<p>Rammed earth is a traditional earthen construction material widely used in the Auvergne-Rhône-Alpes region of France. It acts as a thermal and hygroscopic buffer; however, its relatively high thermal conductivity limits its compliance with current energy performance regulations. To meet these standards, additional insulation is often required. Nevertheless, due to the strong hydro-mechanical coupling inherent to rammed earth, particular attention must be paid to the choice of insulation system. The assembly must maintain a proper moisture balance to ensure the long-term durability and mechanical integrity of the structure. The objective of this study is to identify suitable insulation solutions for rammed earth walls, based on scientific literature and professional practice, while considering moisture- related risks, thermal performance, and environmental impacts. The analysis is carried out at two steps: first, by examining the intrinsic properties of rammed earth and potential insulation materials individually; and second, by evaluating their performance within assembled rammed earth-insulation systems, taking into account additional factors such as implementation, material interface and surfaces finishes. Despite numerous studies, knowledge gaps remain regarding, interface behaviour, selection of hygroscopic and capillary insulation materials and real-scale behaviour.</p>