Life cycle energy of steel and concrete framed commercial buildings

The construction and operation of buildings are vastly responsible for significant environmental impacts, predominantly through resource consumption, waste production and greenhouse gas emission. Environmental issues continue to become increasingly significant and hence the building operational energy efficiency and the energy required for construction and consequently, for the material production, are getting greater importance. The commercial buildings in general consumes significant amount of materials in construction and consumes significant amount of energy during operation. Therefore it is essential to determine both embodied energy and operational energy. This paper quantifies and compares the embodied energy and operational energy of concrete and steel framed structures, which are commonly used in commercial buildings. A typical high rise office building in Melbourne has been chosen for this exercise. The studied building is a fifty storey with a flat roof and the total net-lettable area of 75 570 square meters. The embodied energy contribution of the substructure, the super structure with the structural elements namely foundation, beams, columns roof, facades and stairs are investigated. The results shown that the structural building materials, concrete (with steel reinforcement) represents the largest component of embodied energy for concrete frame structure while the steel framed structure examined showed the beams represent the largest component of embodied energy. It was fond that there is no significant difference in operational energy.