1. The challenge of integrating Life Cycle Assessment in the building design process - a systematic literature review of BIM-LCA workflowsTajda Potrč Obrecht, Martin Röck, Endrit Hoxha, Alexander Passer, 2019, published scientific conference contribution Abstract: To foster sustainable development in construction sectors, environmental impacts need to be reduced dramatically. The Life Cycle Assessment (LCA) technique is the most firmly established methodology used to quantify these environmental impacts and, therefore, has been applied with increasing frequency to assess the environmental performance of buildings. To effectively improve a building's environmental performance, an integration of LCA in the design process is required. This can be achieved by coupling LCA with digital design tools, e.g., Building Information Modelling (BIM). To identify the pro and cons of streamlining the integration of LCA and BIM, a comprehensive Systematic Literature Review (SLR) was performed. We identified more than 50 relevant BIM-LCA case studies and analysed the applied BIM-LCA workflows in detail. In most of the studies reviewed, the LCA has been applied in an early design stage. The authors primarily used LCA tools and manual or semi-automatic methods to exchange data between BIM models. In most cases, contemporary BIM-LCA workflows utilized conventional spreadsheets (e.g., Excel worksheets). However, the results of the analysis show that an automated link between LCA and BIM can be achieved if certain challenges are overcome. By automating exchange of information between BIM and LCA tools and improving the reliability of this process, the LCA application can be streamlined in design practice and, hence, the necessary improvements of the environmental performance of buildings can be supported. Keywords: building information modelling, life cycle assessment, systematic Literature Review Published in DiRROS: 18.03.2024; Views: 341; Downloads: 206
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2. BIM and LCA integration : a systematic literature reviewTajda Potrč Obrecht, Martin Röck, Endrit Hoxha, Alexander Passer, 2020, review article Abstract: To foster sustainable development, the environmental impacts of the construction sector need to be reduced substantially. Life cycle assessment (LCA) is the established methodology for the quantification of environmental impacts, and therefore has been increasingly applied to assess the environmental performance of buildings. By coupling LCAs with digital design tools, e.g., building information modeling (BIM), the identification of environmental hotspots and their mitigation is possible during the design process. The objective of the study is to identify the current integration approaches, and determine the pros and cons of the integration process from different viewpoints, namely, technical, informational, organizational and functional issues. Therefore, a comprehensive systematic literature review (SLR) was performed. We identified 60 relevant BIM-LCA case studies and analyzed the applied BIM-LCA workflows in detail. A total of 16 of the reviewed studies applied LCA during the early design stage. These studies used a manual or semiautomatic data exchange between the BIM models and LCA tools. In most cases, contemporary BIM-LCA workflows utilized conventional spreadsheets (e.g., Excel sheets in 16 cases). However, the analysis shows that an automated link between LCA and BIM can be achieved when overcoming the technical, organizational and informational issues discussed in the paper. This could enable the streamlining of LCA applications in design practice, and thus support the necessary improvements in the environmental performance of buildings. Keywords: building information modeling (BIM), life cycle assessment (LCA), systematic literaturereview (SLR), environmental product declarations (EPD), workflow, bill of quantities (BoQ) Published in DiRROS: 05.03.2024; Views: 484; Downloads: 152
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3. Development of an advanced methodology for assessing the environmental impacts of refurbishmentsTajda Potrč Obrecht, Sabina Jordan, Andraž Legat, Marcella Ruschi Mendes Saade, Alexander Passer, 2022, published scientific conference contribution Abstract: The refurbishment of the building stock is one of the key tasks for reducing the future environmental emissions in building sector. The assessment of the environmental impacts (EI) of refurbishments with LCA methodology remains a challenge. In the current practice, the refurbishment is threated as the beginning of the new lifecycle and all the impacts associated with the previous life cycle are generally neglected. The exclusion of materials and components used prior to the refurbishment produces a data gap at the end-of-life since information about materials that remained in the building after the refurbishment are missing. Furthermore, no information about what impacts have already been considered in the past bears the risk that some of the impacts are double-counted. In order to overcome these problems, an advanced methodology for the assessment of the embodied impacts in the case of refurbishment was developed that combines two sub-methodologies that can also be used separately. The first submethodology is used for remodelling the input data in order to make them time corresponding. The second sub-methodology is used for the assessment of the EI in the residual value of building materials and components and is including the allocation of EI between the life cycle before and after the refurbishment. The combination of the two sub-methodologies enables a more realistic and accurate assessment of the environmental impacts. The methodology is illustrated on the case on the case of a façade refurbishment. Five different allocation approaches are investigated and the residual value is calculated after a selected time period before and after the refurbishment. For all the inputs time-corresponding data is modelled and used. The study showed that for the life cycle before the refurbishment the EI and the residual value are generally higher if time-corresponding data is used since the EI of the electricity mix are higher. It turned out that the use of different allocation approaches is favouring either the use of recycled or reused materials or the recycling of the materials at the end. The PEF and the cut-off approach with module D are both enhancing the circular economy. It can be assumed that they are likely to prevail in the future. Keywords: LCA, refurbishment, allocation, module D, dynamic LCA Published in DiRROS: 31.01.2024; Views: 367; Downloads: 194
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4. The role of electricity mix and production efficiency improvements on greenhouse gas (GHG) emissions of building components and future refurbishment measuresTajda Potrč Obrecht, Sabina Jordan, Andraž Legat, Alexander Passer, 2021, original scientific article Abstract: Purpose: An estimation of the environmental impact of buildings by means of a life cycle assessment (LCA) raises uncertainty related to the parameters that are subject to major changes over longer time spans. The main aim of the present study is to evaluate the influence of modifications in the electricity mix and the production efficiency in the chosen reference year on the embodied impacts (i.e., greenhouse gas (GHG) emissions) of building materials and components and the possible impact of this on future refurbishment measures.
Methods: A new LCA methodological approach was developed and implemented that can have a significant impact on the way in which existing buildings are assessed at the end of their service lives. The electricity mixes of different reference years were collected and assessed, and the main datasets and sub-datasets were modified according to the predefined substitution criteria. The influence of the electricity-mix modification and production efficiency were illustrated on a selected existing reference building, built in 1970. The relative contribution of the electricity mix to the embodied impact of the production phase was calculated for four different electricity mixes, with this comprising the electricity mix from 1970, the current electricity mix and two possible future electricity-mix scenarios for 2050. The residual value of the building was also estimated.
Results and discussion: In the case presented, the relative share of the electricity mix GHG emission towards the total value was as high as 20% for separate building components. If this electricity mix is replaced with an electricity mix having greater environmental emissions, the relative contribution of the electricity mix to the total emissions can be even higher. When, by contrast, the modified electricity mix is almost decarbonized, the relative contribution to the total emissions may well be reduced to a point where it becomes negligible. The modification of the electricity mix can also influence the residual value of a building. In the observed case, the differences due to different electricity mixes were in the range of 10%.
Conclusions: It was found that those parameters that are subject to a major change during the reference service period of the building should be treated dynamically in order to obtain reliable results. Future research is foreseen to provide additional knowledge concerning the influence of dynamic parameters on both the use phase and the end-of-life phase of buildings, and these findings will also be important when planning future refurbishment measures. Keywords: global warming potential (GWP), production phase, electricity mix, production efciency, residual value, refurbishment, building components, life cycle assessment (LCA) Published in DiRROS: 31.07.2023; Views: 583; Downloads: 303
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5. An LCA methodolody for assessing the environmental impacts of building components before and after refurbishmentTajda Potrč Obrecht, Sabina Jordan, Andraž Legat, Marcella Ruschi Mendes Saade, Alexander Passer, 2021, original scientific article Abstract: Refurbishment is one of the most important measures for reducing the environmental impacts of the construction sector in the near future. According to the life cycle assessment (LCA) methodology for buildings, the environmental impacts of refurbishment measures should be assessed within the whole life cycle of the building and reflected in separate modules. However, in practice, refurbishment is often treated as the beginning of a new building life cycle. This leads to difficulties in correctly assessing the environmental impacts for the components that are reused or recycled after the refurbishment. The division of a building’s life cycle into two separate life cycles indicates that the environmental impacts must be divided between the life cycle before and the life cycle after the refurbishment for a correct assessment of the environmental impacts and a calculation of the residual value. We propose a newly developed methodology for calculating the environmental impacts and the residual value of refurbishment measures that also involves a division between life cycles. The new methodology is a combi-nation of already exiting methodologies that are innovatively combined and consists of four sequential steps. In the first step, the input, output and reuse flows between the life cycles before and after the refurbishment are defined. In the second step, the environmental impacts are assessed using the chosen allocation approach (i.e., the cut-off, cut-off with module D, avoided-burden, 50:50 and the product environmental footprint (PEF)). In the third step, a maintenance scenario is implemented according to the selected reference-service-life (RSL) database. In the fourth step, the residual value is estimated. The methodology was tested on selected building components. A sensitivity analysis for different allocation approaches and RSL databases was performed to show how the choice of these parameters can influence the results. The differences between the selected allocation approaches emerge if materials with recycled content are used or if the materials are being recycled or reused at the end of their life cycle. The developed methodology reliably estimates the environmental impacts as well as the residual value of the life cycle before and after the refurbishment. We expect that this research will stimulate practitioners to avoid the negligence of previous environmental flows, bringing scientific consistency to future assessments of refurbishment measures. Keywords: Life cycle assessment (LCA), refurbishment, allocation approaches, residual value, reference service life (RSL) Published in DiRROS: 28.07.2023; Views: 537; Downloads: 352
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