Walk Appeal promises to be a major new tool for understanding and building walkable places, and it explains several things that were heretofore either contradictory or mysterious. It begins with the assertion that the quarter-mile radius (or 5-minute walk,) which has been held up for a century as the distance Americans will walk before driving, is actually a myth.
Both images below are at the same scale, and the yellow dashed line is a quarter-mile radius. On the left is a power center. As we all know, if you're at Best Buy and need to pick something up at Old Navy, there's no way you're walking from one store to another. Instead, you get in your car and drive as close as possible to the Old Navy front door. You'll even wait for a parking space to open up instead of driving to an open space just a few spaces away… not because you're lazy, but because it's such a terrible walking experience.
The image on the right is Rome. The circles are centered on the Piazza del Popolo (North is to the left) and the Green radius goes through the Vittorio Emanuele on the right. People regularly walk that far and then keep on walking without ever thinking of driving.
The details of a building cannot be made alive when they are made from modular parts
If the builder wants to build the room from modular four-foot panels, he must change the size of the rooms, and change their shape, to fit his panels.
In such a building system, it is impossible for a person to create a plan which reflects the larger subtleties of site or plan. Each plan will always be chopped and disfigured to make it fit the building details.
To make the building live, its patterns must be generated on the site, so that each one takes its own shape according to its context.