This is an edited transcript of a lecture given to master’s students at the Geneva School of Architecture. The question was simple: how far should a building material travel?

Our answer, for most projects, is eighty kilometres. It is not a law. It is a habit that changes the way we design from the first sketch.

Why eighty kilometres

• It is about one hour by truck, so local suppliers can deliver within a working day.

• It keeps us close to the quarries, forests and brickworks we visit.

• It forces the design to follow what the region knows how to build.

Slowness is not a lack of ambition. It is the time a material needs to be understood.

Brick as a teacher

Brick sets a rhythm. Every opening, every corner and every height becomes a number of courses. Students often see it as a constraint. We see it as a way to keep a building calm.

At the Rue Garibaldi Offices, the brick came from a works forty kilometres away, and the bricklayers helped us set the joint width on site.