By Interlaced Space Structures (ISS) we mean a coupled system of naturally curved flexible panels/strips interlaced together according to a design pattern. We are looking for a physically-based and efficient form-finding procedure in order to interactively explore different interlaced morphologies with respect to the design parameters for structural design purposes. Each panel is considered as an inextensible discrete Kirchhoff rod and the rest shape of the coupled system rods is obtained via a constrained total energy minimization. The interlacing pattern is translated into a set of overlap order constraints and applied to the optimization problem. We employ an implementation of the interior-point filter line search algorithm with the Quasi-Newton procedure to solve the constrained nonlinear optimization and discuss the results through a case study.