The realization of freeform shapes in contemporary architecture has sparked research on its mathematical and algorithmic foundations. This area, now often referred to as Architectural Geometry (AG), has close connections to Discrete Differential Geometry (DDG) [1]. The transfer of ideas and inspiration goes in both directions: Practical requirements in freeform architecture led to new concepts in DDG and known concepts in DDG turned out to have applications in architecture [5]. Here, we will discuss some patterns arising in architecture and design which are constrained by requirements on their fabrication and function.