This chapter introduces the concept of Extremely Modular System (EMS), and presents an example—Pipe-Z (PZ). Although PZ is a parametric design system comprised of only one module, it allows to create complex spatial single-branch structures, represented here by mathematical knots. The Pipe-Z module (PZM) is introduced and its parametrization is explained and illustrated. An algorithm for automated PZ structure generation based on alignment of PZMs along given spatial curves is introduced. The procedure is illustrated with trefoil, pentafoil and figure-eight knot. The problem of self-intersections and minimization of diversity of the twist angles are briefly discussed.