A comparative life cycle assessment approach of two innovative long span timber floors with its reinforced concrete equivalent in an Australian context

The building sector contributes 24% of the total greenhouse gas emissions in Australia. This is expected to rise by 110% by 2050. Consequently, there has been an increased demand for more sustainable building materials which can play a significant role in reducing carbon emissions. Engineered timber wall and floor panels are being seen as a viable alternative for multi-storey buildings for both strength and environmental purposes and are gaining popularity in Europe, North America and New Zealand. A number of previous Life Cycle Assessments (LCA) comparing timber and concrete mid-rise buildings have highlighted the environmental benefits of using timber, particularly during material production and on-site construction stages. Furthermore, the choice of endof-life scenario had a significant effect on the LCA outcome. The objective of this paper is to compare the environmental impacts associated with alternative designs for a long span floor in a multi-storey building in Australia. The comparison, using an LCA approach, is based on a recently built long span Timber Concrete Composite (TCC) floor in a University building in Sydney. Three design options are considered: the original design of TCC, a Cross Laminated Timber (CLT) panel, and a traditional in-situ reinforced concrete (RC) slab. The CLT and RC designs were conceived with reference to the floor plans and structural loads obtained from issued-for-construction drawings. With this evaluation, recommendations for increasing the competitiveness of CLT and TCC within the Australian market are made