In order to reduce the consumption of energy and the emissions of greenhouse gases and CO2 generated by the construction industry, bio-based concretes made of plant aggregates are increasingly used in the optimization of building envelopes, thanks to their good hygrothermal performances, their renewable origin, and biodegradability. The present study focuses on the effect of combining different proportions of rice straw (RS) with rice husks (RH) on mechanical and hygric, and thermal properties of straw/husk concrete. The experimental investigation seeks to evaluate the thermal conductivity, moisture buffer value (MBV) and mechanical compressive properties of these concretes. The results evidences clearly that it is interesting to associate these two residues. The thermal conductivity of the bio-based concretes slightly decreases with increasing rice straw content and rises almost linearly with concretes density. The MBV measurements reveal that rice straw confers to concretes an excellent moisture buffering capacity. Finally, the compression test results highlight that the addition of rice straw induces high deformability and enables concretes to store a high quantity of energy.