Extended Interview with Craig Schwitter

Craig Schwitter is a partner at Buro Happold Consulting Engineers (BH), and is a former SEAoNY Director. He has been a practicing structural engineer for over 17 years, and began the New York office of Buro Happold in 1999. He has worked on numerous sustainable building and planning projects in both the United States and the United Kingdom, and has lectured on sustainability, integrated design, and innovation in engineering. In 2001, he was appointed to the first Bedford Distinguished Chair of Architecture and Engineering, in the architectural and civil engineering departments of Rensselaer Polytechnic Institute in New York.

Interview conducted by Eytan Solomon.

Do you consider yourself a “sustainable” / “green” engineer?
I don’t really think of Buro Happold as a “green” engineering firm. Many people think of us this way because we are a multi-disciplinary company and that allows us to think broader typically than a single discipline focused engineer. Although we’re not reluctant to assume that role, in fact we are passionate about it. It’s sort of funny from a structural perspective, there’s actually a basic paradox with structural engineering and green design. To be “sustainable” in some way you want more material not less, to allow flexibility to systems for future use and to ensure that they are reused in the next building cycle. The basic question is, should it be more efficient or more robust? One of my favorite examples is how downtown [Manhattan] has been adapting and changing its existing building stock. These buildings can be re-used. So one strong view is that sustainability in structures is future adaptability. But then think about the typical new residential concrete flat plate structure built in Manhattan. While a very efficient use of material, can these buildings be re-used for something else? Is their inflexibility inherently unsustainable?

Part of being sensible and sensitive to green design is simply believing a bit. Act responsibly and make sure other members of your design and construction team are acting responsibly as well. In some ways, it’s hard to think of good structural engineering as not being “green” structural engineering.

Structural engineers do need to be more flexible to the requirements of the mechanical or environmental engineer, and they need to be more adaptable than usual. As structural engineers, we are normally involved early in the design process and have an opportunity to help broaden the design discussion. Structural engineers often lead, but with a specific, given systems, without a broad view of things. They need to understand that the mechanical engineering is a greater portion of the building budget, both for initial and running cost.

Structural engineers can also assist in pushing the sustainability agenda by being involved more in the planning process and pushing new materials and approaches. There’s always been a lot of research in lightweight structures for instance, and actually that’s where I came from, that was my first few years of experience at Buro Happold. In this role, structural engineers can have a great iconic impact. For example the Millenium Dome project we designed in London. The weight of the building elements is absolutely minimal and the footprint is over 1million square feet with a weight of structure around 1 to 2 psf, as opposed to 30 – 40 psf for a typical roof structure. Exploring these extreme uses of materials and pushing systems is certainly an area where the structural engineer can help out in developing new approaches, ultimately ones that are more energy efficient.

Is it only on such extreme projects that the structural engineer can be so effective?
No. Experimentation has to happen all the time. But the climate does have to be right for taking the leap. You know, we’re all afraid of making mistakes. The Millenium Dome came out of looking at very simple rental tents in the UK. These are made out of traditional fabrics with flat panels. So we did a couple of small scale structures, and worked our way up. Same thing with cardboard. We’ve done work with Shigeru Ban, the architect who is using carboard in a range of different structures. Cardboard is fun, interesting, completely recyclable, available all over the world.

Do these ideas come out of the blue?
It doesn’t come out of the blue. We are lucky at Buro Happold to have a nice budget for research every year. But we respond to a specific client’s problems. Sustainability is still a new phenomenon in the US. It’s a very youthful field. It’s the young crowd that’s actually technical about it. You know, there’s the established “solar”crowd from the 70's followed by a lull in the 80’s and now it’s popped back up again. I sincerely hope it’s not a fad and I don’t think it is. But there are serious questions to be asked. And it’s not just about LEED. We try to find strong economical reasons behind our sustainable approaches in the office as we believe that you need to go beyond the moral arguments. You’ve got to get to eoncomics at some point. I like to compare the idea of sustainability for two typical building sectors – office and residential. Design of offices and the work environment has great resonance with sustainability as these buildings are dominated by the idea of productivity. Over the life span of the building, human capital is by far the most important thing compared to any other expense like maintenance and energy. So you have to optimize. Build smarter. Use natural light. Create social spaces where people enjoy working. Make sure you’re not breathing in fibrous fire protection and other nasty VOCs. Sometimes it’s so simple, so clear. The economic gains can be significant and smart business owners are certainly catching on. The second track that we think of is “residential,” which is more individualistic. It’s hard to really grasp the problem of global warming on an individual basis, so we tend to think of focused issues: asthma, indoor environmental quality. Creating a better standard of living. There have been some breakthrough projects recently in New York City on this basis. They’ve tapped into the idea of well-being. And people will ultimately pay more for their health and the health of their children. Tackling these ideas is part of developing the technology to implement them and the sustainability field is very technical, which is cool for us as engineers. The “Technical” aspects of sustainability can intimidate architects, owners, and other people. It’s an opportunity for the engineer to show up with solutions and deliver results.

What can the structural engineer do on the project besides writing a “green” spec?
Push for a robust system, which means longer lifespan and greater adaptability. Guide the architect so that structural systems are in tune with the mechanical. Less weight has issues one way or another but always push for better materials. Really, the structural engineer has as much influence outside of our “scope” as within it. Everyone looks to us for answers. So we have to rationalize, our judgment has to be rigorous and sound because we don’t have the performance flexibility of mechanical engineers. Our structure either works or it doesn’t.

What are some of your favorite projects to tout as “sustainable”?
I liked the Grid Shells we have done for many years out of very thin wooden lattices. Form driven, easy to erect, very efficient. They are interesting architecturally, constructed of completely renewable materials, and super light-weight. You really hit the “trifecta” in using those systems. In general I have an interest in light-weight structures. Unfortunately they’ve sort of gone into remission, especially in the United States. Nowadays “light-weight” is described as “complex.” It’s dominated by geometry such as the Frank Gehry-esque structures, which are wild, definitely not low weight or mass. Buckminster Fuller would be rolling over in his grave if he knew how heavy those buildings are!. I think it’s very ironic that light-weight systems have fallen out of favor but there are still a small group of engineers pushing the boundaries here, and I would not be surprised to see a revival linked to ideas around sustainability and energy efficiency.

Where do you see the trends of sustainable design going in the world and in the United States? Energy policy is very important. It’s slowly dawning on the public that 40 to 50% of energy needs go into buildings. Everyone thinks about oil and the Middle East, but there remain great problems to solve in creating more energy efficient buildings. Again, productivity and health are big issues. The next generation of buildings will incorporate those ideas, and if they don’t, they’ll be class B buildings. And it’s not just buildings. We’re doing a public park in California and we are relating the opportunity of improved health conditions to the community. We are hopeful that the trend of more sophisticated thinking of sustainability will continue and to challenge the engineering profession to respond. Even now, it’s hard to find someone, a developer, a client, who is actually opposed to it.

Does working in New York City give you a special perspective?
In working for an international company I have spent a number of years working in Europe and that has given me some perspective on the cultural differences between European and U.S. engineering. In particular, the way that engineers approach sustainability on both side of the Atlantic is very different. We sometimes use the characters from the Wizard of Oz to explain this: The U.S. engineer is like the Tin Man, he has no heart. And the European engineer is like the Straw Man, he has no brain. In the U.S. we are heavily dominated by analysis, numbers, ratios, computations. People try desperately to quantify and find proof in the numbers. On the other hand, European engineers often approach problems with a more fundamental belief in the story, and a willingness to follow through in pursuing the design. So the engineers don’t always have to “prove” ideas as literally.

What experiences or influences led you towards sustainable design?
Working with my partners on the mechanical engineering side of building design. In particular, Tony McLaughlin who worked with us very closely in our NY office for several years. He’s now back in the UK, but we still feel his influence in our office here. He demonstrated so clearly to many architects that engineers can really influence the design direction of a project. The thickness, the massing of a building. Natural ventilation, whether it’s possible or not. I didn’t do much multi-disciplinary design in the first few years of my career, but with Tony’s help, I have since been heavily involved in developing more integrated designs for our clients. Also the architects we work with continually push and challenge us. In particular I would mention Stephan Behnisch as being a strong influence on sustainability. He has really pushed us hard to think and rethink what we do.

What can structural engineers do to promote their standing in the field of sustainable design?
Structural engineers need to understand the drivers behind decisions that architects and mechanical engineers are making when it comes to sustainable design. I see our role as one of enabler – helping to conceptualize forms and systems that are tuned to better building performance. It is important that structural engineers are not myopic and solely focused on designing the “easiest” structural approach. Thinking broadly promotes your standing and the client gets a better product.