Below is an excerpt of a conversation I had with my friends, Maja Trudel (M), and Johann Reble (J), when they were guests in my home last spring. Maja and Johann are young Swiss architects, and it was pleasure to talk with them about building, cities, space and perception. Here’s the part about grids: J: What I was thinking about for a long time is that there are very different scales of structures in the city. A building can be destroyed at any time when you don’t want it anymore. Maybe the structure didn’t fit anymore, maybe it’s the façade people don’t like anymore, and it’s just cheaper to tear down the whole building and build a new one. Look at New York. New…