It’s very easy, when you work in a niche industry, to forget that the terms we use on a daily basis can be a little baffling for our clients, or the general public. We’ve been working in the world of structural glazing for over 30 years - and while that might be second nature for us, we thought we’d put together a guide to explain exactly what structural glazing is. Where it came from, how it can be used, and why it’s such a crucial part of modern design…
What is structural glazing?
Simply put, structural glazing is term used to describe glass that is integral to the design of a building: It involves large glass panels, which usually bear some weight in the structure. Structural glazing can be used to create huge glass installations with minimal obstruction.
This is, of course, putting it fairly simply. There are myriad ways structural glazing can be implemented in a design - the most important thing to note is that we’ve come so far with glazing technology, glass can be used as a structural material in almost any situation.
It can bear weight both horizontally and vertically, and it can be bonded using everything from minimal glass beams and supports to heavy-duty steel struts, meaning it can be used on almost any scale, with almost any aesthetic imaginable. Everything from completely frameless sliding glass doors to load-bearing high-strength glass floors can be created.
The history of structural glazing
Glass has been an significant feature in British architecture since the late medieval period, from which time the use of glass windows has grown to a point of near universality. Structural glazing, however, is an far more modern phenomenon, which has made possible through advances in glass technology and building techniques. In contemporary architecture, due to ever-developing load-bearing potential, glass can be used in ways that would previously been assumed impossible and in wholly innovative projects.
So how was structural glass developed? As with many developments in production and technology, it’s a story of incremental progress overseen by a variety of manufacturers, engineers and architects, and one that still continues to this day. Perhaps the earliest example of structural glazing is glass block - developed in the early 1900s to bring more light into industrial spaces, this material is load bearing and used in a manner akin to masonry.
Within the last few decades, toughened or tempered glass has been increasingly used in frameless glass features, such as staircases, doors and load-bearing floors and walls. From here, glass lamination has created another level of safety within glass construction. In 2009, the Willis Tower in Chicago opened The Ledge, a transparent glass box which is held from the wider building by cantilevered steel beams - offering visitors a hair-raising (if completely safe) experience of load bearing glass at 1,353 feet.
In 2016, the Zhangjiajie Glass Bridge opened and took the title of the longest glass-floored bridge in the world, stretching 300m above a beautiful mountain valley. In order to prove the strength of the bridge and challenge the idea that glass is inherently treacherous, a car was driven across after one of the panels was hit with sledgehammers.
Apple’s corporate headquarters, affectionately dubbed “the spaceship”, is currently the largest glass-supported structure in the world, and Steve Jobs is considered a particular innovator of glass staircases.
Where would structural glazing be used?
Structural glazing is used extensively in skyscrapers, with glass facades a ubiquitous feature in the financial centres of cities across the globe. As we’ve seen with the Zhangjiajie Glass Bridge, it is also being utilised in situations where architects aim to make the most of extraordinary landscapes for the benefit of visitors. Chamonix’s Aiguille du Midi Skywalk, Austria’s “Stairway to Nothingness” and Canada’s Glacier Skywalk are all breathtaking examples of this trend.
However, structural glazing can also be included in personal homes in a variety of architecturally innovative and visually compelling ways. Glass extensions are being increasingly adopted by homeowners as a way of increasing space and natural light without the frames and limited structural possibilities associated with a traditional conservatory.
Strengthened, laminated glass can also be used in floors, roofs and frameless glass walls. This offers endless opportunities to homeowners and architects to create an open, light atmosphere while still organising internal spaces and providing shelter. As a material, glass can now be applied in the same way as many other building materials when it’s particular properties are taken into account, with architects and engineers continually finding new ways to take advantage of the vast design possibilities that structural glazing presents.
Why use structural glazing?
There are many benefits to using structural glass within a building, and perhaps the most compelling is the increase of natural light in our domestic and professional spaces. Throughout our evolution, humans have relied on daylight to regulate and enhance our circadian rhythms, and it has become clear that natural light is a vital part of our overall wellbeing. The time we spend in artificially lit or gloomy environments has a clear impact on our sleep quality, productivity and happiness.
Structural glazing can offer a greater coherence and connection between the natural world and our buildings, while still protecting us from the elements. It allows sunlight to flood a home without any attendant annoyances that have previously hampered glass structures, such as overheating and the subsequent loss of heat at night. In fact, advances in technology mean that insulation is actually one of the great advantages of using structural glass.
Rather than creating a greenhouse-like effect, thermal glass technology exploits the “solar gain” which can make glass spaces too warm to create a stable and comfortable ambient temperature which is maintained throughout variations in weather and the time of day. This is energy efficient enough to result in savings on heating bills, while also enhances the interior environment in a way which makes glass eminently practical as well as aesthetically stunning.
The inclusion of structural glazing also adds an element of modern luxury to any home - and there is a distinct advantage in the fact that glass can complement older and listed buildings in a way that does not compromise any historic value. Frameless glass, in particular, can be added to or within a building without obscuring original features.
Popular structural glass installations:
Sliding glass doors
Sliding glass doors are one of the most effective ways to create a seamless visual and practical bond between the interior of a building and the world outside. They are elegant, secure, and offer one of the most aesthetically striking ways to create an access point in and out of a home or commercial property.
A glass roof is the ideal way to flood the interior of a space with natural light, which is one of the most important benefits of structural glazing. Roofs can be fixed or opening, and they can even be completely frameless - offering a totally unobscured window to the sky above.
With structural glazing, there’s no limit to the size of a minimal window - meaning it’s even possible to create entirely glazed structural glass walls. These are instantly attention-grabbing, and can truly elevate the aesthetic of a property into a new dimension.
Minimal glass windows
Sometimes, the humble window is all that’s required in a design. With structural glazing though, the design and style of a glass window can be completely transformed. Minimal glazing can be utilised to create windows with frames that are almost totally invisible.
By combining a number of structural glass installations such as walls, sliding doors, and roofs, it’s possible to design entirely new sections for a property in the form of a structural glass extension. This is a hugely effective way to expand the available space in a home, with all of the added benefits of structural glass - and none of the draughty impracticality of traditional glazed conservatories.
How much does structural glazing cost?
Unfortunately, the answer to this question is difficult to specify. This is because structural glazing is inherently a bespoke solution - by using glass as a construction material, it’s necessary to design the glazing with the specific project in mind.
In general though, it’s understood that structural glazing is at the higher end of the pricing spectrum when it comes to building design. This is particularly true when opting for the high quality and specialist expertise of a company like Cantifix, but the benefits of this outweigh the money (initially) saved by opting for a more ‘budget’ competitor.