Variability in Embodied Energy and Carbon Intensities of Building Materials Using Hybrid LCA: Malaysian Experience

This paper empirically investigates the variations of embodied energy (EE) and carbon (EC) intensities of materials and identifies their parameter variations in hybrid life cycle assessment (LCA). These parameters include energy tariff, primary energy factor, disaggregation constant, emission factor, and price fluctuation. Hybrid LCA has been conducted to expand the system boundary by filling the gaps in traditional LCA data inventories. The Malaysian Input-Output (I-O) tables are used to derive indirect energy and carbon intensities which are then combined to take advantages of detailed process LCA. The results revealed that maximum increase in energy tariffs and material price fluctuations were the key parameters and issues leading to higher variations in EE and EC intensity values. Other parameters – such as maximum increase in primary energy factor, emission factor and excluding disaggregation constant – have a slight impact upon EE and EC intensity variations. Building materials with high indirect energy in the upstream boundary of materials production have high influence on hybrid LCA variation. Therefore, any decision relating to these materials should be considered carefully.