Net zero emission buildings: next generation of benchmarks and calculation rules

The definition of ambitious life cycle-based benchmarks and target values to limit the GHG emissions of buildings is seen as one of the most important steps in pushing the construction and real estate sector in significantly reducing its contribution to global warming. Especially target values are no longer only developed from a bottom-up perspective. There is now an interest by governments and sustainability assessment system providers in supplementing bottom-up approaches with science-based top-down approaches as part of their responsibility to respect planetary boundaries. The creation of GHG emission budgets in combination with target values, as well as the introduction of strict enough legal binding requirements already today is critical for achieving a climate-neutral building stock. Achieving these tasks requires tackling still open methodological issues. Following the work of IEA EBC Annex 72 and current developments in Germany, the paper presents main questions, key steps, modelling aspects that can cause variation and uncertainties, as well as clarifies key terms and definitions. It is highlighted that although a net zero emission requirement is a universal benchmark, information on system boundaries and calculation rules are still necessary to provide evidence of its fulfilment

Crafting local climate action plans: An action prioritisation framework using multi-criteria decision analysis

The COP21 target to keep global warming to well below 2 (or 1.5) degrees Celsius cannot be met without massive transformation in cities. A major challenge on the road to nearly greenhouse gas (GHG) emissions-neutral cities is the successful development of a climate action plan (CAP) by the local authority, sometimes within the framework of its participation to different initiatives (e.g. the Global Covenant of Mayors). While the identification of the best actions for reaching their long-term GHG emission reduction target constitutes a common decision-making problem for local authorities, it is also an intricate one: conflicting and incommensurable aspects such as environmental, economic, social and technical issues, as well as conflicting stakeholder interests should be dealt with simultaneously when actions have to be programmed. Multi-Criteria Decision Analysis (MCDA) methods are well-known to cope with these complexities and have already been used for decades in several fields. However, they have not been systematically used within the context of local CAPs. The methodologies which are normally implemented to support the prioritisation of actions wholly or to a great extent rely on economic analyses and do not capture the potential co-impacts. In this context, this paper proposes a general participatory framework for guiding collaborative prioritisation of actions as a methodology to help local authorities with the development of more sustainable CAPs, while using MCDA. Finally, advantages, limitations and further steps in research regarding the proposed framework are discussed

Analysis of new modules in connection with calculation of the climate impact of buildings

Currently, the lifecycle scope included in the building regulation covers the product stage (A1-3), the replacements (B4) and parts of the end-of-life stage (C3-4) of buildings. The Danish Social And Housing Authority has asked BUILD to investigate the climate consequences of, and possibilities for including new stages and modules in the future requirement for climate impact of buildings. In this report, this has been seen in relation to the expected climate effect, availability of data and workload associated with the calculation of the modules that have been omitted in the 2023 requirement. The report finds that the inclusion of transport of materials and products to construction site (A4), construction process (A5), refrigerant leakage in use stage (B1), maintenance (B2), deconsrtuction and demolition (C1) and tranpost to waste processing and disposal (C4) can increase the median climate impact result by 2.77 kgCO2eq/m2/year in a 50-year reference study period. This corresponds to 24% of the whole life cycle impact

On the definition and prioritization of strategies and actions to minimize greenhouse gas emissions in cities: An actor-oriented approach

Cities as hotspots of human economic activity and infrastructures provide some of the best opportunities for decarbonizing sectors essential for limiting the global warming to 1.5, such as buildings and transport. For this reason, regulators and researchers have widely recognized the necessity to put cities, as an important object of assessment, and city authorities, as an important actor group, at the core of climate mitigation efforts. In their pursuit of a low-emission future, however, cities are confronted with a number of theoretical and practical questions regarding allocation and accounting of city-related greenhouse gas (GHG), target setting and subsequent planning for mitigation. A wide literature is currently focused on the first two. However, to achieve ambitious climate targets, research should urgently focus more on how to reap all available urban mitigation actions and encourage rapid and radical changes. Identifying and prioritising mitigation strategies and actions to achieve the targets, as well as putting them together into a coherent plan with a clear vision of the future, are critical steps in actionable and effective climate action planning. As a first contribution in this direction, this paper provides recommendations for research and practice to support a more integrated and conscious definition and prioritization of actions by municipal stakeholders, based on: (1) the specific context of each city type as a determinant of what actions may work, (2) the executive power of city authority to act as the main actor and (3) the multiple benefits and/or trade-offs accruing from each local climate action

The level of knowledge, use and acceptance of LCA among designers in Germany: A contribution to IEA EBC Annex 72

Architects and engineers have become more concerned about the environmental consequences of their design solutions. Knowledge about Life Cycle Assessment (LCA) is crucial for the necessary building sector decarbonisation, as well as for mitigating other negative environmental impacts. In Germany, designers\u27 attitudes towards LCA have not been analysed since 2005. However, since then, certain developments – such as the establishment of the sustainability assessment systems BNB and DGNB – have taken place. In 2019, as part of the project IEA EBC Annex 72, a survey was conducted amongst designers in Germany. The paper presents the current status to identify the progress being made since 2005 and provides recommendations to overcome barriers to LCA dissemination. The results show that although German designers are currently doing a lot with regard to environmental performance assessment, the most critical aspects are considered in a more qualitative way, except for the mandatory operational energy performance calculations. LCA-know-how and application still lags behind expectation. To support an increased use of LCA during building design, not only the provision of related data and design/assessment tools is necessary, but also the establishment of standards and regulations. The latter will drive the also necessary client demand

Harmonised Carbon Limit Values for Buildings in Nordic Countries:Analysis of the Different Regulatory Needs

This report is a part of the Nordic Sustainable Construction programmeinitiated by the Nordic Ministers of Construction and Housing and funded byNordic Innovation. The programme contributes to the Nordic Vision 2030 bysupporting the Nordics in becoming the leading region in sustainable andcompetitive construction and housing with minimised environmental andclimate impact.The programme supports the green transition of the Nordic constructionsector by creating and sharing new knowledge, initiating debates in the sector,creating networks, workshops and best practice cases, and facilitating Nordicharmonisation of regulation for the climate impact of buildings.This report is one of the deliverables for Work Package 1 led by the FinnishMinistry of Environment.The work has been carried out by BUILD, SWECO and EFLA

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

Principles and Tools for Designing Strategies for Sustainable Urban Development: A “Process-based” and “Action-oriented” Approach at Neighbourhood Level

Cities constitute essential parts of the solution to many of the current sustainable development challenges. They have a major role to play in sustainable development both as crucial “engines” of socio-economic growth and significant “originators” of environmental loads. The special significance of cities for sustainable development is also reflected in the Sustainable Development Goal (SDG) 11 “Make cities and human settlements inclusive, safe, resilient and sustainable” of the 2030 Agenda for Sustainable Development. To organize and to support a sustainable urban development is, however, a particularly complex task to accomplish for any local authority or stakeholder group. The reasons for this complexity are related to the amplitude of the sustainability concept, to the variety and changing nature of the factors to be taken into account, as well as to the challenge for balancing the needs and interests of different stakeholder groups involved in – or affected by – urban interventions. The neighbourhood, as a more manageable urban unit than the city, and as a promising level to test out new ideas and ways of achieving sustainable urban development, has increasingly been acknowledged by research, policy and industry. The thesis therefore investigates new approaches to support sustainable urban development at the neighbourhood scale, with a specific focus on the neighbourhoods in Europe. Existing literature indicates that prevailing approaches are traditionally prescriptive and outcomes-based and fail to acknowledge the process nature of sustainable urban development. Furthermore, their contribution commonly starts and ends with the measurement of indicators and the provision of assessment results in the form of static “snap-shots” without those being reflected in specific possibilities for action in the local area. This hardly solves the problem of the (further) development of existing neighbourhoods. Decoding these results into context-specific strategies and actions, as well as ways of managing these actions, remains a challenge and an area not much researched yet. To remediate these weaknesses and gaps, the thesis proposes a comprehensive and integrated conceptual “process-based” and “action-oriented” overall framework which combines three approaches: (1) a step-by-step structured workflow model that decomposes the process of SUD into manageable tasks and incorporates all necessary quality requirements that should accompany a transition to sustainability; the purpose is to support the preparation phase of sustainable urban development process; (2) a methodology for identifying problem areas, their respective tradeoffs, as well as selecting, organising and describing indicators in an action-oriented fashion; the purpose is to provide a new proposal for linking indicators to possibilities for action so that their use does not only focus on assessing but also guiding development; (3) a methodology for prioritising and selecting concrete strategies and actions for neighbourhoods. The usefulness of the latter is illustrated by the means of a hypothetical case, and with the help of a web-based tool built by the author specifically for the multi-criteria decision analysis (MCDA) method ELECTRE III. The originality of this research lies in that such a comprehensive framework, bringing all the above-mentioned elements together into one coherent solution, has not been available until now. The value of the research is that the proposed overall framework can be a helpful decision support tool for any neighbourhood in Europe which is developing a sustainable development plan

Carbon Emissions during the Building Construction Phase: A Comprehensive Case Study of Construction Sites in Denmark

Buildings are major contributors of carbon emissions and related global warming. Emissions occur along all building stages, from a whole-life perspective, including material production, construction processes, building operations, maintenance and end-of-life processes. Upfront emissions include processes before building operations. They can be influenced immediately and will have a positive effect today. However, mitigation potentials during the construction stage are often overseen in research. This study presents an analysis of the carbon emissions of 61 Danish construction sites based on their energy consumption, waste production (module A5) and transport to site (A4). The results show carbon emissions for A4 of 0.28 and for A5 of 1.00 kgCO2e/m2 gross floor area per year over 50 years. This is 13.47% of the Danish whole-life carbon reference of 9.50 kgCO2e/m2y, which includes the product stage (A1–3), replacements (B4), operational energy use (B6) and waste processes and disposal (C3–4). Almost half of the emissions are related to construction waste followed by electricity, heat and fuel. Floor area and building use have not shown to be influential for carbon emissions, suggesting other parameters are more important. The significance of modules A4 and A5 suggests implementing them in future whole-life carbon assessments and related policies. This paper also demonstrates the development of generic emission coefficients, which are suited to increase the feasibility for application in the building industry. Finally, the usability of module A4 and A5 in environmental product declarations is discussed