AUTHORSCrawford, Robert H
CATEGORIES2022 Conference Papers Conference Papers
Architects and other construction industry professionals are increasingly seeking to reduce the embodied greenhouse gas (GHG) emissions of construction projects. To support this goal, reliable and comprehensive data is needed on material performance. There are various sources of this data currently being used, including Environmental Product Declarations (EPDs), and material life cycle inventory (LCI) databases, such as the Environmental Performance in Construction (EPiC) Database. Many LCI databases rely on manufacturer-specific data (common also with EPDs) but suffer from inherent data gaps. The EPiC Database is unique as it uses macro-economic input-output data, as part of a hybrid approach, to fill the gaps in LCI and EPD data to ensure comprehensive supply chain coverage. Due to this, data can vary considerably between EPDs and the EPiC Database. However, no study has compared these two data sources. The aim of this study was to compare the embodied GHG emissions coefficients provided by EPDs and the EPiC Database and assess the effect on material selection decisions. EPDs for Australian ready-mix concrete products were analysed and compared to hybrid GHG emissions coefficients for equivalent products within EPiC. It was shown that while hybrid coefficients are generally always higher than coefficients from EPDs, the overall trend between products was relatively consistent. On average, EPD coefficients represent 78% of the equivalent hybrid coefficient, ranging from 38 to 115%, highlighting the incompleteness associated with EPD data. The large variability in GHG emissions coefficients between EPD products of similar type means that product specific EPD data may not provide any more guidance to material selection than what the generic EPiC product data provides. EPiC data may provide very useful initial guidance for material selection, while comparison of materials based on EPDs from different manufacturers may be misleading, also questioning the compliance of EPDs with the requirements of the international standard EN 15804.
Keywords: Embodied greenhouse gas emissions; environmental product declaration; EPiC Database; hybrid life cycle assessment.