Foster & Partners’ Stefan Behling discusses the current state and future direction of the architectural glass market
From an architect’s point of view, what do you feel is the key issue in architectural glass?
SB: “The first thing I’d mention is the size of glass sheets. Manufacturers and processors should be capable of supplying much longer standard sheets than are commonly available. Today’s jumbo panes typically measure about 3×6 metres; the new ‘standard’ could be 3×12 metres. The float line in a glass manufacturing plant can allow any length of glass to be produced. It’s the handling and processing of super-long glass that requires additional investment and planning. Companies that are taking the lead in this area include Pilkington, Saint-Gobain, Interpane and especially glass processor Sedak.”
Where else can you see room for improvement?
SB: “The next issue is quality, both in terms of glass coatings and product transparency. Taking coatings first, these need to be improved to preserve the visual neutrality of glass. Architects generally favour low-iron glass because it has the clearest appearance, but it is often sold as a premium product. In reality, this should be represented as the base or standard level, ideally with ‘invisible’ coatings applied to the glass that do not affect its aesthetic appearance.
Anisotrophy is a constant bone of contention on construction projects – in which properties differ according to direction. There should be common codes or performance scales relating to issues of flatness, iridescence, pattering, etc. Eckelt, for example, employs specialised equipment that allows architects to get a truer picture of how the glass will look and establish benchmarks.”
What are the principal areas of glazing development and what could these mean for architects?
SB: “In terms of innovation, electrochromic glass currently represents a significant area of development and interest. Switchable glass systems can be used for solar shading and privacy, and in combination with OLEDs, have the potential to accommodate advertising and moving images. Future intelligent glass facades could be touch-sensitive like the screens on our smart phones. Foster & Partners has not yet employed electrochromic glass due to the limited size of panels – typically one-metre square. However, we expect sheets of 1.5×3 metres to be available in around a year’s time.
Another area of growth is transparent structural silicone adhesive (TSSA). A wide range of products has already been developed, with Dow Corning among the industry leaders. TSSAs are set to have major impact on glass design, particularly in terms of facades, staircases and balustrades. It’s an exciting time for architects!”