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This paper publishes the results from a major five year International Energy Agency research project which investigated the reduction of embodied energy and greenhouse gas emissions over the whole life ('cradle to grave') of buildings. Annex 57 collated and analysed over 80 detailed quantitative and qualitative building case studies from the participating nations. For many years the multiple variations in methodological approach of case studies to assess the whole life embodied impacts of buildings have presented a major challenge for politicians and other decision makers. Any real change in design and construction practice has also proved elusive. This paper describes a modified research synthesis and meta analysis as a novel and valid method for drawing meaningful conclusions from large sets of significantly diverse studies. The quantitative analyses consider embodied impacts of the product stage, replacement, and end of life stages, of new and refurbished buildings, and of different building assemblies and construction materials. The product stage is shown to dominate in most cases, with the median value around two thirds of the whole life embodied impacts, with replacements the next highest with a median figure of around 25%; however replacements in five studies were over 50% of the whole life impacts. It should be noted that several life cycle stages are still missing from these studies. The case studies included eleven refurbishment projects, in which energy efficient measures and low carbon technologies were retrofitted to existing buildings; for these projects the median product stage impact was found to be just under half that for the new build projects. While further research is required to compare the operational energy use in the new and refurbished buildings, this suggests that such energy refurbishments have a significantly lower impact than new buildings. Several other studies considered the impacts from technical equipment and internal fixtures and f, QC 20190925

The dominance of operational energy and related greenhouse gas (GHG) emissions of most existing buildings is decreasing in new construction, when primary fossil energy of building operation decreases as result of the implementation of energy efficiency measures as well as a decarbonisation of national energy mixes. Stakeholders therefore have a growing interest in understanding the possibilities for reducing embodied impacts in buildings. In the LEA EBC project 'Annex 57' a broad call for case studies was launched with the aim to identify design strategies for reducing embodied energy and GHG emissions (EEG) from buildings. The aim of this paper is to identify and provide a collected and comprehensive overview of quantitative reduction potentials of the particular EEG reduction strategies which should be considered by the stakeholders engaged in, and with the capacity to influence the outcome of, individual building projects. This is done by a systematic analysis of the Annex 57 case study collection as well as additional scientific literature. While it should be noted that the actual EEG savings at building level illustrated in this collection of studies are only applicable to each specific case, importantly this multiple cross-case analysis has provided rigorous evidence of the considerable potential to reduce embodied impacts in the design and construction of new and refurbished buildings., QC 20180426

The importance of embodied energy and embodied greenhouse gas emissions (EEG) from buildings is gaining increased interest within building sector initiatives and on a regulatory level. In spite of recent harmonisation efforts, reported results of EEG from building case studies display large variations in numerical results due to variations in the chosen indicators, data sources and both temporal and physical boundaries. The aim of this paper is to add value to existing EEG research knowledge by systematically explaining and analysing the methodological implications of the quantitative results obtained, thus providing a framework for reinterpretation and more effective comparison. The collection of over 80 international case studies developed within the International Energy Agency’s EBC Annex 57 research programme is used as the quantitative foundation to present a comprehensive analysis of the multiple interacting methodological parameters. The analysis of methodological parameters is structured by the stepwise methodological choices made in the building EEG assessment practice. Each of six assessment process steps involves one or more methodological choices relevant to the EEG results, and the combination potentials between these many parameters signifies a multitude of ways in which the outcome of EEG studies are affected.

The importance of embodied energy and embodied greenhouse gas emissions (EEG) from buildings is gaining increased interest within building sector initiatives and on a regulatory level. In spite of recent harmonisation efforts, reported results of EEG from building case studies display large variations in numerical results due to variations in the chosen indicators, data sources and both temporal and physical boundaries. The aim of this paper is to add value to existing EEG research knowledge by systematically explaining and analysing the methodological implications of the quantitative results obtained, thus providing a framework for reinterpretation and more effective comparison. The collection of over 80 international case studies developed within the International Energy Agency’s EBC Annex 57 research programme is used as the quantitative foundation to present a comprehensive analysis of the multiple interacting methodological parameters. The analysis of methodological parameters is structured by the stepwise methodological choices made in the building EEG assessment practice. Each of six assessment process steps involves one or more methodological choices relevant to the EEG results, and the combination potentials between these many parameters signifies a multitude of ways in which the outcome of EEG studies are affected.