Prefabrication is one strategy considered to provide improved environmental performance for building construction. However, there is an absence of detailed scientific research or case studies dealing with the potential environmental benefits of prefabrication, particularly the embodied energy savings resulting from waste reduction and the improved efficiency of material usage. This paper aims to quantify the embodied energy of modular prefabricated steel and timber multi-residential buildings in order to determine whether this form of construction provides improved environmental performance over conventional concrete construction methods. Furthermore this paper assesses the potential benefits of reusability of materials, reducing the space required for landfill and need for additional resource requirements. An eight-storey, 3943 m(2) multi-residential building was investigated. It was found that a steel-structured prefabricated system resulted in reduced material consumption of up to 78% by mass compared to conventional concrete construction. However, the prefabricated steel building resulted in a significant increase (similar to 50%) in embodied energy compared to the concrete building. It was shown that there was significant potential for the reuse of materials in the prefabricated steel building, representing up to an 81% saving in embodied energy and 51% materials saving by mass. This form of construction has the potential to contribute significantly towards improved environmental sustainability in the construction industry. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.