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The purpose of this report is to illustrate the contribution of the International Energy Agency - Energy in Buildings and Communities (IEA EBC) Programme Annex 72 members to the topic of life-cycle multi-objective optimization of buildings performance. In detail, the purpose of the report is: To collect existing case studies developed by the Annex 72 members on optimization techniques applied for finding an environmental-energy-economic “optimum” among different design or retrofitting solutions; To examine the collected case studies and compare methodologies, applications and results, and deriving some general conclusions on the topic. The case studies are intended to be used as a basic knowledge for identifying: Optimization techniques to be used for finding the “optimum” among different alternative solutions; Solutions to be adopted for reducing both the energy consumption during the operation and the environmental impacts and costs during the whole life cycle and for avoiding that the benefits of a low energy building during operation are offset by the higher impacts due to additional materials/costs and energy required during the other life-cycle stages. The target groups of this report are scientists and developers and providers of building design tools.

The purpose of this report is to provide support to the design decisions-makers during the design process. For each of the defined design step decision the important topics to consider were identified, the key stakeholders are declared and the purpose of LCA at the selected design step is defined. The report covers: The definition of the design steps, the definition of the tasks in each design step and an overview of the relevant milestones for performing LCA; An overview of the systematic building decomposition methods and the appropriate levels at each design step; An overview of the tools that can be used for LCA and a selection process for choosing the right LCA tool. A special emphasize is given to the topic of Building Information Modelling (BIM), how the BIM tools can facilitate the LCA assessment and what information should be implemented in the BIM model; Strategies on how to reduce the design-related uncertainties; An overview of the visualization of the LCA results and which are appropriate in the selected design steps.

This report focuses on methodological issues related to the determination, assessment and presentation of the environmental performance of buildings. The purpose of this report is to provide the foundations to responsible parties for further developing their specific methods to assess the primary energy demand, GHG emissions and further environmental impacts of buildings and to increase the mainstreaming of practice globally. As far as possible, this should lead to a standardization of methods used worldwide. Where this goal cannot be achieved, methodological differences can be at least identified. The specific objectives of this report are to: clarify methodological questions that have been shown as significant but are under-addressed in the analysis of methods currently in use in the Annex 72 participating countries provide a consistent and transparent basis for a methodology and reporting structure for environmental performance assessment in line with international standards to enable comparability and usability of results contribute to the interpretation and supplementation of international standards to improve their applicability and support their dissemination promote long-term and life cycle-based thinking, by encouraging the early consideration of likely future environmental impacts regarding maintenance, repair and replacement as well as of durability and adaptability of building components and the building as a whole contribute to the overall efforts of national governments and standard makers to guide construction and real estate industry on how to respond to climate change promote the application of principles for circular economy by encouraging the early consideration of the deconstructability of buildings and building components and quantification of their reuse, recycling and/or recovery potential enable benchmarking and target-setting.

Buildings are one of the most significant energy consumers and carbon emitters. As a result, their energy efficiency is a focal subject of European legislation, including the regulation of nearly zero energy building (NZEB) constructions. NZEB definition, however, differs significantly when it comes to the national level. Consequently, residential NZEBs can be characterised with altering building physical characteristics and various energy demands, according to the location of the buildings. More than that, not only the construction, but also heating, ventilation and air conditioning (HVAC) systems can be highly dependent on the geographic, especially weather conditions. With the help of dynamic building energy performance simulation (BEPS), this study reveals how the location of a single-family house affects the operational energy consumption of heating and cooling, once from the perspective of the different national NZEB regulations and also as a result of diverse climatic conditions influencing the performance of the technical building system. For the latter, we focus on one of the most expanding heat supply solution, the air-source heat pumps. To adequately address the reduction of the environmental impacts of the building sector, besides energy consumption the study analyses operational carbon emissions as well. Results highlight that though there are differences in the requirements of the specific NZEBs, some remain to produce similar indicators in all aspects, while other Member States (MS) are appealing from certain indicators, yet much worse in carbon emission. Conclusions of the paper can be considered to improve operational energy or emission management through the legislation of the building stock, MS specifically., CLIMA 2022 conference, 2022: CLIMA 2022 The 14th REHVA HVAC World Congress

QC 20120126 ENSLIC BUILDING : Energy Saving through Promotion of Life Cycle Assessment in Buildings

QC 20120210 ENSLIC_BUILDING : Energy Saving through Promotion of Life Cycle Assessment in Buildings

The IEA EBC Annex 72 focuses on the assessment of the primary energy demand, greenhouse gas emissions and environmental impacts of buildings during production, construction, use (including repair and replacement) and end of life (dismantling), i.e. during the entire life cycle of buildings. In one of its activities, reference buildings (size, materialisation, operational energy demand, etc.) were defined on which the existing national assessment methods are applied using national (if available) databases and (national/regional) approaches. The "be2226" office building in Lustenau, Austria was selected as one of the reference buildings. TU Graz established a BIM model and quantified the amount of building elements as well as construction materials required and the operational energy demand. The building assessment was carried out using the same material and energy demand but applying the LCA approach used in the different countries represented by the participating Annex experts. The results of these assessments are compared in view of identifying major discrepancies. Preliminary findings show that the greenhouse gas emissions per kg of building material differ up to a factor of two and more. Major differences in the building assessments are observed in the transports to the construction site (imports) and the construction activities as well as in the greenhouse gas emissions of the operational energy demand (electricity). The experts document their practical difficulties and how they overcame them. The results of this activity are used to better target harmonisation efforts., Proceedings of the 2019 Sustainable Built Environment Conference (SBE19)