Nowadays, many fields such as aeronautics, transport, nuclear are more and more involved to elaborate materials which can resist at extreme and high temperature. Therefore, the development of a fire barrier which could be formed at right time and reacting accordingly against thermal and fire constraint becomes essential. To create this fire barrier different ways can be considered. The standard approach consists of changing the chemistry and formulation of material by incorporating flame retardant agents to improve the fire protective performances. But the development of novel chemistries becomes harder and harder. In this work, a new way of thinking is contemplated. Instead of changing the material formulation, the design and the layout of materials are tested to reach the optimized fire protection performances. To do this, thermocompression, which is a classical polymer shaping process, does not easily allow designing sophisticated shapes without using a complex mold, on the contrary to 3D printing (or Polymer Additive Manufacturing (PAM)), which is a very flexible technique. Among all 3D printing techniques, Fused Deposition Modeling (FDM) is of high potential for product manufacturing, with the capability to compete with conventional polymer processing techniques. Classical FDM is a quite low cost technique, but the range of filaments commercially available is limited and costly. However, in some specific 3D printing processes, no filaments are necessary. Polymers pellets feed directly the printing nozzle allowing to investigate many polymeric matrices with no commercial limitation. This is of high interest for the design of flame retardant materials, but literature is scarce in that field. In this work, different designs of flame retarded materials have been investigated to highlight the benefit of this new processing technology. Firstly, homogenously flame retarded samples have been considered (bulk treatment) and the comparison between the performances of samples prepared by thermocompression and 3D printing has been done based on four different Ethylene-vinylacetate copolymer (EVA) formulations containing aluminum trihydroxide (ATH) or expandable graphite (EG) (EVA, EVA/ATH (30 wt%), EVA/ATH (65 wt%) and EVA/EG (10 wt%)). Then, new concepts and designs of multi-materials have been proposed to optimize the fire protection properties by changing the design. Samples presenting flame retardant additive concentrations gradient is prepared, as well as multi-layer samples containing flame retardants of different modes of action. A full characterization of the thermal protection properties of these novel 3D designs will be presented. This work is a pioneering innovative study for exploring the feasibility of using FDM technology to design new and efficient flame retarded materials, offering the way to make safer materials at low cost.