Strategies for enhancing the accuracy of evaluation and sustainability performance of building

Abstract

In recent years, considerable efforts have been devoted to minimizing the environmental consequences from building industry globally, as the industry is notorious for its significant resource consumption and environmental emissions. However, due to a lack of data representativeness in many parts of the world, considerable variations were observed among studies, and thus makes life cycle assessment (LCA) results difficult for the decision-making purpose. In addition, the selection of low impact materials and the management of end-of-life building waste are the most important concern. By considering several strategies including data representativeness, low carbon material, and end-of-life building waste management, this study aimed to enhance the accuracy of such assessment and sustainability performance of building. An integrated LCA framework is proposed for implementing those strategies through a case specific high-rise residential building in Hong Kong. Based on case-specific/regional data, carbon emission of building was evaluated with a cradle-to-construction system boundary with the functional unit of 1 m2 of gross floor area using the IMPACT 2002+ method, and then compared to that of selecting generic databases under different scenarios. The results demonstrate that the application of case-specific and generic data would significantly influence the outcomes of the case study, as the deviations of certain magnitudes were mostly derived from different building materials that it can lead to an underestimation of carbon emissions of up to 28%. Along with using alternative materials, the adoption of the proposed materials cycling and resource recovery approach at the end-of-life building could lead to a reduction of 14% of the total emissions (i.e. excluding the use and renovation of building). The results would support data selection for accuracy of evaluation which can be used as benchmark where recognized database is not available and promote sustainability performance of buildings locally, while the proposed framework could be adopted for comprehensive evaluation globally.