This paper describes an investigation on the use of a new composite construction material composed of plaster, sand, crushed gravel and date palm fibres of waste agriculture peels, having mechanical properties potentially useful in technical domains. Thermal conductivity and some mechanical and physical properties are investigated. The results showed that the incorporated vegetable fibres changed the rheological and the mechanical behaviour of the material and increase considerably its ductility, improving its cracking threshold. A decrease in thermal conductivity and bulk density is recorded. Therefore, it seems to be a promising composite for saving energy suitable for renovation purposes. Keys words: Palm, fibres, plaster, thermal conductivity, ductility, composite, concrete, gypsum.