Window Bar Security Grilles, London
Specialist Window Security Grille Manufacturers & Installers Since 1974


The usually static and ultimate grille solution for protecting windows and other vulnerable entry points from burglars, window bar grilles made from solid steel are the most commonly known type of security grille used to prevent unwanted access and break-ins to your property.

If you are unsure if they're usage and features are right for you then try check out other types of security grilles and gates where you can find a variety of ways to protect your windows and doors.

Manufacturing and Installing Bar Security Grilles

Standard design approaches for manufacturing and installing security bars consider the purpose, placement and type of building. For example whether it's installed inside or outside can affect the types of fixings we use, if it's residential then aesthetics are of concern, and when installed for commercial buildings then insurance or safety requirements can be quite particular.

Whichever the case may be, trying to discover what your options are can be a confusing place to start.

Bar Grilles are becoming a common standard for windows in many parts of the UK, and we have some common types which are used for the majority of installations. Here, we cover the general materials used along with some fixing methods to suit each requirement.

Keep in mind that hinged and removable facilities can be added to window grilles, but you may also want to check out collapsible gates, a specific retractable type of security gate for windows and doors that offers great functionality for this purpose.

Demo Examples

Security bar grille in London basement with decorative artwork.

Basement Window Bars

As with all windows, using bar grilles to secure basement windows is a very popular and appropriate choice. Without using stock strap with fixed hole distances for each bar to pass through, the spacing between bars is divided evenly based on the window width. Then, each scroll as show in the image is made to suit these calculated spaces on a per window basis.

Security window bars in London. Bar grille with arrow heads.

Decorative Outside

You can improve the appearance of bar grilles by adding ornamental features and using a smaller bar diameter. Outdoor features often differ from indoor as shown in the image, but railing heads are a simple and effective way to add style to security bars.

PHR security grille in London. Window bar grille for burglary prevention.

Decorative Inside

Using square bars and flats to generate decorative patterns make for an easier appearance when installing bar grilles inside. When making grilles that open, a padlock is often suitable for indoors. They are versatile for frequent changing of keys, but not always as secure as other methods of locking.

Bar grille in London with ventilation gap bars for window.

Security Grilles & Ventilation

Where ventilation is important for a building that needs security window bars, you can have the gap between the window and grille increased to allow windows to open and ventilate. This is commonly known as a 'stand-off' measure.

Bar grille in London Basement Bay Window.

Basement Bay Window

Security Grilles for Sash Windows protecting a London basement property, common in London areas and particularly vulnerable to attack.

Bar Grille in West London fixed window bars for security.

Alternative Fixing

When there's no option of fixing into the side (reveal), fixing bars into the face of the brickwork is done using bolts or other type of heavy duty fixing.

Window bars to stop children falling out of window.

Child Safety Window Grilles

To prevent children or pets from falling out the window, bar grilles can be a great safety choice to provide restriction and peace of mind. They can sometimes become cheaper than security grilles because less material is required to account for both increased security and window coverage.

Georgian style security bar grille fitted to window in West London.

Georgian Grille Design

Most sash window styles can work well with simple georgian styled window bar grilles as they blend well with the overall feature. Using a smaller flat or square steel bar keeps the thickness within beading sizes and still provides a reasonable level of protection. This is a good option for childrens bedrooms when safety from falling is a concern.

Security bars for window with fire escape for window bars in London.

Safety Escape Route

To secure a window or opening in a building while maintaining it as an escape route for fire and safety, a bar grille built with a hinged section and a lock and key provides both a practical and strong solution. A key can be kept close to the grille either in a safe place, or to comply with a safety regulation a 'break glass' box can be screwed to the wall.

Types of Window Bar Security Grilles

Higher Security Types

These are the typical window bars that are often fitted externally and made from thicker materials. A round shaped vertical bar of 20mm diameter is used as standard and it passes through a horizontal 'strap' which can be either 40mm or 50mm wide by 10mm thick, where 50mm strap offers more strength when the overall grille is wider. A round bar reduces the grip for wrench type tools to prevent twisting the bar to break the grille. Each bar is then fully welded across the top of all straps to secure its position.

Challenges for External Bars

Particularly vulnerable to initial attack when installed outside, special protection is added to fixings to protect them from tampering. Bolt heads are secured as shown by one method in the image.

For fixing heavier types of grilles a good option is the 'pin and tube' method. Whilst it is a heavy duty type of fixing which is not as subtle as bolts or screws, it makes up for its applied popularity in strength. A 20mm hole is drilled into the brickwork and a steel pin is hammered into this hole, passing through a tube welded to the grille. It is the most robust form of fixing that causes least disruption to the buildings masonry. A demonstration can be seen in the video.

Protected Bar Grille Bolts in London Basement

Lighter, Internal Styles

There can be many reasons for fitting window bars internally, and causing least disprution to the architectural design flow is one of them. Maintaining features can be of concern for listed type buildings, and also for buildings aligned in streets that conform to a uniform style of design, which is common in London and other major towns and cities.

Standard lighterweight bar grilles are typically made of steel flat straps and square bars. These materials help blend in with existing building and window patterns.

Georgian Bar Design

With window transoms, mullions and beadings arranged into squares patterns within a window, georgian styled steel bars aim to add to this arrangement by matching existing window bars and adding bars at measured points to maintain consitency in appearance. A good material for this is to use flat straps of 20mm x 6mm, but sometimes square materials can be appropriate.

Security Bar Grille Georgian Pattern for window in London

A Required Specification

As buildings and openings vary, so does security requirements and purpose. Security Grilles can be designed in any way feasible to suit a range of security and safety purposes, but categorisations of insurance specifcations can be quite specific.

As a general standard, spaces between each bar are made to be no larger than 127mm. This specification is recommended by crime prevention officers and insurance companies, for a number of reasons. It is not uncommon for this to change for aesthetic reasons, but it is an important factor which is always given a priority consideration when designing grilles for windows and openings.

With a wealth of experience, PHR offers best practice advice and undertakes work to comply with such cases. Feel free to contact us to arrange advice with this matter.

Finish and Costing

As with each of our security grille and gate categories, powder coating provides the best process for finishing the grilles. This results in a very durable finish which binds well to the steel and leaves a smooth result.

Prices displayed online for stock based grille solutions are misleading. It's easy to get a fast quote for a grille that is made for your window and provides precisely what you want at less of the cost. If you have measurements of your opening, then thats all you need. Provide these through our quote form and we will respond promptly with a realistic price that almost always never changes after survey.

Alternatively, give us a call!