Due to climatic changes occurring during the last decades, extreme temperature deviations are observed throughout the year. These changes may cause considerable damage to the hot/cold water piping assembly by the continuous thermal expansion-contraction of the piping material leading to crack initiation and finally the rupture of the pipes over time. This study focuses on the preparation and characterization of materials, which present low thermal expansion and enhanced mechanical properties. Polypropylene Random copolymer (PP-R) is used widely as a piping material. To address the issue of dimensional stability, PP-R multilayer pipes are reinforced with a filler (most commonly Glas Fibers at large amounts) reducing their thermal expansion. The main goal of this study is the development of PP-R composites using fillers at low contents, enhancing the dimensional stability together with PP-R’s mechanical properties. Two sets of PP-R nanocomposites were prepared, containing SiO2 nanoparticles and Montmorillonite nanoclays (MMT), respectively at various loadings (1-15 wt.%). The prepared materials’ morphological characterization was conducted using Scanning and Transmission Electron Microscopy (SEM, TEM). Thermal stability was estimated by Thermogravimetric analysis (TGA), while the melting and crystallization behavior was evaluated by Differential Scanning Calorimetry (DSC). A dilatometer was employed for the thermal expansion measurements. Tensile tests were carried out for the mechanical properties characterization of neat PP-R and its prepared nanocomposites. The incorporation of the nanofillers in the PP-R matrix induced enhanced dimensional stability while the elastic modulus of the PP-R/SiO2 nanocomposites increased considerably for low filler contents (1-2.5 wt.%). Acknowledgments Financial support provided by the Operational Program Competitiveness, Entrepreneurship and Innovation (EPANEK 2014-2020/Action RESEARCH–CREATE–INNOVAT, project code: T1EDK‐02575).