Building The Tower of Babel With Waste Paper Bricks

A team of students from ETH Zurich has developed an unconventional building material: “bricks” made of pressed paper, which they used to build a temporary wall on the Hönggerberg. A film documenting the path from the idea to its realisation will help decide whether their project wins the international competition “Tower of Babylon”.

Students building their “Tower of Babylon” – a symbol of sustainability and the conservation of the supposed waste materials’ value.

Photo: Aurel Martin

Anyone who happened to walk past the architecture building on the Hönggerberg the weekend of 11/12 June may have been surprised to see twelve students building a spiral-shaped wall.

Do they teach brick-laying on an architecture degree these days? No, the creation was actually the makings of an ETH-Zurich entry in the international student competition “Tower of Babylon” (see box).

"Building The Tower of Babylon" Project, ETH Zurich from pascalon Vimeo.

Twelve students from ETH Zurich, including architects, environmental scientists and civil engineers, competed against four teams from India, the USA, China and Singapore with their piece. The aim of the game: to design and implement a structure using local materials within a semester that addresses sustainability in a global context and at the same time creates a symbol for the country, region and local university campus.

Campus’s waste paper as raw material
The teams each had a maximum of four months and a total of 1,000 US dollars for materials for the project. Between April and the beginning of June, the team from ETH Zurich hashed out an idea and design for their “Tower of Babel” in hours of meetings (see ETH Life from 5.5.11). Eventually, they all settled on the idea of using the waste paper that accumulates at ETH Zurich every day for their tower.

“We wanted to find ways to preserve the value of the waste for as long as possible through a series of transformations,” says Pascal Hendrickx, the spokesman for the student team. He and his colleagues collected 720 kilograms of waste paper and cardboard at the departments of chemistry and architecture in the space of a few days. According to the Department of Health, Safety, Security and Environment, that’s roughly the amount of waste paper produced in half a day throughout ETH Zurich.

Stamping with home-made hand press
The students then fashioned an unconventional building material out of the paper by hand: brick-shaped blocks made of waste paper. The team chopped up the waste paper they had collected with a large shredder, then mixed the paper and cardboard snippets with water in a large drum to form a pulp.

Paper Brick Production, ETH Zurich from pascal on Vimeo.

In a press they had made themselves out of slabs of concrete formwork, the pulp was pressed into “bricks” portion by portion: 450 in all, which were then dried for two or three days (the students did not have any more time than that since the rules of the competition stated that the building materials had to be produced and the structure built and dismantled all in the same week). Using the still-damp paper blocks, the team built their “Tower of Babylon” the Sunday before last – a spiral-shaped wall measuring three metres in height and 6.6 metres in length.

The finished product is neither a tower nor does it boast an unusual shape or any creative ambitions. “For us, it wasn’t so much about the structure’s design as creating a building material by hand out of waste,” explains Hendrickx. The wall might seem modest, but the team calculated that a wall eighty metres high and 180 metres long could be built with the amount of waste paper ETH Zurich produces each year – and with that of the City of Zurich, even one measuring 500 by 1,140 metres.

Preservation of value over and above wall
The paper wall is already history; it only stayed up for a day. According to the rules of the competition, the structures also had to be torn down the same week it was built. For Hendrickx and co., however, the paper bricks are to retain their value for a little while longer: they want to reuse them to make furniture. And if that doesn’t work, they will be put to good use as briquettes for heating purposes. The last few days have been all about documenting the project with a film, photographs and a detailed description of the idea and its realisation.

Based on this, an international jury of artists, architects and scientists will now select the most convincing structure in terms of creativity, quality, relevance to the theme “limits – large problems of our society” and presentation (among other things). The initial images from the other four teams showed some designs that, on the face of it, looked more spectacular than the paper wall, says Hendrickx. Nonetheless, he is confident that the philosophy behind his team’s project will impress the judges.

The team documented the whole production and construction process for “Tower of Babylon” on a video.