Shells for the senses: the multidisciplinary success of “Stage by the Sea”

When we speak of “aesthetics”, the first sense that comes to mind is sight – when appreciating the “aesthetics” of a structure, we often refer a structure’s beauty. But a secondary definition in Merriam-Webster reminds us that aesthetics can also be defined as “appreciative of what is pleasurable of the senses.”

In Professor Adriaenssens’s words, “a formal analysis, deprived of tactile, auditory and olfactory experiences, seems only to capture to a certain extent the esthetic intent of curved surfaces.” How might structures embody acoustics and the auditory senses? Today we examine Stage by the Sea, a small concert stage in Littlehampton, England that does just that.

Image courtesy of Flanagan Lawrence Architects.

Context-driven design

The design brief first set out by Littlehampton was for a stage and a shelter to occupy its beach and “reinvigorate the town’s gentility of the early 20th century.” The project, being publicly funded, had an extremely tight budget of £100,000.

Beach view from the shelter shell of Stage by the Sea. Image courtesy of Flanagan Lawrence Architects.

There were, of course, additional implied constraints due to the setting of the project. Situated on the beach, the structure had to be durable enough to withstand a harsh marine environment. The public structure also needed to be able to withstand vandalism such as arson or graffiti. Above all, the performance stage of course needed to function well, so acoustic requirements would serve as a particularly major driver in this project.

“[We brought the] notion of a traditional bandstand forward to the 21st century, where social media has democratised the production and distribution of music. No longer the preserve of elite musicians, music is now being made by anyone, and played anywhere. The Stage by the Sea is a response to this context, bringing back an old ideal, an architecture that can represent ‘sound’ and the people [who] made it.” – Flanagan Lawrence Architects and Expedition Engineering

Littlehampton’s Nautical Training Corps Brass Band playing at Stage by the Sea’s performance shell on opening day event, May 2014. Image courtesy of Flanagan Lawrence Architects.

It became clear that effective coordination of the various goals – acoustics, architectural qualities, and structure – would be the key to getting the most value and benefit from a stringent budget. Read on to see how this design team achieved these goals within budget, making such a compelling structure that eventually earned them the 2015 Award for Small Projects from the Institution of Structural Engineers.

The collaborative design process

The successful design team consisted of three firms that excelled in their respective roles: Flanagan Lawrence Architects in acoustic architecture, Expedition Engineering in unusual structural engineering, and Arup Acoustics in technical acoustic consulting. However, even three experts would not have been able to design such a successful project without effective collaboration.

“None of the design disciplines had to make major compromises; it was about working together to achieve the best possible overall outcome.” Pete Winslow, Expedition Engineering

To be more precise about the key to the team’s successful collaboration across disciplines, a single Rhino geometry model was passed between architect and engineer “over twenty times for rapid design iteration and analysis.” Since acoustics were a key driver, the team did not necessarily seek a structure that was shaped to optimally carry dead load.

Iterative structural engineering analysis (in Oasys GSA) and optimization of the shell geometries. Image courtesy of Expedition Engineering.

We were lucky to speak to Expedition Engineering associate Pete Winslow about the process of working on the project in a multi-disciplinary context. “We [structural engineers] did not prescribe a funicular, or pure compression, structural form,” Winslow says. “Rather, we developed and communicated an understanding of how much bending could be accommodated – for example, in the peak, and close to springing points – without needing to unduly thicken the shell or disproportionately increase the amount of rebar.” But likewise, “acousticians did not prescribe every internal dimension. Rather, they put forward key ratios, such as height/width, or shell peak cantilever distance / depth of stage.

Concept sketches and acoustic diagram. Image courtesy of Expedition Engineering and Flanagan Lawrence Architects.

“One of the most interesting things about the project is that, in my view, none of the design disciplines had to make major compromises,” Winslow says. “Nobody was saying, ‘every aspect of the form must be like this’ to the detriment of other disciplines. It was about communicating and understanding the main drivers for from each discipline.”

Sustainability in the long term

A final driver guiding the design decisions and compromises was the structure’s durability. “Whilst conventional thinking says that reducing the absolute value of embodied carbon in a structure is desirable, once this figure is spread over the expected design life / life to first major maintenance, the situation can significantly change. Therefore, we decided to explore all practical measures for increasing durability and life, and then within those constraints looked to minimise quantities of material and embodied carbon.”

As an example of how this approach affected the design process, Expedition Engineering pointed out that “in terms of ultimate load capacity, a thinner shell could have been possible. However, the overarching requirement for durability translated to limiting crack widths to 0.15mm.” The team thus optimized thickness around the resulting constraint – stresses within the shell.


An unconventional construction technique was used for this project: shotcrete. Unlike traditional concrete construction, shotcrete applies concrete by spraying it at high velocity onto a surface. It is often reinforced by steel bars or a mesh.

Spray concrete application of Stage by the Sea. Image courtesy of Pete Winslow, Expedition Engineering.

“When [conversations] went towards construction, the base method proposed was to build up a formwork and cast concrete in situ, since many contractors can do this,” says Winslow. “Conversations with Shotcrete Ltd, who are experts in tunneling, highlighted that they could very economically do it as a spray-concrete shell, which required no formwork required and achieved a high quality finish.”

“The judges greatly admired the way in which value for money has been delivered to great effect through the structural engineers’ creative thinking and confidence in eschewing complex construction techniques – instead putting faith in simplicity and skilled craftsmanship.” – IStructE award judge comments

Winslow admits that “getting the right shell geometry built on site to tight tolerances on a very limited budget” posed a challenge in construction. Since the project was so small, the team knew it would be uneconomical to use “clever (but expensive) high-tech things like CNC’d polystyrene, laser scanning, or computer simulated or bent rebar.” They improvised: “the thoughtful use of BIM and integrated common models allowed key information to be communicated to the small construction team, who could quickly and simply set out the doubly curved form on site using a conventional scaffold on a 1m x 1m grid. A modest survey and cross-check against the BIM model ensured the geometry was correct, prior to curving and fixing the bi-directional rebars over the top of this scaffold framework, therein defining the complete shell shape.”


BIM model setting out used for construction. Image courtesy of Flanagan Lawrence Architects.
Shell reinforcement with temporary scaffolding used for construction. Image courtesy of Flanagan Lawrence Architects.

The final result

Today you can find Stage by the Sea, two thin concrete shells oriented back-to-back, on the East Beach of Littlehampton. The larger shell faces inland and serves as the performance stage; the smaller shell sits along the East Beach promenade and faces the sea to provide shelter for passersby and buskers.


Site landscaping of Stage by the Sea. Image courtesy of Flanagan Lawrence Architects.

The impressive thinness of the shells demonstrate that formal elegance were not compromised for acoustic function: “the shells are 100mm thick reinforced concrete, increasing to 150 mm at the more highly stressed springing points, and bi-directional rebar. At the crisp leading edge, a stiffening strip is introduced with minimal increase in overall thickness; instead, additional rebar is introduced with smaller cover.”

Reinforcement details and stage cross-section. Image courtesy of Expedition Engineering.

As for acoustic function, the performance stage delivered – the violinist playing on the windy opening day could still be heard perfectly well from 50m away.

“The wave-like form follows the acoustic function beautifully.” – IStructE award judge comments

Acoustic form refinement. Image courtesy of Flanagan Lawrence Architects.

The shells are also well-loved by the community. “I particularly love the public booking system open to anyone,” Winslow says. “It very much makes it an accessible community facility.”

Sea-front shelter for local residents. Image courtesy of Flanagan Lawrence Architects.

Winslow shares a final touching story demonstrating Stage by the Sea’s place in the hearts of the people: “Over the weekend, a vandal had painted graffiti on one of the shells. It was reported to the council, but almost immediately a group of locals got some paint and painted over the graffiti to restore the shell to pristine condition!”

Visit the team: Expedition Engineering | Flanagan Lawrence Architects | Arup Acoustics

See more at Expedition Engineering’s project page.

Expedition Engineering’s close collaborations with Flanagan Lawrence in acoustic architecture continue. Check out their Soundforms project!

Any quotes not attributed to Mr. Winslow are taken from Expedition Engineering’s pamphlet about the project, which he provided for us. We thank Mr. Winslow for all of his help in making this post possible!

Author: Demi Fang ’17

What I am Thinking: Architectural Fantasies with Mister Mourão

While at the 2016 International Conference on Structures and Architecture, we had the opportunity to meet Mister Mourão, a highly creative mind who describes himself as “an architect turned illustrator with a tendency for obsessive drawing.” In this interview, he shares his beginnings in drawing, his productive workflow, and his inspiration (or lack thereof).


When, what, how and why did you start drawing?

Drawing was always one of my favourite things to do. There’s something in the effort, dedication and loneliness of the work that resonates with me.

One of my first memories is being on my parents’ living room floor drawing, so I guess I started pretty early… And for some unknown reason I was obsessed with horses. That’s basically what I drew from 4 until 18 years old. Horses!


What was your formal training and how does it relate to your work now?

I studied and worked as an architect so my lexicon is deeply rooted in the city, structures and urban environments.

Basically, I learned how to design and build through architecture, and now I can distort, exaggerate and repeat all those architectural elements that make up a building or a city and rearrange them in my drawings.


What is your process?  

First I have to confess something about myself. I (obviously) love to draw but I’m quite lazy and restless, and it’s very hard for me to focus.

In order to deal with these shortcomings, I had to design a strategy in order to do the work that is important to me.

I’ve set up a few simple and easy to follow rules to keep me where I want to be. Drawing.

This is my humble attempt to design my workflow.

  1. Simplicity
    I (mostly) use a black pen and paper.
    This way I don’t wander off looking the “right” tool or color.
    It’s just me, the pen and a sheet of paper. With nothing to decide, I just draw. It can’t get simpler that this!


  1. Silence
    As we all know too well, we live in the age of distractions… so I put my phone on airplane mode while I’m working. It’s a cheeky trick but it works!
    No calls, no pings, bing or buzz! I have enough trouble trying to focus by myself without all the notifications luring me to that rabbit hole!
    After doing this for a while, it was fun to realize that there aren’t many things that can’t wait for 4-5 hours. And no, you don’t need to reply to that Facebook comment within 2 minutes!
    Oddly enough, after creating this silence, I fill it with some nice music or podcasts.


  1. Routine
    It’s easier to get the work done if I have a fixed daily schedule, this way my brain know when it’s time to draw.
    So everyday I divide my time in big blocks and try to do the important work from 10am until 3pm. I’ll defend these 5 hours of uninterrupted work against everything! Because I know that the first hours are usually worthless and I need to keep working through it non-stop until the final hours when things starts to happen.
    To mark the end of a work day, I post a photo of the day’s progress on social media.
    This gives me the feeling that I’m accountable to be there the next day and keep going.
    How’s that for a productive use of social media?!


  1. Mistakes
    Probably the hardest thing to figure out for me was to learn to deal with mistakes.
    Being a perfectionist is a curse in disguise because it’s very easy to get lost in a endless loop of do-undo and never get to the end of a piece.
    That’s why I decide to work on a medium where I can’t erase or undo. With pen and paper, there’s no backdoor.
    Sure… I scream and kick the wall when I make a mistake but at the end I just have to carry on and finish the drawing.
    Now I cringe a bit when I look at the mistakes in my drawings, but I can see them as an important part of the process.



Where do you get your inspiration?

There’s a great quote of Chuck Close that really rings with me. “Inspiration is for amateurs, the rest of us just show up and get to work.”

Surely my background, the places I visit or the people I meet are important and fuel me subconsciously but I don’t really believe in getting inspiration from some other place besides the work itself. The challenges and decisions inherent to working on a piece are inspiring enough.

How do spectators respond to your drawings?

Sometimes they believe to recognise a specific part piece of the drawing from a city or building that they know.

I have a friend that swears that I drew her doorway (which I didn’t) in this drawing that I’ve loosely based in the city of Oporto, Portugal.


What is your greatest accomplishment so far and why?

I guess to be able to make a nice living from drawing is something that makes me really proud (and a bit surprised).

To make something so personal that gives me so much pleasure and getting paid for it feels like a magic trick.

Also the opportunity to work with AppleThe New Yorker & to create a 12 meters mural in my alma mater are surely among my professional highlights.

Which question would you like to be asked (and never get asked) and what would be the answer?

Do you think anyone can draw? Yes, if you really wanted it. Because grit trumps talent any day. So if you want and love to draw, you CAN draw.

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We loved meeting Mister Mourão at ICSA 2016! Here we pose with his work-in-progress: a mural at the School of Architecture of University of Minho, his alma mater. He completed the mural during the conference in 10 days! Left to right: Sigrid Adriaenssens (Form Finding Lab), Giulia Tomasello (Roma Tre University), Mister Mourão, Stefano Gabriele (Roma Tre University), Lukas Ingold (ETH Zurich)

Visit Mister Mourão: | |

Author: Sigrid Adriaenssens

Our Summer Rammed Earth Experiment 3/3:

While we’ve completed construction on the rammed earth spiral, the project has really only just begun. Moving forward, our team is looking to properly introduce rammed earth into the Princeton community and to further research efforts by installing a sensor system to study rammed earth erosion and by building a solar-paneled roof over the spiral wall.

Community Engagement: Redefining Structures, Sustainability, and Service

Rammed earth is a uniquely sustainable, beautiful building material – and completely foreign to most people. With this project, we saw the opportunity to do more than research and focus on the idea that structures are built to interact with people. We wanted to create something that could broaden our community’s views on structures, sustainability, and service.

Working with the PACE Center for Civic Engagement, we’ve been able to expose Princeton students to rammed earth through volunteer events and service discussions. A student volunteer described how “the project had made us work together and become a single unit,” unknowingly hitting the mark on an ancient quality of earthen construction. Especially in developing areas where heavy machinery cannot be employed, earthen construction is known as a community building event. At a lunch event hosted by the PACE Center, our project incited a discussion between students from various departments about research as a form of service. We hope to hold similar events during the school year, as well as transform the Forbes Garden into a more usable space for all, where students can have class, a movie night, or just a place to relax and study.

We’ve also enjoyed holding workshops with local schools and summer camps, hoping to inspire students in civil engineering and STEM. Visiting students learn all about rammed earth construction and get to make their own rammed earth samples. Joint workshops with the Forbes Garden managers, sponsored by the Office of Sustainability, expose students to two very different but basic means of sustainability in their every day lives – sustainable food and shelter. So far, we’ve had collaborations with the Princeton YMCA, the Laurel School, and Princeton Nursery, and look forward to hosting more workshops in the near future.

Ongoing Research: Erosion Protection and Environmental Sensing

One of the primary reasons rammed earth is not a prevalent construction technique in areas with varied, seasonal climates such as New Jersey is a lack of understanding of structural erosion in winter temperatures and driving rain. Several studies have predicted that the actual erosion of rammed earth walls due to wind and rain in seasonal climates is negligible in comparison to the lifetime of the structures. Our research aims to compare the erosion of four rammed earth test walls, both with and without alterations to prevent erosion.

To quantify erosion, we will use an image-based modelling software to create 3D models of the wall and compare changes throughout time. We are also installing an array of soil moisture, temperature, humidity and radiation sensors to see how these environmental factors correlate to erosion on the different walls. As for the walls themselves, the different protection measures include chemical solutions – lime and silicone, and a natural solution – a native ivy. Our results can eventually add to the formation of rammed earth building codes and lead to the wider presence of rammed earth construction in seasonal climates.

Author: Amber Lin ’19

read Part 1 | read Part 2

“Postcards From …” Series: Summer 2016

Throughout the summer, friends of the Form Finding Lab have been sending postcards from the places they have visited. The postcards are also featured on our Facebook page. For this special summer post, we’ve compiled the postcards for all to enjoy!

For the next 2 weeks we are on vacation. Stay tuned for more of our exciting posts in September!

May 2016
May 2016
May 2016
June 2016
June 2016
July 2016
July 2016
July 2016
July 2016
July 2016
July 2016
July 2016
July 2016
July 2016
August 2016
August 2016

August 2016

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August 2016

Author: Victor Charpentier


In the spirit of the Olympic Games: the “Carioca Wave” Freeform of Rio de Janeiro


The Carioca Wave was completed in 2013 in Rio de Janeiro, not far from the 2016 Olympic Village site. We first discussed this structure in our interview with Knippers Helbig. In this post we observe architect Nir Sivan‘s design process for designing this elegant structure.

Creating the “Carioca Wave” project in Rio

When Nir Sivan got the opportunity to build a freeform steel/glass canopy roof as a welcoming entrance area to “CasaShopping,” South America’s biggest design center, he was thrilled and knew that whatever he designed, it had to be and behave as a part of the “marvelous city,” as Rio is often nicknamed.

Nir Sivan started working on the master plan in his office in Rome, but the actual shape of the project was only designed when he came to Rio. The inspiration came while he was sitting on one of the many famous beaches with a local cold drink. He remembers drawing in his sketchbook – 5 or 6 simple lines, but they captured it all:
 the calm; the movement; the sound, the “Carioca,” as locals from Rio area are called.

He created a shape of a single yet geometrically complex surface of the double curvature. The surface starts at the upper floor above a blue colored water pool, then rises up curving, growing forward, twisting to the other side, and finally dropping down to a lower floor, splashing into a white colored pool. Around it you will find water, sand, Portuguese paving, and other elements to merges the project with the local language.

Inspired by its context, the project was driven artistically and emotionally, and developed architecturally, adding both value and function to its surroundings.

“Sculpting architecture”

The design approach included sculpture and design methods that were further developed using automotive industry tools and advanced parametric instruments to ensure tight control of the very particular geometry. Nir Sivan developed this unique process involving automotive industry, believing it gave him complete freedom to create while maintaining coherence with concept, structure, and form.

Putting things together

Nir Sivan’s projects often require cutting-edge technologies as well as advanced fabrication and installation techniques. The Carioca Wave gridshell uses over 110 tons of carbon steel (fabricated in Czech republic), including 36mm-thick double-curved tubes, 765 different beams, and almost 300 different laser-cut shaped nodes, creating 503 varied triangles accommodated by glass panels that weigh 45 tons (fabricated in Japan) – all shipped to be installed in Brazil.

The partially-clad Carioca Wave gridshell is temporarily supported during construction.

As he often does in similar projects, Nir Sivan created a design-build group: he teamed up with engineers Knippers Helbig (Germany) as right-hand partners and construction company Seele (Austria HQ) for fabrication and installation. By doing so, he was involved in all aspects and processes of the development, assuring that his design intentions were maintained and that the final results corresponded to his expectations. The client was free from any responsibility of coordinating this international team.

Architecture precedent

The structural frame of the Carioca Wave canopy is a self-supporting gridshell, requiring neither columns nor lateral supports. Nir Sivan sought to combine this self-supporting system with wide cantilevers to push technology to its limits. As Nir Sivan was informed during its design, the Carioca Wave is the first freeform architecture in South American history.

Nir Sivan believes that people appreciate design and recognize the “added value” of implementing new techniques and technologies. He looks forward to sculpting more architecture worldwide.

Close-up of the gridshell support, lit at night

Image Courtesy Nir Sivan Architects

You can read more about Knippers Helbig Advanced Engineering in our previous post

What I am thinking: from Stuttgart to Rio 2016 SBP’s stadium designer Knut Stockhusen


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Rio de Janeiro, with Stadium Maracanã in the distance. © Marcus Bredt.

The world has tuned in to the Olympic Games in Rio de Janeiro to witness the highest caliber of athletics. However, unbeknownst to most spectators, this is also an occasion to see first-rate structural engineering: A lot of the action will be taking place against a backdrop of stadia and venues made possible by the work of schlaich bergermann partner (sbp).

Engineer Knut Stockhusen is a partner and managing director at sbp, and was paramount in establishing sbp’s presence in Brazil. In April, he came to visit Princeton to give a lecture and workshop on deployable roof structures, and I was lucky enough to sit down with him for a conversation.

Before talking about Brazil, I first wanted to hear more about schlaich bergermann partner.

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Rio de Janeiro Olympic Live Site (2016).© Dhani Borges

Olek Niewiarowski: You’re always traveling and working around the world, but you’re based in Stuttgart, Germany. How is that like?

Knut Stockhusen: Our HQ is in Stuttgart, that’s where a lot of our activities are coordinated. But we have five other offices: Berlin, where Mike Schlaich is professor, New York, Sao Paulo, Shanghai, and we opened an office in Paris just this year. We noticed over the last few years that while it’s good to have one “base camp”, we still need several locations where we can work and live. We can’t travel all the time, and it is paramount to adjust to the local culture and the way of doing things.

What is special about Stuttgart?

There are many things special about Stuttgart. Stuttgart is the place where a lot of technology and engineering got established. In our field, Fritz Leonhardt started his incredible career in Stuttgart. He had a very progressive approach and revolutionized the whole engineering world with principles that are still commonly used all around the world. For example, look at the Stuttgart Television Tower: It was the first of its kind in the world and it got “exported” everywhere. This environment was a very powerful base for new stars to rise, such as Jörg Schlaich. He started to develop new approaches to cable structure design for bridges and for other tensile structures. With the solution for the Olympic stadium in Munich, he not only developed, but also revolutionized that field. The influence of Jörg Schlaich on engineers in Stuttgart is quite visible. Of course, everyone develops their own approach, but it is very interesting to have several important players in such proximity. Sometimes it leads to competition, but in most cases it is just nice to be enveloped by such excellence.

It sounds like the “DNA” of the firm crystallized early with all these lightweight structures. On a day to day basis, how do you keep the SBP style alive?

In a way, it’s a certain engineering philosophy that we pursue. Its seeds came from Jörg Schlaich and Rudolf Bergermann, in the constant pursuit of an incredible variety of international projects and technologies, where the limits of feasibility were pushed constantly.

Those values were successfully inherited, enhanced and carried into a new era by the next generation of partners and the whole team. The will to explore the unexplored, to venture into new fields, to never hesitate, and to keep on developing, evolving and sometimes revolutionizing in a structural sense. That is something we live by on a day to day basis.

Can you give an example of how you live by this philosophy?

We are active in most of the fields of structural engineering. If you look at one of these, the field of stadium and large-span roof design, we have designed something like 50 stadiums around the world. Now if you compare the solutions, you will recognize that none looks like the other. Of course, every time we start a new project, we base our approach on what we learned before, but we yearn to develop something new. We try to find solutions that suit to the architectural layout, the environment of the city, and to the capabilities of the region. We try to form new creative teams, develop something that was never done before.

So maybe we can talk more about stadiums: What was your most challenging stadium project?

In terms of the combination of environment, cultural surroundings, and the technical capabilities of the region, the projects that we did in New Delhi were probably the most demanding. We designed stadiums for the 2010 Commonwealth Games and started our operations there in 2006. For the main stadium, the job was to develop a new spectator approach and roof structure. Since the existing tiers were in a state of conservation that was not so, let’s say, promising, we decided to do an independently-supported roof. Due to the setup there and the decisions taken by the authorities, that project really demanded a lot from our team, from myself, and the office. For example, they allowed the contractors to fabricate on site. So they first started to build fabrication plants on site, and the steel suppliers would just drop off the steel plates on site and the contractor would start to weld everything there.

We had to involve our fabrication experts to, for example, guide the contractor to build covered work areas to get out of the sunlight, because you have extreme heat and your steel distorts and all your lengths get messed up. It turned out well at the end of the day, but it was really challenging.


JNS Jawaharlal Nehrun Stadium (Delhi, India, 2010). The stadium features a classic SBP ring-cable system based on a spoke wheel. © Knut Stockhusen.

It sounds like you must be really aware of how things get done on the ground before you can even start designing?

Our approach is to design with excellence, perfection and uniqueness, but always considering the fact that someone is going to build what we’re designing.

We analyze the possible setup of the contractors, we consider their capabilities and who will actually do the work at the end of the day. We try to be involved in these projects from the first sketch to completion, in order to guide the client, who maybe has never done this before.  To achieve the best setup for fabrication and construction, we have experts in all fabrication issues who survey and guide fabrication. And in this particular case in India, we had to establish a full-time supervision team on site, which was not planned for in the beginning. They actually taught unskilled workers on site how to weld and then test the welds, in order to guarantee that the whole structure is capable of 50-year lifetime.

So when you talk about supervision, how does a contractor in India respond to that? Is that something they are used to, or was it a new thing for them?

The detailed involvement of a structural designer was an extremely new experience for them. And it is actually new at many projects. Our philosophy of not “letting go” of a project once the design is finished may create a certain friction in the beginning. However, in all the cases that we’ve been involved, it turned out to be a truly successful collaboration in which the site teams appreciated our input. You need time to get used to each other, and that demands a lot from both sides.

We are engineers who roam the world looking for beautiful projects. We cannot expect and we don’t want to expect that people get used to our culture. Maybe to our culture of building, the culture of construction, and certain safety standards, yes, but it is our duty to get used to the circumstances of a particular region and to rules of engagement.

This can be very exciting and at the same time very demanding, but it’s also rewarding because you get to know the culture, you get to know the people. Everyone in the company who gets to travel to sites establishes strong friendships that add to the success of schlaich bergermann partner.

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Stadium Maracanã (Rio de Janeiro, Brazil, 2013) © Marcus Bredt.

SBP’s Sao Paulo office opened before the 2014 World Cup. What was your role in that again?

We opened the office in 2007 and I almost moved there because I traveled every third week or so. Together with our Brazilian director Miriam Sayeg, who is crucial to the success of the establishment, I manage the South American activities. You need someone who is engaged in the local community and environment, especially in a country like Brazil, someone from Brazil who knows their way around in terms of communication and culture and networking.

Do you have a favorite stadium in Brazil? Is there one we should look out for during the Games?

Normally, the Olympics are held in one city – it’s called “Rio 2016” for a reason – so it becomes its own brand. The interesting thing about Rio 2016 is that some events will take place in other cities in some of the stadiums built for the World Cup, because they are there! For example, the Arena da Amazônia in Manaus will host soccer.

Which stadium do I find most interesting? From an emotional and personal point of view, I would say Maracanã Stadium. It’s the one that you dream of as a stadium designer (and a soccer fan) and it’s a spectacular project in a very spectacular environment.

Stadium Maracanã © Marcus Bredt.

But the Arena da Amazônia is also a very special project for me. It took a great deal of personal effort to engage in the environment and to realize that project in such a special and remote city. I believe the design is really incredible: it’s a very beautiful project – in a wonderful part of our planet.

Arena da Amazônia (Manaus, Brazil, 2014) © Marcus Bredt.

Everyone is worried about the rainforest and that is also very important for us, so it’s also interesting to mention that no tree had to be cut down to build the stadium. But in particular, no one would have taken notice of this region during these mega events if there wasn’t a venue there for certain games. So now, like in the World Cup, billions of people will look at that region and maybe start thinking.

For the people living there it is very important to be part of the whole show. That’s already a good reason for having the Arena da Amazonia in Manaus.

So does that tie into the social responsibility that sbp advertises? It sounds like you can make stadium building a sustainable venture.

Yes, in a way it is part of our philosophy that we try to reflect in the way we design. We design structures that can engage the local capabilities and work force to create jobs. On the other hand, the main motivation to work in the field of lightweight structures and intelligent structural systems is to try to avoid wasting resources. Sustainability is a very big term that everyone is talking about. What is really sustainable?

The material that is not used is the most sustainable material, hence we try to limit the use of natural resources as much as possible. By doing that, the beautiful lightness of our design becomes visible.

Not everyone has to love it, but in our eyes, the lightness and elegance of slenderness motivates us to come back day after day.

We were running out of time, but I still had two very important questions for Knut.

What question do you never get asked, but would like to be asked?

Ah yes, that is the most important question. The question would be, “Are you happy with what you do?” Yes, I’m very happy. We are happy with the work that we do; it’s a very profound work. There is also this sense of evolution and development that is the foundation of our great team. It inspires and keeps people in the office. They see that they can contribute and have a significant impact.

What is your advice to students interested in lightweight structures?

Call me.


Author: Olek Niewiarowski

All images courtesy of Schlaich Bergermann Partner.


A New Design for the Tokyo 2020 Olympic Stadium

Looking ahead, the next Olympic Games will be hosted by Tokyo in 2020. The initial Zaha Hadid design for the Tokyo National Stadium helped secure the city’s bid, but was quickly ditched due to its exorbitant cost.  After two international design competitions, Japan settled on the latticed green clad stadium by the Japanese architect Kengo Kuma.

This new stadium is far more subdued than Zaha Hadid’s and does not evoke the same awe as the National Gymnasium by Tange and Tsuboi Yoyogi.

To reflect upon and honor the structural prowess visualized in the sweeping roof lines of the Yoyogi Stadium, as well as to keep an open mind toward the future, the International Association for Shell and Spatial Structures (IASS) organized a conceptual design competition for a new national stadium in Tokyo, open to young designers under the age of 40.

The competition called for a “21st century spatial structure” on the site of the former National Olympic Stadium by Mitsuo Katayama. The competition jury, consisting of professor emeritus Hiroshi Ohmori (Nagoya University), architect Hiroshi Naito, engineer Knut Stockhusen (sbp), professor Ken’ichi Kawaguchi (University of Tokyo, Chair of the IASS2016), and engineer Bill Baker (SOM), considered the innovativeness of the concept system and the soundness of the structure.

I have the pleasure of presenting three design proposals developed and submitted by our graduate students. They all used form finding techniques in innovative ways to drive the geometries of their stadiums.

The Mountainous Gridshell entry by Mauricio Loyola and Olek Niewiarowski has been selected as one of five finalists by the competition jury, and they have been invited to present their design in September at the IASS Annual Symposium in Tokyo.

NEW LEAF STADIUM by Xiaoran Xu, Lu Lu, and Iwanicholas Cisneros (click to enlarge):


HANA STADIUM by Kaicong Wu, Hongshan Guo, and Isabel Morris (click to enlarge):


MOUNTAINOUS GRIDSHELL by Mauricio Loyola and Olek Niewiarowski (click to enlarge):


Author: Sigrid Adriaenssens


Our Summer Rammed Earth Experiments 2/3: Construction of swirling rammed earth wall

Before the large swirling structure in Forbes garden could be constructed, a set of tests walls were built to master the construction workflow. The tests walls will also be used to test a different set of erosion protection measures, as one of the goals of our research experiment is to assess the erosion resistance of rammed earth in New Jersey. The first test wall was built out of unstabilized earth with no erosion protection implemented for reference. The second wall was also unstabilized, but plants will be grown on top of this wall in the hope that their roots will slow down the erosion process, while their leafs protect the dirt from driving rain. The third test wall was stabilized on the outside with a 10% lime-earth mixture, which was applied only at the outer 3 cm. This technique is a traditional rammed earth construction technique originating in Spain and referred to as “calicascado” which can be freely translated as “lime shell”. The 4th and final test wall was built unstabilized earth once again again, but half of it was coated using a silicone spray, while the other half was coated with a lime wash. All of the test walls were built with a reusable plywood formwork on top of a blue stone slab..

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Scheme of the test walls
Rammed earth test walls. Both left walls are unstabilized, the wall still in the formwork was built using the calicascado technique.

After the successful completion of the test walls, we moved on to the much larger spiraling wall inside Forbes garden. As explained in the previous blogpost, the spiral consists of a lower bench area and a taller wall, separated by an opening. At its lowest point the bench is 40 centimeters high, and at its highest point it is 3 meters tall. Both rest on a blue stone foundation. Again, different erosion-protection measures were implemented. The bottom 15 cm of the entire wall was made out of a 25% lime- earth mixture, and placed on a water impermeable membrane to avoid capillary rise. The outside of the bench and most of the rest of the spiraling wall was stabilized using the calicascado technique after its promising results on the test walls. A great advantage of this technique is that it allows for a minimum volume of soil that needs to be stabilized with lime and thus requires less material transport. To compare the durability of the technique once again a section was left unprotected. Additionally, one section of the wall was entirely lime-stabilized using 6% lime as an extra test.

Lime-stabilized outer layer (“calicastrado”) waiting for infill dirt.

One of the goals of the project was to demonstrate that it is possible to break away from straight rammed earth walls and build elegant curving elements. This required the construction of curving formwork, which was assembled from standard wooden 2″x4″ elements and bendable plywood. To account for the huge outward thrust created by the compaction, horizontal support triangles were built from using the same wood. Additional horizontal pieces were screwed in between the supports to prevent bulging and cracking of the plywood.

(From Left to Right): formwork assembly, manual spreading of the earth, bendable plywood sheets being installed, pneumatic compaction of the soil

The actual ramming of the earth was done by coating the formwork with a 3-4 cm thick layer of lime stabilized earth (mixed on site), which was then filled with local Princeton soil from the Princeton University construction yard. This soiled had been screened through a 1 inch mesh and moisturized to the optimal water content of about 10%. The soil was lifted into the formwork using an excavator, after which it was spread by hand, and then compacted using pneumatic backfill tampers.

 (From Left to Right): Excavator filling the wooden framework with earth, Flattening the earth with tampers, Compressing the earth with pneumatic tampers

Subsequently, the formwork was disassembled and peeled away from the compacted earth. This is a fairly easy process thanks to the thrust exerted by the dirt. The majority of the lumber used for the formwork will be recycled and reused in a next construction project.

View onto the swirling wall

Finally, the top of the wall was covered with a water-resistant membrane and planking of untreated cedar wood.

We would like to thank Shana Weber (Princeton University, Office of Sustainability), Sean Gallagher and Brian Scelza (Princeton University, Facilities)  for their support for our project.

Author: Jacob Essig & Tim Michiels

Project By: Tim Michiels & Sigrid Adriaenssens

Construction team: Tim Michiels (project coordinator), Eric Teitelbaum (coordinator formwork construction), Amber Lin, Jacob Essig, Victor Charpentier, Sigrid Adriaenssens, Olek Niewiarowski, Princeton University Civil Construction: Steve, Paul and Mike.

read part 1 | read part 3

A Delightfully Sweet Pavilion

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Close-up of the puzzle-key connection in the chocolate pavilion. (Image credit Axel Kilian)

On July 21st every year, we celebrate Belgian National Day and think about all the good things Belgium has to offer: Tintin, cycling, soccer, and– from a more gastronomical perspective– waffles and chocolate. This is an ideal time to reflect upon our chocolate design project from 2013.

A pavilion made out of chocolate must be a cocoa lover’s wildest dream. We teamed up with Prof. Axel Kilian (Princeton University) and the Belgian chocolate manufacturer Barry-Callebaut to discover chocolate’s structural properties and let them inform our methodology for finding the shape of such a pavilion.

The R&D branch at Barry-Callebaut developed a cocoa compound of sugar, cocoa powder, milk permeate, and vegetable oil that would be structurally strong enough to support the pavilion’s own weight at room temperature. We tested the compound mixtures and found that the strength-to-weight ratio of chocolate compounds is quite low — about 24 times lower than standard concrete.

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Testing material properties in the lab

After deliciously physical experiments with chocolate pneumatic shell forms, inverted tree networks, saddle forms and hanging fabric models, we settled for a hanging fabric shell model as a form finding approach for the pavilion. With only the self-weight of the chocolate to carry, this catenary form was the most structurally efficient. As long as creep and global buckling were considered in design, it provided a structural system that could span the farthest using the smallest amount of material. Although it was appealing to exploit the rheological properties of the chocolate and explore flows of forces by pouring material onto formwork or dipping material, the practicality of this application method would break down at a large scale with a limited construction time frame. Considerations such as control over material thickness, adherence to support formwork (whether flow over steep formwork or accumulation on a set of strings), the setting speed of chocolate, and assurance of a monolithic form raised large construction challenges.

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Four different physical form-finding approaches explored for chocolate compound material. Left to right: pneumatic shell forms, inverted tree networks, saddle forms, and hanging fabric models. The last model was selected.

We developed a digital parametric model that integrated form finding, shape optimization, planarity mold, and patterning algorithms. The prototype we built consisted of over 70 individual frames of chocolate that puzzled together into an open-air domed pavilion. This real-life chocolate pavilion seemed to come straight out of Willy Wonka’s chocolate factory.

Digital and physical instances of the parametric design to construction workflow
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Experimenting with mold forms, materials, and connections
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Chocolate Plated Grid Shell Pavilion (Image credit Axel Kilian)

This blog post is based on Alex Jordan *13’s research towards a masters thesis. You can find more about our project here.

Author: Sigrid Adriaenssens

Editors: Jacob Essig, Demi Fang ’17

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Our Summer Rammed Earth Experiments 1/3: The Golden Spiral for Forbes Garden


Dirt—as in clay, gravel, sand, silt, soil, loam, mud—is everywhere. The ground we walk on and grow crops in also happens to be one of the most widely used construction material worldwide. Earth does not generate CO2 emissions in its generation, transport, assembly or recycling and this in contrast to more conventional building materials such as concrete and steel. In rammed earth construction a mixture of  clay, silt, sand and gravel is compressed into a formwork to create a solid low-cost load-bearing wall. Despite the renewed architectural interest in contemporary rammed earth construction in (semi-)arid climates of the USA, little is known about its potential in the erosive humid continental climate of New Jersey. Because of the great potential of rammed earth as a local building material, we decided to design and construct a spiral rammed earth structure in Forbes Garden that will be an enduring representation of Princeton’s effort to create a campus containing sustainable and elegant zero carbon architecture.

The Material:  Dirt

The Form Finding Lab’s team established the suitability of Princeton soil for earth construction though an extensive set of laboratory tests. The team, led by PhD candidate Tim Michiels and supported by undergraduate student Amber Lin ’19 and summer intern Jacob Essig, subjected a series of compacted samples with different water contents to compression tests (the rammed earth samples had an average compressive strength of 1.35 MPa). The team also experimented with lime additives  (3%, 5%, 10%, and 25%)  to test the compacted dirt’s resistance to weathering on a series of prototype walls (See image above title).  All these results informed the design of the structure that was designed for Forbes Garden as part of the Campus as Lab Initiative .

Testing of compacted samples with different dirt compositions to establish unconfined compressive strength. The local soil was composed of 19% gravel, 42% sand, 24% silt and 15% clay.

The Site: Princeton Garden Project

The Princeton Garden Project at Forbes College is a student led initiative that supports and advances sustainability and food awareness  on Campus. Following with its mission of sustainability, the rammed earth spiral is a sustainable experiment made with local and abundantly available materials intended to enhance the existing organic garden and transform it into a space for research and learning.

The Garden Project, the ideal collaborator for a rammed earth project (image credit Garden Project at Forbes College)

The Design:  A Site-Specific Golden Spiral

Spirals occur all throughout nature. For example, we see them in the trajectories of sunflower seeds and pine cone kernels in Forbes garden or in the pictures of Karl Blossfelt (1865-1932).  We adopted this familiar shape and designed the Forbes Garden spiral as a golden spiral, a type of logarithmic spiral whose growth factor is the golden ratio. We positioned the spiral with respect to the sun in high summer so that the structure would cast shade. To further enhance the visual aesthetic experience of visitors, we worked to ensure that there was a straight line of sight from the lower part of the swirling wall, which serves as a bench, towards the Gothic Cleveland tower and carillon which dominates the Graduate College landscape. To invite visitors to spend time in the garden and experience the raw and minimal character of the  structure, we designed the lower part of the spiral as seating. The size of the swirling curve was fixed by anticipating the range of comfortable distances from a fire pit, which will be placed in middle of the semicircular slower section. As the bench slopes gently upward from a minimum of 40 cm, it allows comfortable seating tailored to garden-enthusiasts of different heights. The bench is furthermore separated from a wall that reaches a height of 3 m to allow for different seating heights on the lower end, as well as to ensure sufficient clearance for a sense of openness of space at the higher end, where a shading roof is planned. Additionally, the wall’s varying height needed to be adapted to match the slope of the uneven terrain of the garden. These constraints, together with structural stability considerations, informed the development of the 3D shape of the Spiral. Stay tuned for our next post  to find out how we figured out how to build such a complex geometry in dirt!

Spirals in the plants photographed by Karl Blossfelt
Site plan showing sight lines, seating and the sun’s position at high summer
3D rendering of the golden spiral for Forbes Garden Project

Author: Jacob Essig

Project by: Sigrid Adriaenssens & Tim Michiels

read part 2 | read part 3