The diagram is a virtual machine enacting between the architect and an end product. It brings order to the essential elements of architecture through the forces that are bound within it; waiting to be set by the architect. It outlines possibilities of worlds; sets modes of relations in-between program, context and structure. It stands against a structure of hierarchy, a linear mode of relations or a point of origin. It is generative, performative and non- representative. The Nine Square Grid is a three by three square grid. It is a grid framed within a grid, a stage without a play, a canvas without the painting. It is detached from any type and style; pointing to itself and nothing but itself. This book is a study on understanding how the Nine Square Grid becomes a diagram. It outlines the diagram, the Nine Square Grid, and how the Nine Square Grid acts as a diagram. The reader is equipped with adherent concepts to subjects and objects while a variety of samples from architecture is collected. Through the concepts and examples, the book explicates how the Nine Square Grid acts to generate architectural form and how it repeats itself as mere type.