The octadecane/exfoliated graphite nanoplatelets (xGnP) shape-stabilized PCM (SSPCM) was prepared by impregnating octadecane as the PCM into xGnP in a vacuum. Fourier transform infrared spectroscopy determined that the heat storage characteristics of octadecane could integrate into the structure of xGnP due to its physical bonding, without a change in its chemical properties. Scanning electron microscopy images revealed that octadecane was evenly dispersed in the pores of xGnP Differential scanning calorimeter analysis displayed that the melting temperature range of the SSPCM was similar to that of pure octadecane. Thermo gravimetric analysis measurements of the octadecane/xGnP SSPCM determined that the percentage of impregnated octadecane into xGnP was 55.9%, with 110.9 J/g of latent heat storage energy. In addition, mortar with the prepared SSPCM was investigated, in terms of developing advanced building materials with thermal energy storage properties. The purpose was to improve the thermal properties of mortar by using the latent heat storage of the octadecane/xGnP SSPCM. In consequence, mortar preserved with the SSPCM could be utilized as a construction material that stored thermal energy, to result in saving in buildings energy consumption. (C) 2013 Elsevier B.V. All rights reserved.