The aim of the research was to manufacture a brick from recycled high-density plastic using processes of mechanical recycling, thermopressing and thermoforming. The final result was the development of an experimental design methodology and the manufacturing of a LEGO®-type brick for use in self-assembly modular wall construction. This research by design of an adaptable architectural brick component, provide a film as semi-finished product with a thermal conductivity of 0.103 W/mK and a mechanical characterization by a compression test in which none of the HDPE-based components shows apparent deformation.