We live in a reality where the climate crisis is raging and life expectancy of buildings is in decline. Such crises call for the consideration of unconventional design solutions and therefore unconventional building materials. Shigeru Ban — a Pritzker Architecture Prize winner — is often referenced in design courses for his curved wooden canopies and use of timber in large scale projects, most notably the Centre Pompidou-Metz museum in France. However, his voluntary work addressing natural disasters is prolific. Often called the ‘disaster architect’, Ban’s voluntary projects often make use of an unconventional material: cardboard tubes.

The largest of his temporary structures is the Cardboard Cathedral. It was designed as a transitional cathedral to replace the original cathedral in New Zealand, which suffered the damage of a fatal earthquake in 2011. This particular project responds to design challenges of both temporary disaster relief and large scale, programmatic. For this reason, the Cardboard Cathedral could provide insight for the future usage of unique materials and design approaches.

Carved into the stone of the original church, it is written “let these stones speak of a love that endures forever”. New Zealand is particularly earthquake prone and has encountered 11,000 earthquakes with a magnitude of 2 or more between 2011 and 2013. The stone maintained structural integrity until the 2011 earthquake, resulting in irreparable damage. In this case, how does cardboard replace stone? Shigeru Ban believes that “the strength of the building has nothing to do with the strength of a material”. If heralded as a success, could paper become a normalized material choice for large scale or permanent projects? In search of an answer to this question, we came across the following main ideas.

1. The structural composition of the Cardboard Cathedral is a composite of steel, timber and cardboard.

The initial web browse of the cardboard cathedral might lead one to interpret this as a building primarily made of and supported by cardboard. ArchDaily describes the construction “as a simple A-frame structure from 98 equally sized cardboard tubes and 8 steel shipping containers”. Dezeen writes that “the building features a triangular profile constructed from 98 equally sized tubes”. There is little mention of the actual structural composition.

In a news article published by The Press, it’s noted that while Ban originally intended on using cardboard as the primary structure, as had been done in many of his previous projects, engineers determined a risk of bowing due to wind loads. This prompted the insertion of timber beams which became the primary structural support of the roof. While the overall tone of the report is celebratory, it concludes that the cardboard functions merely as cladding, and its purpose is reduced to a “novel gimmick”.

2. The cardboard is not a primary structural material, nor is it merely just cladding.

It’s a reinforcing material that adds strength under tension.

I had the opportunity to interview Partho Dutta, a senior architect at Populous, who has designed notable large scale projects in earthquake-prone areas of the world, such as the New Delhi International Convention and the New Perth Stadium in Perth. He paid a visit to the Cardboard Cathedral in 2016 when the impact from the earthquake was still very much visible. Roads were closed and certain towns were completely blocked away. When asked about the role of cardboard, he affirmed, without hesitance, that the cardboard did indeed serve a structural purpose. He explained it in this way:

“If you think of a truss, and the way a truss behaves, as opposed to a solid bar of steel, it’s only the edges of the truss that have structural quality, either compression or tension.”

The weighted structural significance between cardboard and wood aside, engineers have noted that both materials are naturally more earthquake resistant than concrete or stone. This is because concrete and stone will have more inertia and momentum due to its heaviness. The flexibility of wood and cardboard implicate that they can absorb shock and in this sense, have more strength under tension.

3. Budget, accessibility, and sustainability, in addition to structural integrity, may be of comparable importance depending on project type.

Locally sourcing materials is normally a priority in disaster relief projects due to the need for fast completion, and the potential isolation or road blockage caused by whatever damage. However, the original specified thickness couldn’t be supplied by the local manufacturer and the earthquake damage made it impossible for these tubes to be imported. With these considerations, along with the fact that reinforcing materials serve the function of ensuring additional strength and safety, the claim that the cardboard is merely a gimmick might be cursory.

Ultimately, Ban’s design challenge was to provide the community with a place to regain their faith in the cheapest, quickest, and safest way possible, at a time where being able to practice faith was perhaps most poignant. These decisions resulted in a structure that is considered 130% earthquake proof and would last 50 years.

4. The longevity of buildings is becoming deprioritized. The longevity of materials is becoming more essential.

The earthquake damage between 2011 and 2013 led neary 7,000 homes in the Canterbury Region to be demolished and entire suburbs to be wiped off the map. The impact called for restructuring and reshaping of entire communities, including the city of Christchurch and surrounding suburbs. Architects and engineers would likely argue that this calls for a new way of looking at structure and design, and therefore also materials.

Partho Dutta claims that if you can use timber, you can use cardboard. He referenced a proposal he worked on for the 2012 World Cup, which entailed a comprehensive sports complex, including a stadium and hotel, made up entirely of timber. Thinking ahead of timber which is an up and coming material choice due to its sustainability, its life cycle is such that timber will eventually become the ingredient for paper.

At the end of our interview we moved on to the topic of permanency. Dutta emphasized that it is the role of the design team to look for a material to perform to a certain standard. He further stated:

“Here in the US, you mostly look for a 30 year performance level, in Europe and some parts of Asia, it's 90 or 100 years. Very few buildings are built anymore for more than 30 years.”

The main reasons for the decline in expected performance level could be globalization and technological advancement, which causes societies to be more dynamic, more nomadic, and to have new and ever-shifting environmental demands.

5. The climate crisis will continue to change the way we build,

prompting the diversification of an architect’s repertoire of building materials.

Traditionally when we think of the appropriate building materials to use, we think of what is the most long lasting, but if we are starting to accept a more ephemeral way of designing, perhaps it means more freedom to explore materials that might be better suited for nuanced functional demands. At the beginning of my search, I was concerned with how permanent this transitional building was and what that meant. I thought it would be a story about a building that was thriving longer than expected due to cultural attachment to this material that was acquired over time. The truth was that it will likely last for exactly how long it was designed to last and it is the deliberate combination and arrangement of cardboard, timber and steel that will enable it to do so. Additionally, the usage of innovative materials and methods in architecture is not new for the South Island. They have made temporary malls with surplus shipping containers, residential walls with a magnesium oxide / fiber glass composite that optimizes both strength and elasticity, and a lightweight roof for a soccer stadium with ETFE, which also allows sunlight through to grow natural turf.

Natural disasters are not new, and the creative ways that they have been dealt with are not new, but both are becoming more relevant as climate change becomes more pervasive, affecting people across all socio-economic backgrounds and geographical locations. While each decade has been warmer than the last for the past 4 decades, the extreme weather we have experienced in just this past summer was less gradual and unprecedented. We witnessed extreme flooding in Germany that nobody expected to see in 100 years, major heat waves across the Pacific Northwest America in late June, and record-breaking wildfires throughout the summer in multiple regions. The intergovernmental panel on climate change recently released a major report backed by a couple hundred of scientists that reviewed roughly 14,000 scientific papers. According to a reporter from the NY Times, the conclusion from this report is that even if we cut all CO2 emissions tomorrow, we will be facing irreversible warming and subsequently extreme weather, for the next 3 decades. Furthermore, there is a small window of opportunity to reverse the impacts of climate change for our future generations, and that window is now.

While Shigeru Ban’s environmental awareness was anomalous for his generation, and his projects that addressed it were mostly voluntary, the problems that he set out to solve will inevitably be problems that all architects and designers of our generation will have to face, no matter the project type or clientele. As we respond to new functional demands and design for ephemerality, we will naturally have to adopt a more nuanced and diverse vocabulary of materials, paper perhaps being one of them.

Besides, “paper buildings cannot be destroyed by earthquakes”.