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James Carpenter: "Exploring the Dramatic Inter-Relationships of Glass and Light"

James Carpenter

James Carpenter's interest in architecture began at the Rhode Island School of Design, where he received a degree in glass sculpture in 1972. He then worked as a consultant for Corning Glass Works before opening his New York studio, James Carpenter Design Associates, in 1979. In 1991, the American Institute of Architects conferred its Institute Honor Award on James Carpenter as "an artist whose rare, unsurpassed technical expertise and sculptor's sensitivity have moved him to explore and express dramatic inter-relationships of glass and light that have become indispensable ingredients of great architecture". Mr. Carpenter has also been honored several times in the DuPont Benedictus Awards.

Laminated Glass News: Please tell us more about why you have chosen to focus on working with glass – and with laminated glass in particular.

A view from the south at mid-day, with inset detail from Carpenter's Dichroic Light Field, New York

James Carpenter: Glass is the only material that allows you to explore the natural phenomena of light – such as reflection, refraction, luminousity and transparency – as they influence architecture. Laminated glass gives us the design freedom to incorporate fairly large works of glass in public places safely and securely. Because of its safety and security aspects, laminated glass is generally mandated by the building codes for the type of work we do.

My over-riding motivation is to control light and allow glass to define the way light is perceived and in this sense, I find the edge condition of the glass just as interesting as the plate surface.

Using the lamination process, you can do remarkable things with the passage of light by 'sandwiching' up to 10 types of glass together with each layer possibly having a specific property and this gives a virtually limitless range of reflection and refraction possibilities.

Also interesting is the way the lamination process allows you to add other materials between the glass interlayers – whether it's a specialized type of photo-reactive film or another material.

LGN: Daylighting is an important theme for you. Tell us more about that.

JC: It is essential to maximize daylighting, both in order to reduce energy needs and to improve the interior environment, whether the project is a courtroom, an office building or a public atrium. When you start laminating panes of glass together, you can do more than just filter out UV. You can bend the light by use of prism. With 'ordinary' windows, sunlight passes through, is projected onto the floor and is absorbed by the flooring or carpet. By using prisms or other light re-projecting technologies within laminated glass (either by laminating prismatic forms to the outboard side or by fixing prisms within a double-glazed unit) you can redirect the sunlight to hit the ceiling and then re-reflect the light down into the room and illuminate the space much more efficiently. We often laminate glass in order to redirect the light in this way.

LGN: What are your views on energy control using glass?

JC: I believe that energy control using glass will be one of the most important architectural trends for the foreseeable future. Use of a single, tempered, double-glazed panel with a highly reflective coating rejects all the potential in the sun's energy – as well as producing hermetically-sealed, dark buildings with little or no natural daylight inside. Now, thanks to the properties of laminated glass and new, specialty coatings, we are learning to treat the surface of a building not just as one layer but as many surfaces.

In the Fresnel Ring (Rhode Island Convention Center); light is reflected and scattered on the walls and ceiling through the use of dichroic Laminated glass.

In many new buildings, transitional spaces like corridors that have no need to be artificially lit, heated or cooled, are being placed on the outside. In between the walkway and the offices there is then a performance window. In some respects, by creating these weather buffer zones and thereby having a greater surface area of glass, you need less energy to heat the building.

LGN: Your Dichroic Light Field in the Millennium Building in New York was honored by the 1997 Benedictus Awards. Could you explain to us how your dichroic system works and what you were aiming to achieve with this mural.

JC: Dichroic coatings consist of at least 14 layers of metal oxides, each one molecule thick, put in place through vacuum deposition, to selectively interfere with various wavelengths of light so that, as light moves, varying degrees of light are reflected and transmitted and the colors appear to change. We laminate the dichroic coating within the glass so that it is hermetically sealed because it is very, very fragile.

In the New York project, we wanted to create an illusion of light coming from within the building. Perpendicular to the wall, we have affixed a grid of laminated glass fins, each fin also having an internal dichroic coating, which are projected two feet into space and which enhance the overall effect of varying light, colors and shadows. It was only feasible to think of the fins in terms of laminated glass for safety reasons, since they are between 13.7m and 18.2m off the ground.

LGN: What kind of safety tests did you subject this project to?

JC: We had to consider long-term and instantaneous windloading and prove that the fins could bear two or three times the load specified in the building code. This application is situated in downtown New York but even if vandals shot at these quite large, heavy glass finds using a revolver and if both panes of glass were broken, they would stick to the laminate, without falling down an causing injury, until repair could be effected.

LGN: What were your design goals with the Refractive Glass Curtainwall in the First Hawaiian Bank in Honolulu?

The refractive glass laminated wall, First Hawaiian Bank, Honolulu

JC: This project offers an alternative approach to the challenge of building a curtainwall façade suited to a hot climate, using laminated glass both for safety and to encapsulate the thermal coating. The outermost layer of glass is clear, with a low-E coating sandwiched within it. Then there is a cavity for natural insulation/ventilation; the heat coming through the glass is trapped in a two-foot zone and since heat rises, the warm air is carried upwards and out through vents via a natural convection system to the outside. On the inner side of this cavity is a translucent layer of tempered glass.

The structure of the wall is notable for the size of the laminated glass panels which are around 2m tall by 500cm wide and which are stacked five high, giving a total height of almost 15m. The overall thickness of the laminated glass is 38mm. It contains a translucent layer of glass prisms which refract the incoming sunlight so that more daylighting is received into the building.

LGN: What were your design goals in the Hong Kong Convention Center and the Rhode Island Fresnel Ring?

The vertical laminated glass tower in the Hong Kong Convention Center

JC: At the Hong Kong Convention Center, we created a 21.3m high, laminated glass tower which acts as a marker for the building's entrance. The outer layer of the laminated glass has a diffused surface which gives a sense of translucency to the entire structure. This sculpture is unique in that it is a glass shell whereby all the glass elements are structurally bearing against their adjacent panes, creating a compressive skin.

The Fresnel Ring uses dichroic, laminated glass to use the light coming into the building and bounce it off the sculpture and onto the floor, so that the floor is illuminated in a very special, beautiful way, giving a pattern of interlocking rings of light and shadows. This piece really brings a level of animation to the public entrance of the Rhode Island Convention Center and again uses glass as a compressive member in the overall structure.

LGN: Could you tell us about some of your new projects?

JC: We're working on a laminated glass façade for the new German Foreign Ministry in Berlin with architects Muller/Reimann. The façade uses a sandwich of laminated glass to provide various functional benefits in redirecting daylight: for example, it contains a transparent coating that reflects around 20% of the light to optimize daylighting within the building. This project is due for completion in the year 2000. We are collaborating with the engineers Schlaich/Bergermann of Stuttgart on this structure, which is a pure cable-net concept. We are also working on a laminated glass ceiling for the main courtroom in Phoenix, Arizona with architect Richard Meier which will use clear and translucent glasses for optimal daylighting. This is another cable net structure, which we are working on this time with Ove Arup and Partners.

LGN: What do you believe the future holds for laminated glass in architecture?

JC: There will be much larger quantities of glass used in buildings, consisting of transparent and translucent glasses rather than colored and tinted glasses. Architects will employ more laminated glass because of the opportunities to include various films and prismatic devices to make our windows 'work harder' in terms of energy efficiency and daylighting. I believe that the research currently taking place into daylighting and its importance to productivity gains and people's general feelings of well-being is just the tip of the iceberg; daylighting will become even more important to architects in the next century than it is today.