6 ideas
Rasmussen watched boys in Rome play a ball game on the steps and terrace below Santa Maria Maggiore, using the church's wall as a backboard and learning every surface, angle and bounce. Architecture is understood by using it with the body, not by looking at it as an image.
A building can be read as solid masses standing in space or as hollow volumes carved out of mass, and the two readings flip like a figure-ground illusion. Designers who shape the cavity, meaning the room or courtyard or street as a positive form, produce a different experience from those who model objects.
Rasmussen compares the architect to a theatrical producer who stages the lives of people who will use the building for decades. Those users cannot be scripted, so the building has to anticipate their movements and rhythms and support them. A building is judged by how well it accommodates life, not by how it looks as a sculpture.
Repeated elements such as columns, windows and paving patterns set up a rhythm that people feel in their bodies, the way workers fall into a shared cadence while hauling or hammering. A good rhythm is regular enough to be sensed and varied enough to stay alive. People register it through the pace of walking and the movement of the eyes more than through analysis.
The size, placement and orientation of openings decide whether light is diffuse and even, or directional with strong shadow. Raking, concentrated light models form, brings out texture and produces drama, so window design is a decision about how every surface in the room will be perceived.
Every space has an acoustic character that people feel even when they don't notice it: the hard echo of a tunnel, the long reverberation of a stone church, the dead quiet of a padded room. Gregorian chant developed to suit the long reverberation of great churches, so sound and space shaped each other. Materials and proportions therefore decide how a room sounds, and that sound is part of how it feels.