Breaking the damp greyness lingering between two dark, industrial exhibition halls in Kortrijk, Belgium is the architect Mats Karlsson’s strikingly bright, foldable and environmentally friendly tunnel Xile. Built as a passage between two venues, this tunnel of light brings practicality, environmental sustainability and outstanding design together and challenges the traditional divide between functionality and beauty. “I appreciate practicality, I want there to be a thought behind a creation. But the practical features have to contribute to the overall concept. I wanted a combination between practicality and visual aesthetics.” says Karlsson about the project.

The idea behind the 35 meter long tunnel was to connect two buildings with light-weight, low-cost, removable and recyclable materials and to create a bright, eye-catching walk for the over 100,000 visitors of Interieur 06, one of the largest design fairs in Europe, taking place every second year. The result is a self-supporting system, based on origami, made up of large, 4.5mm thick folded sheets mounted next to each other and sealed with 3m tape.

Although Xile is made entirely from the recyclable, extruded polypropolene, the original construction was born out of experiments with cardboard. It was during a research trip to Shanghai, where Karlsson, then a design student, got inspired to create a foldable piece of architecture. On his return to Sweden, he started developing the idea at a number of Stockholm art institutions and became fascinated by the flexibility of treated paper as a building material. “I instantly visualised a three-dimensional piece of work. I started building it on the computer in order to develop a self-supporting construction.” says Karlsson. But the development of the project proved a painstaking process and Karlsson had to collaborate with a researcher at Stockholm University in order to develop the mathematic calculations necessary to ‘break the code’, as he puts it, for the final product.

Karlsson kept the idea of the cardboard constructions in the back of his head until the organisers of Interieur 06 approached him with the challenge of how to creatively connect the two exhibition halls. For the task, he needed an inexpensive material that could be produced in large, thin pieces. “Paper has a direct, natural feeling that is recognisable and very accessible. It’s inexpensive and fun to work with as you can fold it, bend it, push it and mould it into shape. Plastic, on the other hand, has a great range of features for this project with its transparency and what that brings to lightening effects.” says Karlsson on his choice of material. The result is an adaptable, flexible and transformative object with an interesting form, fascinating in its interaction with light, natural or unnatural, that has a dramatic effect on its surroundings. “I wanted to create the experience of something that is in between being outside and inside.” he explains.

Once the physical challenges of the construction were overcome, the next step was to make the light interact positively with the uneven structure of the tunnel. Karlsson started folding small-scale paper prototypes in order to create shapes that break the light in aesthetically pleasing ways.


“Something happens when a pattern is repeated to what seems like eternity. One slowly starts noticing how the surroundings, especially the light, create change and variation. It creates very powerful effects.” To emphasise its unique shape and form, Xile is lit from the outside by powerful, oversized spotlights, creating a space of dazzling, intense brightness that adds to the pleasantly disorientating experience brought by the many twists and turns in this dream-like, milk-white, almost transparent plastic tunnel. Produced in Sweden, the final product was folded and shipped to Belgium and erected on metal rails between the two halls, creating a science fiction-like transit experience. 


The versatility of both the inexpensive material and the flexible design has created interest from several directions and Karlsson is currently working with help-organisations and investors in order to provide temporary shelter in disaster areas as well as student accommodation and lodgings for homeless people. Additionally, due to the tunnel’s superior acoustics, plans are under development for using the design at festivals, events and parties. Karlsson also hopes to be able to extend the concept vertically and expand the construction into several rooms and floors. “There are many opportunities for developing and extending this idea” he says, I don’t want to pose limitations, I leave that to the users.”

The article was published in the Forum AID Awards Supplement 2008

”The concept for Xile is already a design classic.  Xile can be used both indoors and outdoors; it’s flexible and becomes an object wherever it’s placed. There is something transformative about Mats Karlsson’s design that also has a dramatic effect. This is a cost-effective construction and it’s designed in a way that responds well to present demands for sustainability. This in combination with Xile’s accessibility an the fact that the idea behind the design can be understood by everyone who sees it makes Mats Karlsson’s Xile a natural winner in the interior category of the Forum AID Award.”