Interview: Tristram Carfrae, Arup, on smarter construction and holistic design
As the world’s population increasingly flocks towards urban centres, smarter construction methods and more efficient cities are essential. E&T caught up with Tristram Carfrae, deputy chairman of Arup, to find out about the importance of a holistic view of the built environment.
With such landmark structures as the 2008 Beijing Olympics ‘Water Cube’, the Helix Bridge in Singapore and the City of Manchester Stadium to his name, alongside collaborations with top architects and designers such as Renzo Piano, Richard Rogers, Phillip Cox and Thomas Heatherwick, Tristram Carfrae has established himself as one of the world’s leading structural engineers.
Earlier this year, he was presented with the prestigious Gold Medal award by the Institution of Structural Engineers in recognition of his exceptional contribution to the science and profession of structural engineering. With the increasing technological complexity of modern cities, Carfrae says it is vital to take a multi-disciplinary approach to design.
For the full audio of the interview, click on the SoundCloud link below:
What have been the personal highlights of your career so far?
I’m lucky. I’ve had a long career, worked on many fantastic buildings with lots of great architects in various different countries. The highlight would be the National Aquatics Centre for the Beijing Olympics, also known as the Water Cube, where we made a steel frame like nothing else that’s highly seismically resistant – good for earthquakes – and clad in plastic bubbles that trap all the Sun’s energy and heat the swimming pools.
Who has been your favourite architect to work with?
The architect I have worked most closely with over the greatest period of time would be Philip Cox in Sydney. It’s always a joy working with Philip and we designed some great things together. And we trust each other, so we could start our design conversations literally by talking – ‘What are we both trying to achieve on this project?’ – and get a common objective agreed before we start designing.
What is the relationship like between an architect and a structural engineer?
Some architects are the sole author of a work of art and all they want their engineers to do is make it work. Our job is the second phase of the project if you like: phase one designs it, phase two engineers it. The most enjoyable collaborations I have experienced are like those with Philip Cox where we jointly designed the project for our mutual ambitions.
In that case I will, as an engineer, put forward ideas that the architect may not have thought of and vice versa. It’s an equal dialogue. And that works best on projects where the structure is part of the architecture. I’ve done a lot of stadium design, footbridges, things where the structure is obvious.
As a structural engineer can you sometimes suggest things that the architect would never have dreamed possible?
Absolutely, that happens a lot of the time and that’s where the great delight comes from. A footbridge we did in Singapore, the Helix Bridge, we decided after looking at trusses and other kinds of arrangements that it was actually the spiral elements that were the most interesting and then the challenge was can you actually make spiral elements into a structure? That’s my job.
What is the creative element in being a structural engineer?
I could argue that the whole of being a structural engineer is creative. But it’s coming up with new configurations of structure that work efficiently and effectively and are delightful in a particular context.
The basics of structure – of columns, of beams, of frames and rooms – don’t change. Even the more esoteric bits of structure like arches and cables and even tensegrity structures all exist. It’s how you put them to use in any particular context to get the best possible project.
What have been the major advances in structural engineering in recent decades?
On reflection, nothing has changed actually in the last 35 years and that happens to coincide with when I started my career as a professional engineer. That was when we started using computers to analyse structures across all structural projects. Before that they were very specialised implements to be used on special occasions, but about the beginning of the ’80s it started to be a commonplace tool.
The materials we use today – steel, concrete, timber, glass – really haven’t changed. What has changed is what we do with those computers – our fluency with them, how we use them now to explore ideas before we begin rather than just analyse ideas that we’ve already had.
Are there new materials that are making new things possible or do you still rely on the basics?
It’s largely still the basics although we’re getting better and better at them. There is some fibre reinforcement and things that are relatively new, there are better cement products that are relatively new, we are going to use more timber because it’s the right thing to do environmentally and it’s easy to manufacture.
But there’s an intersection between materials science, economics and the future where we can fully define a building before we build it and therefore we can manufacture it and assemble it on site rather than make it fit as we go along. You can now use the technique that the aircraft and car industry have been using for the last 30 years in the building world.
What do you see as structural engineer role in a sustainable future?
One is reducing the use of material and also making sure it’s used for longer – put less in and get more out of it. The other thing you can do is reduce the embodied energy in the material you are using, because one is just resource consumption and the other one is CO2 emissions associated with that resource consumption.
The third, which is as important if not more important, is make your buildings more enjoyable. For me, sustainability is not just about minimising the cost of everything or the impact of everything, it’s also about increasing the benefit you get from the thing.
Arup is a full-spectrum engineering company. What have you learned working for a company like this?
In the last 15 years, probably I’ve increasingly been responsible for the whole of the engineering of a project, even sometimes the whole of the architecture and engineering of a project, and that makes you think much more widely about what you’re trying to achieve over all.
Nine times out of ten you’re trying to improve the built environment for its inhabitants and in that there is a structural engineering component, but much more important is the whole project and how you integrate what a fire engineer can do, what a lighting designer can do, what a mechanical engineer can do with a structural engineer and architect and try and produce the best building.
That is a totally different challenge to just the best structural engineering – and indeed sometimes it won’t encompass the best structural engineering, because that might get in the way of the best mechanical engineering. So you’ve got a balance for every project: ‘Actually, what’s the best outcome as a whole?’. And the fantastic thing is that Arup, because we’ve got engineers of all these different types, we can have those conversations.
Is that holistic view going to become more important as the world’s population becomes increasingly urban?
Absolutely. Buildings are going to get more complex in the way that they operate and all the decisions have to be taken in the context of everything that’s involved. If you are talking just about energy, the design of a façade, the design of the air conditioning, the design of the controls, and the design of how the building reacts to its inhabitants are all totally interlinked.
What are the big challenges for structural engineering in the coming decades?
I think the big challenge for structural engineers is to help – we can’t drive – but to help the construction industry change from in situ poor, sloppy stuff on site that fits roughly what a building should be, to a manufacturing industry where it’s fully specified in advance so that things can be made accurately wherever they happen to be made – it may be in China or wherever the factories are – and assembled into a functional object on site.