Efficient use of energy in residential settings can be applied to several areas such as heating, cooling, and lighting. Research has shown that effective allocation of energy resources can lead to significant cost savings and reduced environmental impacts. Passivhaus is a construction standard that has been shown to reduce heating and cooling loads by constructing a highly insulated and airtight building to minimise the heat loss and maximise the heat gain. Different materials have varying R-values that can affect the thermal performance of a residential building. This paper aims to provide designers with a quantified measure to gauge the effectiveness of various insulation material in the real-life applications. Firstly, a Building Information Modelling (BIM) model of an actual residential Passivhaus building is created as an optimisation platform. Then, energy simulation is conducted to measure the building’s base energy performance. Different insulation materials with varying thicknesses will be used to create case scenarios. For each case, energy modelling will be employed to analyse the impact of the changes to insulation on the total energy consumption. Based on the achieved results, as the thickness of the insulation materials increases, their k-value of the insulation material has less impact on the overall thermal energy consumption. It is also found that there is highly correlated relationship between a material’s R-value and the total thermal energy consumption of the building. Future research into this topic may offer more cost-effective and energy-efficient solutions through optimal implementation of insulation materials.