The frequency selectivity of an array of triple cross elements fabricated using an additive manufacturing technique is assessed, to demonstrate the feasibility of using three-dimensional (3D) printing techniques in frequency selective structure production. The process is a candidate for the fabrication of frequency sensitive components in buildings, in situations where the electromagnetic architecture is an important consideration. As a simple symmetrical 3D element, the triple cross is part of a class of elements suitable for crystal-like configurations. The basic performance of the array is summarised through simulations and experimental results.