The construction industry in the USA has enjoyed many years of enormous growth. New projects are springing up like mushrooms. They range from spectacular skyscrapers to efficient airports and stateof-the-art stadiums. And, even though it is as yet impossible to quantify the aftereffects of the coronavirus crisis: The USA is the land of (almost) unlimited architectural possibilities.
The Glas Trösch Group sees this as an opportunity to step up the exploitation of its immense coating technology and glass construction know-how in new projects. The Swiss family-owned company can already point to numerous prominent reference projects, among them the Soldier Field Stadium in Chicago, the Space Needle in Seattle and the New Whitney Museum in the Big Apple. Below we present a number of particularly spectacular glass solutions in greater detail.
The list of booming cities is topped, as you might expect, by New York. The number of skyscrapers planned there is impressive: More than 20 with heights in excess of 200 metres (700 feet) are currently under construction; dozens more are at the planning stage. Progressive densification means however that the task of finding extensive parcels of land without incurring cost-intensive demolition work is becoming ever more difficult. This has led to a new trend: skybridge structures. By way of example, since 2018 the somewhat linear New York skyline on the bank of the East River has been interrupted by a striking pair of high-rise buildings. The two residential towers of the American Copper buildings are reminiscent of two slightly reclining dancers, linked together for eternity by a glass bridge around 100 metres above the ground. Even by New York standards, this striking building ensemble, designed by SHoP Architects for the developer JDS, is unusual both in terms of its design and the actual materials employed. As a central design element, the skybridge not only has a purely aesthetic function, it is also structurally relevant and in addition, connects the building services of the two towers.
The highest bridge in New York
Whereas the facade cladding of the 41 and 48-floor skyscrapers is made up of copper panels, the linking bridge is clad entirely in shimmering, metallic finish glass, forming an elegant contrast to the two towers. What is already impressive from the outside is equally as remarkable from within. In the skybridge which is open to all residents are a spacious lounge, a fitness studio with bar and a hamam. The highlight remains the lap pool, which allows you to swim from one American Copper Building to the other while overlooking the city. Floor to ceiling windows provide uninterrupted views of the East River and Midtown Manhattan skyline. Stringent demands were inevitably made for the glazing supplied by Glas Trösch. A double insulating glass was developed for the unusual project in conjunction with McGrory Glass. This glass not only ensures uninterrupted views, but also satisfies the stringent energy requirements.
The curtain wall glass facade encloses all three floors of the skybridge and makes for maximum panoramic outlooks. The secret: a shimmering metallic gauze is bonded into the outer laminated safety glass. This gives the facade an elegant yet unobtrusive sheen. The filigree mesh openings of the gauze allow plenty of daylight into the structure, but also offer basic solar protection. In combination with LUXAR anti-reflective glass from Glas Trösch, the pane structure also ensures internal visibility and transparency. It is glare-free, and even more importantly, low in the level of reflectance, even in the dark. The overall reflection value is just two percent, which not only enhances the view but also serves as a protection from bird strikes. The additional coating SILVERSTAR SELEKT meets all the energy requirements and offers optimum solar and heat protection as well as high daylight efficiency. The figures speak for themselves, with a total energy transmittance of 26 percent, a Ug value of 1.1 W/m2K and a light transmittance of 44 percent.
Lobby work in Chicago
Many high-rise buildings are at the planning stage, not just in New York, but also in almost all other major US cities. Even cities that tended to occupy lower places in the highest buildings rankings have big plans: These include Los Angeles, Miami, Seattle, San Francisco as well as the fastest-growing metropolitan region in the USA, Austin, Texas. Occupying top spot in the competition for the most attractive and highest skyscraper is as expected Chicago, well-known for its trailblazing architecture. A showcase project for vertical expansion is the 228 metre high office tower at 150 North Riverside planned by Goettsch Partners and completed in 2017.
The skyscraper arose on the bank of the Chicago River at a point where several underground railways intersect, forcing the planners to get by with a restricted footprint. Their approach: extremely compact elevator cores and a complex structure supported by the building core made it possible for the skyscraper not to taper upwards in the conventional way, but rather to become narrower towards the base. As a result, the tower stands on a very small foundation in relation to its overall height and volume.
The ground floor of 150 North Riverside accommodates a 30-metre high lobby. As the facade tapers inwards towards the ground, the resulting enlarged space is furnished with a totally transparent curtain wall. Glas Trösch’s antireflective LUXAR coating was employed here, in this case as heat strengthened laminated safety glass. The clear transparency and colour neutrality of this glazing blurs the boundaries between indoors and outdoors and opens up the view of the adjoining buildings and park-like outside space.
Even before construction began, the Chicago architects Goettsch Partners were awarded the LEED certificate in gold for their concept. This ranking was assured on account of the building’s high energy efficiency, “green” roofs and high utilisation of daylight. In addition, the building has been accorded numerous awards, including the Award of Excellence of the Council on Tall Buildings & Urban Habitats.
A new face on New York’s Avenue of the Americas
Many US skyscrapers are now getting on in years – not only from an energy perspective, but also in design terms. Against this background, the modernisation market is playing an increasingly important role, also for Glas Trösch. The best example of a successful building refurbishment is 1221 Avenue of the Americas in New York. With its 50 floors, the office tower ranks among the tallest buildings in the city. It forms part of the so-called “XYZ buildings”, designed in the international style in the 1960s and 70s as an expansion of the Rockefeller Center. However, the former reception area on the basement floor appeared dated and over-bearing: dark red terrazzo, Levanto marble and massive columns were the characteristic features of the lobby. The building owner and architects felt it was important to lift this mood and create a bright and welcoming ambiance.
During the sweeping redesign, all materials no longer needed for the new concept were stripped out. The refurbishment involved not only the ground floor facade, but also the interior. While the fully-glazed frontage opens up new lines of sight, the interior stands out for its reduced colour scheme and use of sophisticated materials such as terrazzo and marble. Gleaming white dominates the interior, a concept enhanced by a dramatic lighting scheme.
With its bright and inviting design, the office building’s new lobby creates a smooth transition between inside and outside. To achieve this, 5×2 metre panes of glass were mounted on a slimline post and beam construction over two levels in the form of a curtain wall. Viewed from the front, few of the nine-metre high facade’s constructional elements are discernible. The properties of the glass facade were an essential design aspect in the planning of the lobby. Characteristics such as size, light transmission and colour were crucial in the choice of glass. During the planning phase, a mock-up was built in order to bring the properties of the glass better to life.
SILVERSTAR EN2plus from Glas Trösch satisfied the requirements for a high quality glass with the desired characteristics. The high colour rendering index and low reflectance of this insulating glazing in addition to the properties of the highly transparent EUROWHITE NG basic glass contribute to an exceptionally colourneutral appearance. SILVERSTAR EN2plus also offers an efficient and energy-saving solution: a low Ug value of 1.3 W/m²K provides for an effective reduction in heating energy costs.
Secretive glass facade in the Spymuseum Washington
For most architects, cultural buildings rank among their favourite projects. Hardly surprising, since they generally allow planners the greatest scope for creativity and freedom. Compared to skyscrapers however, they are rarely impressive for their height but much more for their unusual shape, fascinating floorplans or perhaps for their out-of-theordinary facades. The last-mentioned also applies to the recently completed Spymuseum in Washington DC, planned by the London architects Rogers Stark Harbour + Partners, whose co-founder Richard Rogers was involved in the renowned Paris museum building, the Centre Pompidou.
The Spymuseum is part of the masterplan for the L’Enfant Plaza in the south-west of the US capital and creates a new home for a private collection, formerly housed in a 19th century building. Inspired by espionage technologies, the complex facade plays with transparency and opacity, with the result that to the outside observer, the activities inside the building appear especially “secretive”. The most striking features are the sloping facades of the exhibition floors on the south and west sides of the building, enclosed in a type of “black box”. This is accentuated by bright red steel beams as well as by a folded glass curtain on the west side.
SILVERSTAR SUNSTOP Neutral 70 was used in the curtain wall. The special glazing from Glas Trösch stands out for its low total solar energy transmittance (g-value) of just 50 per cent, effectively preventing undesirable heat build-up with this expansive glazing. Nevertheless, the light transmission is a good 63 per cent and the heat transfer coefficient 1.1 W/m²K which in turn helps thermal protection on cold winter days. Alongside these technical values, it was above all the relatively neutral, light gray colouring that made this glass solution the right choice for the Spymuseum.
Retail glazing in popular shopping streets
Colour neutrality is also in particular demand in another quite different glass application area, the retail sector. This segment also ranks among the success stories in almost all major US cities – even though it is currently suffering severe setbacks due to the Coronavirus pandemic. For brand manufacturers in the top locations of cities such as New York, Chicago or Los Angeles the essential motto is: Don’t do things by half-measures. Size matters, and that also increasingly applies to shop front glazing. Here too, Glas Trösch has convincing answers with large pane dimensions as well as with nonreflective and colour-neutral glass solutions.
The ideal basis for shop front is the highlytransparent float glass EUROWHITE NG which has a light transmission value of 91 per cent. It thus not only guarantees markedly more light transmission than conventional glasses; it is also characterized by the absence of green hue and thus appears particularly clear and colour-neutral. The neutral appearance is also confirmed by the significantly improved colour rendering index (Ra), a measure of the glass’s relevant tendency to distort natural colours for the human eye. EUROWHITE’s high colour authenticity enables aesthetically appealing facade design with maximum colour neutrality. Optimum colour neutrality and high transparency is retained even during processing into laminated safety glass (LSG) with large element thicknesses. Moreover, the overall impression on the building remains homogeneous, even when using different glass thicknesses.
An example of successful shop window glazing in terms of design and technology: the Dolce & Gabbana Store on New York’s 5th Avenue. Here high-efficiency insulating glasses from Glas Trösch measuring up to nine metres in height were used on the facade. These afford passersby a largely unobstructed and colour-authentic view of the display in the shop window. Similar glazing is currently being installed at 299 Park Avenue. Other projects have already been realised. Among those in Rodeo Drive Los Angeles, Michigan Avenue in Chicago and elsewhere.
As a family company with more than 6,000 employees, the Glas Trösch Group has more than 100 years of experience both in the manufacture of glass products and in the development of structural glass components. A strong partner has recently been acquired in the form of BGT Bischoff Glastechnik AG with whom numerous international projects – in the USA among others – have been realised. Glas Trösch is driven to develop solutions that satisfy the most challenging aesthetic and technical demands. The implementation of projects of this type calls for courageous developers and architects. As can be seen from the examples, this is something the land of (almost) unlimited possibilities is also renowned for throughout the world.
This article was originally published in IGS Magazines Summer 2020 USA Special Edition: Read the full Magazine here for more thought-leadership from those spearheading the industry
Fabrice has been working in the marketing sector for 20 years and has held leading positions in the marketing team of the Glas Trösch Group for ten years. For this, he brought with him an education as a federally certified marketing planner and marketing and sales manager of the HSO Lucerne/St. Gallen in Switzerland. At the Glas Trösch Group, he was responsible for the restructuring of the marketing department and directed it until 2018. During this time he has made a significant contribution to shaping the national and international image of the Swiss familyowned company. Since 2019 Fabrice has been Creative Director of the Glas Trösch Group and in this function he concentrates on the development and implementation of innovative marketing concepts with a focus on international projects.