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Cesar Pelli & Associates: “The Art of the Wall” with laminated glass

An interview with Lawrence S. Ng, AIA, RAIC,
Associate Principal, Cesar Pelli & Associates, New Haven,
Connecticut, USA.

Canary Wharf, London, East Winter Garden roof.

Established in 1977, Cesar Pelli & Associates employs 80 persons at its offices in New Haven, Connecticut, USA and New York. The firm has designed major public spaces, museums, airports, laboratories, performing arts centres, academic buildings, hotels, office and residential towers and mixed-use projects. It has been the recipient of many awards including the AIA’s Firm Award in 1989.

Canary Wharf, London, East Winter Garden wall detail.

Lawrence S. Ng joined Cesar Pelli & Associates in 1981. Since that time, he has served as Project Manager and Design Team Leader for the architectural design and master planning of more than 40 million square feet of large-scale commercial developments.

Mr. Ng recently completed the design of four million square feet of new office development and public spaces at Canary Wharf in London including Citigroup Centre, the new headquarters buildings for Lehman Brothers and Northern Trust, East Winter Garden and West Winter Garden at Heron Quay. He is currently working on the master planning of an additional 3.2 million square feet of future development at Canary Wharf and is firm’s Project Manager and Design Team Leader for the 250-meter tall Torre Mutua in Madrid, Spain.

Mr. Ng also served as the Project Manager for the International Finance Centre in Hong Kong, the Petronas Towers and Dewan Filharmonik Petronas in Kuala Lumpur, Malaysia. At a height of 452 meters, the Petronas Towers was designated as the tallest building in the world at its completion in 1996. Other projects on which Mr. Ng has served as Project Manager include the 280-meter tall Cheung Kong Center in Hong Kong and the World Financial Center in New York City. He also served as Design Team Leader for the 237-meter tall One Canada Square at Canary Wharf in London.

Mr. Ng received his Bachelor of Architecture degree from Cornell University in 1978, his Masters degree in Architecture from Yale University in 1984, and his Master of Science degree in Real Estate Finance from New York University in 1996. He is a regular guest lecturer at Yale and Cornell Universities, where he lectures on international architectural practice and the design of tall buildings.

International Financial Centre, Hong Kong.	Cheung Kong Center, Hong Kong.

Laminated Glass News: What is important to Cesar Pelli & Associates as architects? Are there some main themes that you would say pervade the firm’s projects?

Lawrence Ng: The architecture of Cesar Pelli & Associates is about context. We believe architecture is an art of response, a creative and artistic response to tangible variables such as the client’s requirements and site conditions, to intangible variables such as the culture and value of our time, and most importantly, a response to the spirit and culture of the location. Each project requires a thorough understanding and analysis of all these variables affecting the design. Every project is a unique response to a specific set of requirements and conditions. As a result, the formal output of our firm is diverse and never conforms to any preconceived notions of style.

For example, our design for One Canada Square in London does not look like our design for the Petronas Towers in Kuala Lumpur - despite the fact that they are both clad in stainless steel and glass - because the physical environment and the cultural context are utterly different in these two locations. Similarly, our design for the Cheung Kong Center does not bear any resemblance to our design for the International Finance Centre, despite the fact that both are located in Hong Kong, because the specific site conditions are very different and, just as important, the client aspirations for these two projects were very diverse. The Cheung Kong Centre, located between two “form active” buildings, the Hong Kong Bank and the Bank of China, was designed to be understated yet elegant and assertive, with its own distinct identity. The International Finance Centre, situated at a prominent site by the harbour and at a height of 422 metres, was required by the client to be a landmark building that enhances the skyline of Hong Kong.

An important element that defines the spirit of a place is the quality of its natural light. The exterior wall surfaces of a building are rendered by sunlight; the color and atmospheric quality of the rendition are unique to its specific locale and they change with the seasons and the time of the day. This unique sense of place is very important to our architecture. The exterior wall of a building is therefore an important consideration in our work. One could call it “The Art of the Wall” because the exterior wall is the medium that arbitrates the relationship between the exterior and the interior, between natural light and artificial light.

Laminated Glass News: How does the use of glass help you to achieve your architectural design goals?

Lawrence Ng: The development of high performance glass coating technology has allowed architects to design in a higher degree of transparency for the building façade without compromising energy efficiency or the comfort of people inside the building in terms of heat build-up or glare.

As recently as 1997 our firm was designing buildings in North America, using low-E coating double-glazing products with a solar factor g-value of 0.32 to 0.27. Alternatively, we use a ventilated double wall, which allows us to achieve an even better solar factor g-value of 0.14 to 0.18.

These technologies allow us to use floor-to-ceiling, ‘vision glass’ panels. The glass panels give both extensive views to the exterior and minimal distortion for those inside looking out. This is a good example of a glass technology that is allowing architects to redefine a whole new relationship between the interior and the exterior.

Laminated Glass News: Why does your firm use laminated glass so pervasively?

Lawrence Ng: Laminated glass is a very versatile building material. It can achieve maximum size with minimal weight. It is not only a good material, but also a reliable material that satisfies a wide range of safety code and security requirements.

Laminated glass also has an excellent ability to resist impact load and it has very desirable post-breakage behavior. Unlike toughened glass, with laminated glass one does not have to worry about the potential risk of nickel sulphide and exploding breakage.

Canary Wharf, London, West Winter Garden.

Laminated Glass News: Could you please tell us about some of your projects worldwide that use laminated glass in an innovative way – for example, to refine “The Art of the Wall”?

Lawrence Ng: “We used laminated glass at the inner lite of the double glazing units for the exterior curtain walls at all of our six recent projects at Canary Wharf in London. One of the main factors in our decision to use a laminated assembly was to minimize the danger of people getting hurt by shattered glass in the case of a bomb blast. (It is a sad but well-recorded fact that flying shards of glass are among the most lethal causes of injury following a bomb blast, causing a greater number of injuries statistically than falling debris, for example).

For example, laminated glazing is extensively used on the entire exterior enclosure of the two Winter Gardens we recently completed at Canary Wharf. The East Winter Garden is highly sculptural in character, with a laminated glass barrel vault roof rising to a height of 28 m enclosing a grand space that is essentially an urban room. This will function as a welcome retreat for workers at the Wharf or as a setting for informal concerts, performances and other gala events. Laminated glass is used at the roof skylight and the cantilever glass walls at the north and south façades.

The West Winter Garden, in contrast, is a simple abstract glass box, measuring 28 m x 28 m in plan and 16.50 m in height. Its structure is light and elegant; it functions as a passive retreat for workers at the Wharf. In the West Winter Garden, the use of laminated glass meant that we could incorporate 2,700 mm x 2,700 mm double-glazing units at the roof skylights, maximizing transparency.

In the design of the exterior enclosures for all our recent buildings at Canary Wharf, we worked closely with some of the best engineers in the curtain wall industry today: Permasteelisa, Scheldebouw, Gartner and Seele. We also have ongoing dialogues with major glass companies, such as Saint Gobain, Luxguard and Interpane regarding their products.

In both the Canary Wharf Winter Gardens, the use of laminated glass also allowed us to achieve a whole spectrum of aesthetic effects including: varying degrees of luminosity; transparency and translucency; opacity; reflective opacity; decorative patterns and so on.

In the interior design of the Winter Gardens we wanted to fully exploit the beauty and the aesthetic possibilities of glass for a wide range of applications. This was made possible by the use of laminated glass. For example, we designed glass stairs and glass floors encased within a glass pavilion; internal lit glass benches; glass wall panels and glass railings; ceiling light fixtures and art glass walls, all incorporating laminated glass constructions.

Canary Wharf, London, East Winter Garden.

As internal atria now constitute a common architectural feature, the use of laminated glass for the surrounding glass balustrades is especially important, in my view. Most building codes specify the use of safety glass – but that can mean either toughened glass or laminated glass. Toughened glass would pose the risk of potential exploding glass balustrades and falling glass shards causing injury if the heat soaking process is not done properly. The British Standard, for example, requires toughened glass be heat soaked for eight hours at 290 degrees C.

In our current design for the Torre Mutua in Madrid, Spain we are exploring the potential of using photovoltaic cells in a laminated assembly in the roof feature that will generate heat for domestic water. Spanish law has recently changed. Since November 2003 all commercial buildings have been required to use solar power to generate hot water. So the need for photovoltaic constructions encased in laminated glass on the rooftops of commercial buildings in Spain will undoubtedly increase.

Laminated Glass News: What do architects want laminated glass to do for architecture in the future and what will take to get there?

Lawrence Ng: Society as a whole is more aware today of environmental sustainability issues. We not only want our architecture to be beautiful, we also want it to be environmentally responsible. There is also a much greater focus on the comfort of the working and living environment not only in terms of thermal comfort but also visual comfort. There is a stronger emphasis on integration between the exterior environment and the interior environment. We expect future developments in laminated glass technology will help us to better achieve these aesthetic and functional objectives.

As a general rule, I believe that architects today are more involved in the production and fabrication processes of building materials. We go to glass factories and witness first hand the coating process, the laminating process, the ceramic coating process and so on. We want to understand the technological feasibilities, limitations and possibilities of the materials we are using.

In turn, this has come to mean that as architects we participate much more in product development process than in the past. We are also more aware of emerging technologies – specifically new glass technologies - and the expanded design possibilities posed by these technologies. There is a greater collaboration between the architect and the engineers in the construction industry - this is particularly true in Europe.

At Cesar Pelli & Associates we believe these trends will continue. There will continue to be a greater synergy between architects and the engineers involved in the curtain wall industry and the glass industry. This in turn will mean that the glass industry will get involved earlier on in the design process.

Similar to the great stone craftsmen of the Renaissance times and the glass artisans of the Gothic period, glass industry people are among the most prominent of the modern day craftsmen making great architecture possible today and in the future.