Christopher Alexander
A great book detailing some widely applicable ways to design building, and why. Taken from studies conducted by Alexander and his architectural students and colleagues from The Center for Environmental Studies at the University of California, Berkely.
The first book in a series of three, Timeless sets the framework to a pattern language, establishing first that the best possible way to go about building a building is the way that people have done it for ages, simply and naturally. The qualities of almost all buildings most appreciated today come from this timeless way.