As technology evolves, glass continues to be seen at the core of many exciting and iconic buildings, enabling achitects to achieve their goals. Phil Savage of Pilkington discusses the growing importance of glass in modern building design.
A look across UK’s big cities reveals a horizon peppered with construction cranes. From high-profile commercial office towers to prestigious residential developments, our skylines is changing fast. Architects continue to incorporate glass into their designs to make a statement in the built environment. Iconic buildings across the world, from The Louvre in Paris to London’s Gherkin, are a powerful example of the physical and aesthetic effect the material can have on the urban landscape.
The ability to create larger and more impressive glass structures over the years has developed in line with technological and engineering improvements, and arguably one of the most significant architectural innovations of modern times has been the development of structural glazing systems.
These enables architects to design buildings as if they are solely made of glass, allowing for more imaginative and visually striking alternative to traditional brick, timber or stew-reinforced concrete.
How it works
The structural glazing systems available on the market today typically work by using stainless steel fittings that are countersunk into recesses in the corners of the glass, allowing strengthened panes to stand otherwise unsupported. The glass is then fixed to the structure of the building itself, rather than being fitted within traditional and sometimes view-restricting frames.
With a range of options available, architects are able to choose the system that best suits the specific criteria of their installation and ultimately allows them to create their desired finish and performance. Glass-fin (mullion) units, for example, are among the most popular where a seamless finish is required.
The use of glass fins eliminates the need for traditional metal mullions, which can restrict the view from inside a building. The transparent fins support the vertical facade and provide additional strength and integrity against the elements. Stainless steel fittings hold the structural elements together to create a strong, secure building envelope without compromising on the transparency or the external view.
Added performance
As well as being a popular choice among architects for the aesthetic results it can create, structural glazing also offers a number of other benefits too. Advances in coating technology mean that glass can increase a building’s energy-efficiency, helping to control its temperature or reduce glare.
If the facade is south-facing, for example, solar control glass can help to prevent overheating inside a building, and reduce the expense of running air-conditioning units. Today’s technology also means glass manufacturers can now produce solar control glazing with very high levels of transparency, which allow maximum levels of daylight to be transmitted into the building without compromising on performance.
On the flip side, in colder climates where keeping buildings as warm as possible is a priority, structural glazing systems can employ the latest low-emissivity technology to achieve near-optimal thermal efficiency. The same system can also be double- or triple-glazed for even better thermal performance.
Not only does this maximise internal comfort levels but it also helps to reduce the cost of energy bills.
Redefining the potential of glass
Advancements in technology and improvements in engineering have meant the glass structures designed and built today are on a larger scale and are visually more impressive than ever before.
As we continue to see developments in this area of the built environment, and as glazing systems evolve with these changes, the material’s potential will continually be redefined for architects, and it will play a key role in the creation of high-performing, sustainable cities of the future.
The atrium of a commercial building is clearly one of its key selling points. It is often the building’s first impression with prospective investors, tenants and other visitors, so it needs to impress.
It was with this in mind that developer Boston Properties and architect Duda Paine Architects specified the 10-storey, almost 35-metre tall glass facade that fronts the atrium at its landmark 601 Massachusetts Avenue project in downtown Washington DC. The building is a substantial new visual statement in the capital that brings glass to the fore.
The objective was to create a wall of glass that delivered maximum transparency with minimum vertical elements, so that the whole atrium felt as much like an outdoor space as possible.
This was achieved using the Pilkington Planar point-supported glazing system to secure panes of up to 1.5 m by nearly 3.5 m of 12 mm Pilkington Optiwhite true low-iron glass to a series of 26 m-wide one-piece horizontal trusses spanning the atrium. Additional vertical support was provided by low-profile stainless steel tension rods. A total of 970 m2 of glass was used, weighing around 29 tonnes.
The low iron content of the glass means it has exceptional clarity without the pale green tint present in standard float glass. The clean lines were further enhanced by ensuring the glass was manufactured within extremely tight tolerances in terms of roller-wave distortion – the maximum ‘peak to trough’ variation allowed was just 0.02 mm, creating an almost perfectly flat surface to ensure undistorted reflections of the building’s surroundings.
The stainless steel bolts that connect the glass with the structure sit perfectly flush with the glass, maintaining the uninterrupted surface.
The multi-million dollar Massachusetts Avenue development features 44,400 m2 of high quality office space. The scheme has received Leadership in Energy and Environmental Design (LEED) Gold certification, demonstrating environmental responsibility across the design, construction, operation, and maintenance of the building.
Phil Savage is commercial sector manager at Pilkington United Kingdom