To fulfil the requirements of the new environmental standards in the building sector, increased use of materials containing vegetable particles (hemp) is expected. The manufacturing process of these materials has not yet reached the industrial stage which requires control of the drying process. The objective of this work is to study the various mechanisms of heat and mass transfers occurring during the drying of lime-hemp materials. A macroscopic model has been developed and solved numerically. In order to obtain the moisture transport coefficients, an optimization algorithm was used, allowing the estimation of parameter values by minimising an error criterion between simulated and experimental observations.