Nowadays, the need for reducing energy consumption and environmental impacts of building highlights the benefits of bio-based building materials such as hemp concrete. Indeed, hemp is a renewable resource which stores CO2, one of the main greenhouse gas. Moreover, the porous structure of hemp concrete would lead to a typical hygrothermal behaviour allowing good thermal insulation and potential hygrothermal comfort regulation. A previous study carried out in Laboratoire Materiaux et Durabilite des Constructions de Toulouse (LMDC) laboratory led to the development of an innovative pozzolanic binder associated with hemp shiv to design a precast block for wall construction. The present work aims at measuring the thermal properties of precast hemp concrete. Heat capacity is assessed through effusivity measurement and differential scanning calorimetry method (DSC) on the separate components while thermal conductivity measurements are carried out with both guarded hot plate method and hot wire method. The assessment of the thermal conductivity of hemp concrete for increasing water contents is also performed with this latter method. These data are required inputs for numerical model developed in the second part of this project.