Professor James O’ Callaghan: We need a smarter glass that embraces innovation

Professor James O’ Callaghan, one of the keynote speakers at the 1st Glass Forum, talks about glass as a structural element and the need for the industry to move with the times through innovation and new technologies.
Interview with Alexia Kalogeropoulou

Dear Mr. O’ Callaghan, in the wake of the 1st Glass Forum Conference and your very interesting lecture, we realised that nowdays there is a very difficult and changing landscape for the glass. How can we use in a best day the glass in the future? And what technology might suggest for it?

It is clear that the world is facing significant challenges from climate change, we are often reminded of this with local extreme climate events, of which Greece has its share. To prevent these events increasing in severity and frequency we all need to do what we can to limit the increasing heat of the planet, that can only be done by reducing the amount of energy we draw from our primary fossil fuel sources. Glass has a pivotal role to play in this equation. It is the primary interface between the inside and outside of our buildings and its qualities in terms of the connection it provides us to light and the outside are now indispensable in architecture. Glass therefore must react to the increased performance put upon it due to a need to better control energy both through solar gain and thermal loss. If we do not find ways for glass to improve its performance in these critical areas we will be faced with reducing its area in our buildings and ultimately replacing it with more and more solid, highly thermally performing substitutes. This is not what we all want, it is regressing to an architecture we came from and not one we invented through modern glass fabrication. We are at a pivotal point in time in the role glass plays in the future of architecture.

Is it possible for the glass to remain transparent, while it becomes a strong and reliable structural element? And in which ways is this possible?

My work in the development of glass as a structural material has been evident in many projects, probably most notably through our work for Apple in their retail stores. These projects are widely seen as the worlds most ambitious and progressive uses of structural glass in order to achieve maximum transparency. In the development of these projects we focused on the connectivity of glass given the need to maintain maximum transparency while achieving the connections. If the connections become to visually intrusive the elegance of the glass structure is lost and its primary aim of transparency is compromised by the eye being drawn to the detail of the connection. While it is not only important to limit the connections in size and frequency to maintain transparency it is also very important to ensure that the connections design are particularly refined, with every mm of material being fully utilised. I think that this approach to structural; design is a good metaphor for all structural design where a more concentrated focus on ensuring maximum utility only services to use less material, which in itself is a highly sustainable approach to building structures.

With which other materials or supportive elements can the glass be composed? Is there an element that is not suitable for the glass?

Glass can be combined with many other construction materials. Clearly most others are not transparent which means the combination needs to be considered architecturally. We have experimented with using carbon fibre as a material that compliments glass because we can engineer particularly big spans with a lightweight material that glass can readily support structurally. We have considered ways in which wood can be combined with glass to introduce more bio based sustainable materials directly in contact with glass. These are all research ideas to an extent, but perfectly reasonable to imagine. Glass as a material is brittle and as such it cannot accommodate local pressure form hard materials, so we need to isolate glass from such materials when transferring loads and we need to ensure the surface area over which the load is transferred is enough to keep the local stresses below that of the glass failure strength. This is a key design parameter that is not limited to any one material but is more critical with some more than others.

During your lecture in the 1st Glass Forum Conference, you mentioned that managing light and energy is critical for the glass not only nowdays but also in the future. How can we manage this?

Until such a point that energy is entirely emissions free, glass will need to do more to reduce energy transfer into our buildings. Energy into our buildings means to have to cool them more to remain habitable and that requires significant energy. So we need glass to work harder, and that means innovations in the treatments we can apply to glass, technology we can combine with glass and architecture around the glass to ensure it continues to meet this demand. We need glass to be smarter, more like the skin of ourselves in how it reacts to its environment. Just like sunscreen changed our ability to experience the sun, we need a similar technology to allow our buildings to bath in the sun and not overheat.

You have already completed a lot of demanding projects concerning constructions. Which one was the most challenging and why? And how did you manage to solve any possible problem that came on the way?

I see all our projects as an iterative deployment of ideas and research that precede them and as such they have all had their challenges resulting in a thread of innovation. Built if I was to pick one, I think I would have to pick the first Apple Cube in New York. At that time in early 2005 we were just pushing hard on glass connection and lamination innovations with new materials and ideas with very detailed analysis required for us and our client to be confident that an glass building of this scale in this high profile location would be beautiful – and yet very safe. I think this was the most significant leap in structural glass at the time.

How you see the future in constructive glass in general? What it will be next? Are you planning a promising project for the future?

Glass is here to stay, it is a fundamental part of how we enjoy the spaces we inhabit. So there is a promising future for glass in buildings, I just see that it needs to move with the times and embrace the innovation that can support a wider application of it. It needs to be smarter, work harder, all the technology that is surrounding us will support it to do that. We need the industry to recognize that and encourage innovation such that the resulting products and applications really make the most of glass and ultimately the buildings in which we live, work and visit.

Professor James O’Callaghan
FREng CEng BEng FIStructE MHKIE, Founding Director, Eckersley O’Callaghan

James O’Callaghan is a world leading Structural Engineer widely acknowledged as an authority in the use, and design of structural glass. He is co-founder of the multi award-winning global structural engineering practice Eckersley O’Callaghan known for its pioneering and award-winning projects for clients including Apple, Google and LinkedIn to name a few. As Professor of Architectural Glass at TU Delft, James has a key role in establishing research in all areas of glass in architecture. This is helping to map out the use of glass in the urban fabric of the future and accelerate more sustainable and responsible solutions.