GENEVA — The brand-new glass door to the office is marked DPA — for Dominique Perrault Architecture. The renowned French architect has hung his shingle in Geneva, specifically on an unattractive street in the industrial outskirts, near the Vernier oil warehouses. 

For the designer of France’s National Library building, the start of the academic year has been very Swiss. A mixed-use tower in Fribourg, a new neighborhood around the train station in Lugano-Muralto and a complex development in Zurich.

He is also joining the faculty of the Lausanne Institute of Technology, but not just to be near his various Swiss projects. He is the inaugural appointment to a new chair dedicated to underground architecture. It’s a promising domain in Switzerland, where buildable land is nearly exhausted.

“Ignored and rejected, what’s below our cities is a vital treasure,” school officials said in announcing the new chair. Le Temps spoke with Perrault to learn more about the possibilities of underground developments.

Le Temps: How did this interest in underground construction come about, and how have you explored it over the course of your career? 

DOMINIQUE PERRAULT: In hindsight, I see a connection between the architectural concepts that I’ve worked on extensively, the majority of which have been completed. At the French National Library (completed in 1995), you only see the tip of the iceberg. Three-quarters of the building’s volume is underground, and the gardens are 14 meters below the surface of the Seine. The velodrome and olympic pool in Berlin (1999) were even more radical. From ground level, you only see the roof, and there is an apple orchard planted around it. More recently, the Women’s University of Seoul (2008) is a valley dug into a hillside. We are always constructing a landscape

When we are talking about underground architecture, it sounds like it’s better to talk about a concrete discipline, not a utopian vision?
You could push it to utopia, but it’s really a very pragmatic discipline. By building underground, the Women’s University in Seoul was able reduce its energy use by 60 percent compared to a traditional building, thanks to the insulation provided by the soil and Canadian well technology that allows the building to use natural heating and air conditioning. That’s the ecological advantage of this type of construction. The other major advantage is to free up surface space to prevent the built world from expanding to infinity. 

The Lausanne Institute of Technology has also developed the concept of a “Deep City” to take advantage of buildable spaces underground. Are these two components of the same discipline?
They complement each other. There has barely been any coherent theoretical development regarding the subterranean, just very fragmented approaches. The “above” and “below” camps are quite separate today, but that was not the case in 19th century cities. Haussmanian Paris developed a harmonious relationship between the services above ground and the networks in the basement. Cities need to re-discover that harmony. We can create more density by building up, but also by building underground. Underground density has the advantage of being invisible and not causing the city to lose breathing room. Quite the opposite — it creates empty space. 

What should be put in the basement?
At the base of buildings, at a depth of up to 10 or 20 meters, we can put complementary services. Or storage facilities — for example for packages for an e-business — for whom the current delivery system requires intense traffic from polluting trucks. We could get the merchandise closer to its destination. 

You also envision applying subterranean building to residential buildings, but how exactly?
In our project in the industrial region of Geneva, we are developing a web of apartment blocks with a central garden that is one floor below street level. That is already underground! The apartments will look out on the garden from one floor higher than they will look out on the street, which will make for very handsome residences. We’re on even terrain, but it doesn’t create a feeling of vertigo. It’s not about creating anxiety. We have lost our relationship with the ground by building everything totally flat. The ground has become a part of the landscape that is reserved for cars and machines. But we come from the earth and we shouldn’t be afraid of it. We celebrate our reunion with the ground!

Should cities develop a plan for underground urban development as opposed to piecemeal underground construction?
Absolutely! Osaka and Montreal both know how to build an underground city, undoubtedly because of the cold. Here, we are learning to transform subway stations into urban environments. That’s what we are doing at the moment at the Naples train station, making natural light penetrate 40 meters below ground. The underground network is too frequently developed in isolation.

What specifically are you going to teach at the Lausanne Institute of Technology?
I would like to allow young architects to widen the field of their discipline, to invest in the subterranean as an element of urban life, of architecture and as an element of environmental quality. Perhaps the basement, which is often a rejected space, can be brought to the forefront.  

The Lausanne Institute of Technology has just completed a sprawling extension, called the Learning Center, that is not exactly an example of an economic use of the ground. Would you have built it differently?
No. It’s important to have visible connections between the fields of instruction on a campus. In addition, the building plays with the terrain as well, because you can walk underneath it. But my students and I are working on subterranean spaces on campus meant for common use. I am going to invite civil engineers, doctors and biologists to holistically address the underground city and its viability.