How Buildings Learn: What Happens After They're Built

by Stewart Brand

Chris Alexander believes in making models. Not just one fancy presentation model but whole lineages of rough models, with everyone who will use the building getting a chance to study and critique the best of them as they evolve. Gradually the models grow in scale until they are life-size and at the site—chalk lines on the ground or the floors, tentative portions of the building jury-rigged of cardboard or cheap plywood. Opulent buildings like the Library of Congress or the Bundestag building need proportionally elaborate models to test for potential folly. Computer modeling and simulation can be helpful, but it can also misdirect designers toward illusory “optimal” solutions. These are inevitably brittle—they work only under one set of conditions. Computer-aided design (CAD) has led to weaker building that can’t handle unusual circumstances such as hurricanes. Before computers, engineers dealt with uncertainty by building in a large safety margin. They were right. Oversize your components.