The main objective of this document is to build on the U-space blueprint, the Master Plan and the U-space Concept of Operations by providing a first view about the principles for the U-space architecture. These principles will guide the U-space projects in their implementation and in their final reporting, as well as supporting U-space implementers by establishing a common approach to defining and realizing U-space. These principles will also be embedded in the U-space CONOPS whenever needed.