Enhancing the effectiveness of insulation to reduce energy consumption in HVAC systems plays a crucial role in achieving lower energy usage, decreased carbon discharge and enhanced ideal thermal condition in sustainable energy efficient construction, while phase change materials (PCMs) offer an innovative approach to energy storage, its effective heat transmission can be a solicitude when used in building applications. Traditionally, PCM selection has focused on properties such as enthalpy of fusion latent heat of fusion and transition temperature. However, the impact of PCMs on building energy performance resulting from changes in thermal conductance (k), compactness (ρ) and heat retention capacity (Cp) remains poorly understood. To address this knowledge gap, this study evaluates dual PCMs with shift temperatures over and beneath atmospheric temperatures when integrated into extremely permeable pliable styrofoam utilizing a linear-dimensional (1D) foam center panel model in COSMOL Multiphysics. Tests were conducted for the solstice season in a hot mediterranean climate with an ambient temperature of 33C. The results suggest that, in addition to latent heat, PCMs can help mitigate the increased thermal conductivity of Styrofoam-PCM composes, thereby enhancing effectiveness of the insulation capacity. Edifice energy modelling utilizing energy plus, with the foam center integrated into a panel of insulating structure (PIS), demonstrating the utilization of PCMs, irrespective of shift point, can result in yearly electricity savings of 10-25 %. These savings are particularly notable during the cooling season in summer.