Design strategies for low embodied energy and greenhouse gases in buildings: analyses of the IEA Annex 57 case studies

This paper introduces the IEA Annex 57 case study method, consisting of a format for describing individual case studies and an evaluation matrix covering all case studies. Sample case studies are used to illustrate the method and the evaluation matrix through a first preliminary analysis. In compiling and evaluation existing, transparent case studies we have taken a stakeholder perspective. By so doing it is intended to identify fordecision makers the key issues affecting EE/EC in buildings. Analysis in this paper focuses on one of the six case study themes, building design strategies for EE/EC mitigation and references cases covering e.g. material selection, building shape, construction stage strategies and strategies to handle the trade-off between embodied and operational impacts in net-zero emission building design

IEA EBC Annex 57 ‘Evaluation of Embodied Energy and CO_2eq for Building Construction'

The current regulations to reduce energy consumption and greenhouse gas emissions (GHG) from buildings have focused on operational energy consumption. Thus legislation excludes measurement and reduction of the embodied energy and embodied GHG emissions over the building life cycle. Embodied impacts are a significant and growing proportion and it is increasingly recognized that the focus on reducing operational energy consumption needs to be accompanied by a parallel focus on reducing embodied impacts. Over the last six years the Annex 57 has addressed this issue, with researchers from 15 countries working together to develop a detailed understanding of the multiple calculation methods and the interpretation of their results. Based on an analysis of 80 case studies, Annex 57 showed various inconsistencies in current methodological approaches, which inhibit comparisons of results and difficult development of robust reduction strategies. Reinterpreting the studies through an understanding of the methodological differences enabled the cases to be used to demonstrate a number of important strategies for the reduction of embodied impacts. Annex 57 has also produced clear recommendations for uniform definitions and templates which improve the description of system boundaries, completeness of inventory and quality of data, and consequently the transparency of embodied impact assessments

IEA EBC Annex 72 - Assessing life cycle related environmental impacts caused by buildings - Targets and tasks

Investment decisions for buildings made today largely determine their environmental impacts over many future decades due to their long lifetimes. Such decisions involve a trade-off between additional investments today and potential savings during use and at end of life - in terms of economic costs, primary energy consumption, greenhouse gas emissions and other environmental impacts. Life cycle assessment (LCA) is suited to identify measures and action to increase the resource efficiency and the environmental performance of buildings and construction. This paper gives an overview of an ongoing international research project within the IEA EBC with the overall aim to harmonise LCA approaches on buildings and foster life cycle thinking in the real estate and construction sectors. The objectives of the project are i) to establish a common methodology guideline to assess the life cycle based environmental impacts caused by buildings, ii) to establish methods for the development of specific environmental benchmarks for different types of buildings, iii) to derive regionally differentiated guidelines and tools for the use of LCA in building design and tools such as BIM, and iv) to improve data availability by developing national or regional databases with regionally differentiated LCA data tailored to the construction sector. To ensure practical solutions a number of case studies will be used to test and illustrate the consensus approaches and research issues

Embodied GHG emissions of buildings - Critical reflection of benchmark comparison and in-depth analysis of drivers

In the face of the unfolding climate crisis, the role and importance of reducing Greenhouse gas (GHG) emissions from the building sector is increasing. This study investigates the global trends of GHG emissions occurring across the life cycle of buildings by systematically compiling life cycle assessment (LCA) studies and analysing more than 650 building cases. Based on the data extracted from these LCA studies, the influence of features related to LCA methodology and building design is analysed. Results show that embodied GHG emissions, which mainly arise from manufacturing and processing of building materials, are dominating life cycle emissions of new, advanced buildings. Analysis of GHG emissions at the time of occurrence, shows the upfront \u27carbon spike\u27 and emphasises the need to address and reduce the GHG \u27investment\u27 for new buildings. Comparing the results with existing life cycle-related benchmarks, we find only a small number of cases meeting the benchmark. Critically reflecting on the benchmark comparison, an in-depth analysis reveals different reasons for cases achieving the benchmark. While one would expect that different building design strategies and material choices lead to high or low embodied GHG emissions, the results mainly correlate with decisions related to LCA methodology, i.e. the scope of the assessments. The results emphasize the strong need for transparency in the reporting of LCA studies as well as need for consistency when applying environmental benchmarks. Furthermore, the paper opens up the discussion on the potential of utilizing big data and machine learning for analysis and prediction of environmental performance of buildings

EZH2-mediated epigenetic repression of DNA repair in promoting breast tumor initiating cells

Members of the Polycomb-group (PcG) family of proteins, including EZH2 (enhancer of zeste homolog 2), are involved in establishing epigenetic silencing of developmental genes in adult and embryonic stem cells, and their deregulation has been implicated in cancer. In a recent report, EZH2-mediated epigenetic repression of DNA damage repair in breast tumor initiating cells (BTICs) was identified as a mechanism that could promote expansion of BTICs, and may contribute to cancer progression