

Security Lists: Key Safety Features to Look For

When picking a secondary glazing supplier, homeowner should make sure the following security features are discussed:

  • Standard Compliance: Does the glass satisfy BS EN 12150 (Toughened) or BS EN 14449 (Laminated) standards?
  • Handle Ergonomics: Are the deals with simple to grip and operate for those with restricted mobility?
  • Interlock Gaskets: Do the sashes interlock when closed to prevent the glass from being pressed through the frame?
  • Sub-Frame Strength: Is the timber or aluminum sub-frame securely anchored to the primary masonry to prevent the whole unit from being required out?

The "Double Barrier" Effect

Beyond specific functions, the sheer existence of secondary glazing provides a mental and physical "Double Barrier." A trespasser looking at a house with single glazing sees a single, vulnerable pane of glass. If they see secondary glazing installed behind it, they understand they have two different systems to permeate.

The air gap in between the primary and secondary window likewise functions as a buffer zone. In case of a heavy effect, the external window may break, however the secondary window-- frequently made of stronger, laminated glass-- stays undamaged, preventing entry and maintaining the structure's envelope.


Table 2: Safety Benefits Summary

FeatureMain Safety BenefitSecondary Safety Benefit
Laminated GlassRobbery deterrenceUV security (prevents fading)
Opening RestrictorsChild fall preventionManaged ventilation
Internal InstallationTamper-proof from the outsideSecurity from the elements
Aluminum FramesStructural rigidityFire resistance (non-combustible)

Frequently Asked Questions (FAQ)

1. Does secondary glazing make it more difficult to escape in a fire?

If created properly, no. Standard setups for emergency exit paths consist of "egress" windows or easy-to-operate sliders that satisfy building safety codes. It is important to inform the installer if a window is a designated fire escape.

2. Can secondary glazing be fitted with locks?

Yes. Most secondary glazing units come with various locking choices, consisting of threaded bush locks, key-locking manages, and security bolts to boost home security.

3. Is it possible for a kid to open secondary glazing?

While older kids can operate manages, the setup of opening restrictors can limit the opening range to a safe width, avoiding falls while still permitting airflow.

4. How does secondary glazing secure versus required entry compared to double glazing?

Secondary glazing is installed internally. This suggests a trespasser must initially break through the main window and then handle a 2nd, entirely different locking system and glass barrier. Frequently,  secondary double glazing near canary wharf  and time needed to break through both are adequate to discourage a criminal.

5. Is the glass in secondary glazing constantly "shatterproof glass"?

Not always by default, however respectable business will utilize toughened or laminated glass as standard for bigger units or locations where safety is an issue. Constantly specify that shatterproof glass is needed when getting a quote.


Secondary glazing is a multifaceted solution that uses far more than simply a quieter, warmer home. Through the strategic usage of laminated and toughened glass, robust internal locking hardware, and thoughtful egress style, it substantially upgrades the security profile of any structure. For those living in older residential or commercial properties or high-crime areas, the addition of secondary glazing represents among the most efficient and least intrusive security upgrades offered on the marketplace today. By focusing on the particular security features detailed above, homeowner can ensure their environment is not only comfortable but likewise safe and compliant with contemporary safety standards.