Youssef ALMEZERAANI MAKING LIFE CYCLE ASSESSMENT OF BUILDINGS A PART OF EVERYDAY BUILDING DESIGN THROUGH BIM- BASED INTEGRATION

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1 Univerza v Ljubljani Fakulteta za gradbeništvo in geodezijo Youssef ALMEZERAANI MAKING LIFE CYCLE ASSESSMENT OF BUILDINGS A PART OF EVERYDAY BUILDING DESIGN THROUGH BIM- BASED INTEGRATION VKLJUČEVANJE OCENE ŽIVLJENJSKEGA CIKLA STAVB V NAČRTOVALSKI PROCES S POMOČJO INTEGRACIJE BIM Master thesis No.: Supervisor: Cosupervisor: Assist. Prof. Mitja Košir, PhD Assist. David Božiček Ljubljana, 2021

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4 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. IV BIBLIOGRAFSKO DOKUMENTACIJSKA STRAN IN IZVLEČEK UDK: : :004(043.3) Avtor: Mentor: Somentor: Naslov: Tip dokumenta: Obseg in oprema: Youssef Almezeraani doc. dr. Mitja Košir asist. David Božiček Vključevanje ocene življenjskega cikla stavb v načrtovalski proces s pomočjo integracije BIM Magistrska delo 61 str., 33 slik, 9 pregl. Ključne besede: ocena življenjskega cikla (LCA), modeliranje gradbenih informacij (BIM), trajnost, podatki, oblikovanje Izvleček: Metoda ocenjevanja življenjskega cikla (LCA) omogoča izračun okoljskega vpliva stavb v njihovi življenjski dobi, in je tako eno izmed ključnih orodij za vrednotenje trajnosti v gradbenem sektorju. V nalogi obravnavamo LCA iz vidika uporabe v načrtovalski praksi preko integracije s konceptom informacijskega modeliranja stavb (BIM). Po obsežnem pregledu literature je bila razvita LCA-BIM integracijska metoda ter preizkušena na vzorcu načrtovalskih različic teoretične stavbe. Rezultati so pokazali, da je vključitev metode LCA v BIM nezapleteno modeliranje različnih variant stavbe, natančno zbiranje podatkov, jasno obdelavo in vizualizacijo rezultatov ter celovito primerjavo načrtovalskih različic na osnovi izbranih indikatorjev. Iz vidika načrtovalca stavbe, se izkaže, da je interpretacije LCA rezultatov lahko kompleksna, saj ni standardiziranih priporočil za vrednotenje okoljskih vplivov večje skupine načrtovalskih različic stavb. Uporaba različnih metod/ konceptov interpretacije LCA rezultatov, lahko načrtovalca vodi do različnih odločitev glede optimalne izbire zasnove stavbe. Dodatno smo preko uporabe zasnovane LCA-BIM integracijske metode na realnemu projektu poudarili, da je ključna vključitev LCA v zgodnjih načrtovalskih fazah. V nalogi smo ugotovili da je LCA-BIM integracija izvedljiva, kar smo prikazali z razvito metodo. Poleg tega lahko zaključimo, da potrebujejo načrtovalci stavb kadar primerjajo okoljski vpliv (rezultate LCA) različnih zasnov stavbe, standardiziran postopek, ki jim omogoči enostavne in robustne okoljske odločitve.

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6 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. VI BIBLIOGRAPHIC DOCUMENTALISTIC INFORMATION AND ABSTRACT UDC: : :004(043.3) Author: Supervisor: Cosupervisor: Title: Document type: Scope and tools: Youssef Almezeraani Assist. Prof. Mitja Košir, PhD Assist. David Božiček Making Life Cycle Assessment of Buildings a Part of Everyday Building Design Through BIM-based Integration Master thesis 61 p., 33 fig., 9 tbl. Keywords: Life cycle assessment (LCA), Building information modelling (BIM), Sustainability, Data, Design Abstract: The life cycle assessment (LCA) methodology is one of the most applied ways to evaluate the environmental impacts of buildings and is an important part for sustainability in the construction sector. This dissertation proposes an analytical process addressing the subject of making life cycle assessment of buildings a part of everyday building design through BIM-based methodologies. The focus was on LCA-BIM integration and LCA results interpretation in context of building design. After an expansive literature review, a methodology was developed and tested on theoretical case study involving multiple building design alternatives. The results showed that the integration of LCA analysis into BIM enabled a smooth compilation of multiple design alternatives, accurate data acquisition, clear processing of outcomes and a comprehensive comparison of design variants based on the set of environmental criteria. From a buildings designer point of view, the LCA results interpretation showed to be complex as there are no standardised guidelines on how to evaluate LCA results of multiple design alternatives. Study findings showed that building designer decisions can be influenced by the LCA interpretation method/ concept, which can lead to diverse design decisions. Additionally, through a real-life case study, we underlined that the LCA concepts should be included in early design stages. We conclude that the BIM- LCA integration is achievable, which we presented through the methodology developed in this dissertation, and that building designer should have standardised guidance when interpreting LCA results in order to simplify the decision-making process when evaluating multiple design alternatives.

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8 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. VIII ACKNOWLEDGEMENTS Throughout the research process of the thesis, I have received a great deal of support and assistance. First, I would like to thank my supervisor Dr. Mitja Košir and my cosupervisor Assist. David Božiček, whose expertise in the construction field generally and in the building life cycle assessment specifically was invaluable in the formulating of the research topic and the methodology in particular. I would like to acknowledge as well L+Partners architecture office in Milan, Italy lead by Arch. Roberto Lapi and the BIM manager Marco Bramini for providing me with an additional case study through an interesting collaboration and valuable guidance from the company. I would also like to thank BIM A+ staff, Consortium (Univerza v Ljubjani, Politecnico di Milano and Universidade do Minho) and colleagues for the excellent cooperation and for all the academic and cultural opportunities I was given during this enlightening educational path in challenging times. Finally, there are my family especially my parents along with Abbot Boulos Tannoury and Mr. Abdallah Tannoury whose support was fundamental for the realisation of the master, and my friends who were of great support in deliberating over my problems and findings, as well as providing happy distraction to rest my mind outside of my research.

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10 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. X TABLE OF CONTENTS ERRATA... II BIBLIOGRAFSKO DOKUMENTACIJSKA STRAN IN IZVLEČEK... IV BIBLIOGRAPHIC DOCUMENTALISTIC INFORMATION AND ABSTRACT... VI ACKNOWLEDGEMENTS... VIII TABLE OF CONTENTS... X INDEX OF FIGURES... XII INDEX OF TABLES... XIV LIST OF ACRONYMS AND ABBREVIATIONS... XV 1 INTRODUCTION LITERATURE REVIEW Life cycle assessment (LCA) General overview and application LCA at various levels Limitations of LCA for buildings LCA results interpretation approaches LEED v Soft comparative assertion method IBO method Summary LCA-BIM integration Building modelling information (BIM) Existing approaches of LCA-BIM integration LCA and project design stages LCA tools and databases METHODOLOGY Approach and overview Application Development and data flow... 18

11 XI Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration LCA-BIM integration framework Building and design alternatives Cost estimation Energy simulation LCA implementation through Oneclick LCA Data visualisation Results interpretation LCA-BIM integration method LCA results interpretation approaches RESULTS Proposed methodology s outcome Decision making with various LCA results interpretation methods LEED v4 interpretation outcome Soft comparative assertion interpretation outcome IBO interpretation outcome Evaluation of the approaches DISCUSSION Additional real-life case study Evaluation and considerations CONCLUSIONS REFERENCES APPENDICES APPENDIX A: Cost-estimation Revit schedules for design option Wood Double gl Cellulose APPENDIX B: Dynamo script as run on the design option Wood Double gl Cellulose.. 52 APPENDIX C: Parallel coordinate charts of the design options... 59

12 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. XII INDEX OF FIGURES Figure 1: Building life cycle stages (Nwodo & Anumba, 2019)... 3 Figure 2 Stages of an LCA according to EN ISO (EN, 2006)... 4 Figure 3 Scheme showing the LCA method applied on products, building elements, and building levels for environmental decisions Figure 4 Future impact and likelihood of technologies (Poljanšek, 2017)... 9 Figure 5 BIM data life cycle by BCG (Gerbert, et al., 2016) Figure 6 Level of development matched to the information availability (OneClickLCA) Figure 7 Design development stages overlapped from 3 various sources Figure 8 LCA flow possibilities across the model development stages Figure 9 Workflow of the proposed methodology Figure 10 Schematic view of the BIM model in Revit Figure 11 Design options as arranged inside the BIM model Figure 12 Operational energy simulations in Green Building Studio Figure 13 Annual energy simulation showing the EUI value for the option Wood - Double gl Cellulose Figure 14 Data extraction from the BIM model to OneClick LCA tool through the Revit plug-in Figure 15 Parameter section in the plug-in and grouping criteria in the online tool Figure 16 Parallel coordinates chart showing the results of the 13 design options Figure 17 Chart highlighting the best performing cheap option Bricks Triple gl Rockwool and the median value Figure 18 Chart highlighting the best performing most expensive option Wood Triple gl Cellulose and the median value Figure 19 Chart highlighting the worst performing cheapest option Bricks - Double gl Rockwool and the median value Figure 20 Soft comparative assertion method final categorisation with design options ordered from the bottom having the highest impact score to the top having the lowest impact score Figure 21 Impact scores of the Soft comparative assertion based on the egalitarian and footprint principles Figure 22 OI3 indicators calculated for the design options based on the IBO method Figure 23 Photos of the on-going construction taken on site by L+Partners team Figure 24 LCA results and cost for different flooring options Figure 25 Chart highlighting the option Wood Triple gl Rockwool and the median value Figure 26 Chart highlighting the option Bricks - Double gl EPS and the median value... 59

13 XIII Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Figure 27 Chart highlighting the option Bricks Double gl Cellulose and the median value Figure 28 Chart highlighting the option Wood Double gl EPS and the median value Figure 29 Chart highlighting the option Wood Double gl Rockwool and the median value Figure 30 Chart highlighting the option Wood Triple gl EPS and the median value Figure 31 Chart highlighting the option Bricks Triple gl Cellulose and the median value Figure 32 Chart highlighting the option Bricks Triple gl EPS and the median value Figure 33 Chart highlighting the option Wood Double gl Cellulose and the median value... 61

14 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. XIV INDEX OF TABLES Table 1 Comparison between the three BIM-LCA integration approaches Table 2 Comparison between the four LCA tools characteristics Table 3 Naming convention and combination for the proposed construction material Table 4 Grouping of the design options based on the median line Table 5 Ranking of the design options based on the impacts and the cost estimation Table 6 Improvement percentage calculated for 3 design options according to the LEED method.. 31 Table 7 Ranking comparison based on the LCA results of the proposed and existing approaches Table 8 Total quantities of the modelled finishing materials Table 9 Table showing the alternative options for the flooring... 37

15 XV Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. LIST OF ACRONYMS AND ABBREVIATIONS AECO AIA AP BCG BIM BNB BoQ BREEAM DGNB EN EP EPD GBCI GWP ISO LCA LCC LCIA LEED LOD NREL ODP POCP R SIP U Architecture Engineering Construction Operation American Institute of Architects Acidification potential Boston Consultancy Group Building Information Modelling The Assessment System for Sustainable Building in Germany Bill of quantities Building Research Establishment Environmental Assessment Method The German Sustainable Building Council European Norm Eutrophication potential Environmental product declaration Green Business Corporation Inc. Global warming potential International Organization for Standardization Life Cycle Assessment Life Cycle Costing Life Cycle Inventory Analysis Leadership in Energy and Environmental Design Level of Detail National Renewable Energy Laboratory Ozone depletion potential Formation of ozone of lower atmosphere Thermal resistance [(m 2 K)/W] Structural insulated panels Heat Transfer Coefficient [W/(m 2 K)]

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17 1 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 1 INTRODUCTION The construction and maintenance of buildings significantly influence the total amount of resources consumed and emissions released into the environment (Obrecht, et al., 2020). In continental Europe, the energy used in buildings alone consumes up to 40% of all raw materials extracted from the lithosphere and is responsible for roughly 50% of global greenhouse gas emissions. (Röck, et al., 2018). The life cycle assessment (LCA) is one of several environmental management techniques that addresses the environmental aspects and potential environmental impacts throughout a product s life cycle from raw material acquisition through production, use, end of life treatment, recycling, and final disposal (EN, 2006). The importance of conducting a building LCA analysis relies on getting the whole image of the impacts by shifting the focus from the operational energy, as the sole contributor for the environmental footprint of a building, to including it as a part of the contribution along with the embodied impacts of the whole building life cycle. However, the LCA analysis of systems is an abstract task. Its results are indefinite, making it hard to evaluate and visualise the impacts on the various environmental areas usually calculated over decades or even a century. Also, when dealing with the built environment, the specificity of each building makes it difficult to compare results even when standards and codes exist. With such a blurry global matter that could be barely concretised, many future capabilities of the LCA are questioned as the following: Will we be able to have one day benchmarks for the environmental impacts so we can evaluate the actual contribution of the optimised LCA analysis results? What is the role of BIM-based processes in contributing to and integrating with the LCA analysis? Will it be possible to standardise the LCA application processes globally so it can benefit optimally from the rising standardisation in the construction sector? Such obvious questions remain open-ended. The dissertation is an academic attempt developing a methodology to answer mainly the BIM-LCA integration possibilities. It investigates the different approaches of integrating LCA into the BIM workflow along with an overview of common LCA tools and their BIM capabilities. Analysed side by side to benchmarked estimations and simulations available in the digital environment, the aim is to influence most efficiently the design and the decision makers at an early design phase. The methodology s capabilities of BIM-LCA integration are tested mainly on a theoretical case study in an adequate framework as well as on a real-life project. Finally, the results interpretation dilemmas, that are still quite unclear in the construction industry, are also discussed to evaluate the potential of building designers to make environmental decisions based on LCA data.

18 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 2 2 LITERATURE REVIEW In order to answer the dissertation questions, relevant literature was identified based on two primary sources. Most importantly, the majority of the references related directly to the research topic were scientific papers sourced from Source Direct data base. Also, additional published works that showed a potential contribution to the research content were identified based on simple search criteria on the internet. Since most of the critical progress in the BIM-LCA integration happened recently, relevant content were mostly published in digital versions. Therefore, in addition to the universities library websites (the University of Ljubljana and Politecnico di Milano), a simple search using the keywords BIM / Building Information Modelling and/or LCA / Life Cycle Assessment and/or integration on the Google search engine led to numerous relevant references. Also, the snowball approach was applied by checking references cited in the papers identified as relevant to collect additional literature. Firstly, the review started by focusing on the life cycle assessment definition, identifying its different aspects. Then, it continued by reviewing the existing approaches of LCA integration in the BIM context, taking a more detailed look at what was considered until today. In addition, the research went beyond the literal meaning of the topic to pay attention to the various results interpretation methods of the LCA analysis. It is important to note that the mentioned sources led to these results after reading the published references partially or fully. Also, along with papers and articles, the search criteria included conference proceedings, master s and/or doctoral theses, websites, and webinars. 2.1 Life cycle assessment (LCA) The function of LCA is to compute and quantify the environmental impacts of products and services throughout their life cycle. Focusing on buildings, the relevant standards (EN & EN 15804) describe the life cycle stages through information modules A, B, C and D. Module A covers the product and construction process stage, module B the building use stage, module C the end-of-life stages and module D the potential benefits and loads after the finished building life cycle (e.g., energy utilisation of wooden building components). Each life cycle stage is split in submodules, describing the relevant life cycle stages in a buildings service life (Figure 1). It covers extraction of raw materials, manufacturing and transportation to the site, construction, operation, and maintenance, until end-of-life and recycling or demolition as defined by the standard EN (EN, 2011). As such, LCA is one of the most promising internationally applied techniques for ecological design (Dossche, et al., 2017).

19 3 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Figure 1: Building life cycle stages (Nwodo & Anumba, 2019) General overview and application The concepts that later became (environmental) LCA first emerged in the 1960s (Baumann & Tillman, 2004), when concerns over the limited availability of raw materials and energy resources led to new ways to account for energy use and the consequences of these uses (Bayer, et al., 2010). Until the early 1990s, studies that assessed the material, energy and waste flow of a product s life cycle were conducted under a variety of names including the resource and environmental profile analysis (REPA), Eco balance, integral environmental analyses and environmental profiles (Valdivia, et al., 2011). In the second half of the 1990s, the International Organization for Standardization (ISO) published the most important standards of LCA methodology: EN ISO Principles and framework, EN ISO Goal definition and inventory analysis, EN ISO Life-cycle impact assessment, and EN ISO Life-cycle interpretation (Najjar, et al., 2017). More specifically, as established in the EN ISO and standards, an LCA is carried out in four main phases, as shown in Figure 2, which are typically interdependent: 1. Goal and scope. 2. Inventory analysis. 3. Impact assessment. 4. Interpretation. Phase 1 (Goal and scope): The goal and scope contain explicit objectives and technical information defining the context of the assessment, including the actors and participants, functional unit, level of detail, system boundaries, assumptions, limitations, impact categories, methods, results and finally the communication of the results.

20 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 4 Phase 2 (Inventory analysis): All information and data about the life cycle of a product, material, or an assembly of them are carefully collected, analysed and approved in the life cycle inventory (LCI) analysis phase and are then grouped in the inventory as a reliable database of material and energy flows to proceed the LCA analysis. Phase 3 (Impact assessment): In this phase, the use of a life cycle impact assessment (LCIA) method translates the inventory analysis results into measurable environmental impacts. According to relevant standards for the built environment EN (EN, 2019) and EN (EN, 2011), the environmental impact for buildings is presented through various environmental impact indicators. Usually, six main environmental categories are considered: climate change, ozone depletion, photochemical ozone creation, acidification, eutrophication and depletion of abiotic resources. Additional indicators can be added, e.g., human and ecological toxicity. The problem areas are a subject of some controversy in discussions and have not all achieved international consensus (Kohler, et al., 2010). Optional steps such as normalisation, aggregation, and weighting could be added to proceed differently with the following phase. The assessment method, the environmental impacts, and the optional steps depend on decisions taken previously in phase 1. Phase 4 (Interpretation): The last phase consists of the results interpretation. To comply with EN ISO (2006) and EN ISO (2006), the interpretation must identify issues based on the results of LCI and LCIA, and evaluate the completeness, sensitivity, and consistency of the whole analysis. It must also guide to conclusions, limitations, and recommendations, and influence the project's decisionmaking. Finally, a critical review is also mandatory where results are made available to the public (Valdivia, et al., 2011). Figure 2 Stages of an LCA according to EN ISO (EN, 2006) LCA at various levels Standards exist for general LCA of products and services (EN ISO 14040, 14044, 14025), for building products (EN 15804) and for buildings as a whole (EN 15978). However, existing or new buildings are assemblies and combinations of several manufactured products and materials. Currently environmental product declarations (EPDs), which are documents for communicating LCA data, are becoming increasingly available (ConstructionLCA, 2018). Having more EPDs and databases of LCA results for

21 5 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. building products and services available, the most straightforward way for conducting an LCA analysis of a building is to use data of the various building subcomponents. The standardised environment for products is currently far more advanced than for the buildings. This is due to the life cycle duration difference and the typology of each, making the analysis for products far less complicated and more specific. Therefore, an important matter for building designers is to separate the LCA on a building product, building element and building level. Considering these facts, the LCA analysis for buildings follows the same application phases but with different objectives explained in Figure 3, being more adapted to the built environment specifics Limitations of LCA for buildings Since its introduction to the building sector, multiple LCA methodologies have been developed to reach more adequate results and objective interpretations. This advancement was due to the continuous increase in environmental research and discussions about the need for a more sustainable built environment through LCA. The iterative and experimental nature of the LCA process for guidance has made the application of various methodologies more comprehensive (Wittstock, et al., 2011). Also, recently, the market has witnessed a growing preparation by providing for the designers and contractors transparent open data sources about construction products and materials (EN, 2019). However, many aspects are still obstructing a wider spread of LCA into the building sector. Despite the aim of the LCA methodology to evaluate the concept of sustainability in the construction sector, different challenges are facing the application of LCA in this field (Najjar, et al., 2017). While the application process requires a substantial amount of precise and consistent data to obtain objective and accurate results, buildings on the other hand are assemblies of multiple materials and products that differ from one building to another. Therefore, due to the lack of consistency in data describing and analysing buildings, many uncertainties become evident in the analysis since individual buildings can be considered unique prototypes (there are exemptions, e.g., prefabricated modular buildings). In some cases, like in refurbishment and restoration projects, description of existing construction materials and products is totally lacking, resulting in an incomplete analysis because of the unavailability of data. In recent years, the availability of LCA data for building products are making the whole building LCA easier to conduct by designers. The increasing awareness of the general public, the industry and the governments has raised the concept of integrating LCA into management systems and using it in environmental policymaking, because LCA can assist in communicating environmental issues in a balanced way. LCA is also increasingly accepted as a technique by organisations to inform strategic decision-making (Valdivia, et al., 2011). For example, it has been introduced in some green certification programs in order to improve accreditation, e.g. LEED (GBCI), BREEAM (BREEAM), DGNB (DGNB). However, LCA for buildings is still not mandatory or enforced by legislation. Also, despite the obvious importance of the LCA analysis, the optimised results and impacts can be difficult to

22 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 6 quantify and evaluate. Due to the exposed limitations, substantial efforts are needed to improve the process to become applicable in building design (Kohler, et al., 2010). ` Goal and scope System boundary or Life cycle stages (e.g., cradle to gate), declared unit, cut-off criteria, LCIA categories to be covered (e.g., Global warming) LCA building product level (EN ISO 14025, EN 15804) Inventory analysis Principles and method approach regarding input data (which data to collect and how to allocate data between products) Output: Elementary flows (emissions, resources, energy) Interpretation Conclusions, limitations, recommendations, decisionmaking (Identification of issues based on the results of LCA and LCIA, evaluation that considers completeness, sensitivity, and consistency checks) Impact assessment 1. Selection of impact categories, category indicators and characterisation models 2. Assignment of LCI results to the selected categories - classification 3. Calculation of category indicator results characterisation Different LCIA options: (i) Midpoint (multiple environmental categories focusing on specific mechanisms, e.g., global warming potential, eutrophication potential = results in EPDs) (ii) Endpoint (human health protections, resource conservation, single score indicators, e.g., monetary value of the impact) Goal and scope System boundary or Life cycle stages Functional unit (whole building, building element, which life cycle stages included, environmental categories) LCA buildings, building elements (EN 15978) Inventory analysis Input: LCA data (EPDs, LCA databases) Bill of materials, Energy demand, Water usage, Transportation, Construction, End of life scenarios Impact assessment DATA consistency and plausibility: Mapping of LCA data of different materials, Quantity of materials LCA results and environmental categories Interpretation If analysing a SINGLE DESIGN: Identifying environmental hotspots -> information for environmental optimisation If analysing MULTIPLE DESIGN ALTERNATIVES: Comparison of LCA results, identifying environmental superiority or inferiority. In modern digitalised building design (BIM), it is possible to quickly generate various design alternatives Environmental decisions After using LCA data on the building level, we can make environmental decisions in the scope of the observed system (functional unit, life cycle stages, environmental categories) Figure 3 Scheme showing the LCA method applied on products, building elements and building levels for environmental decisions.

23 7 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration LCA results interpretation approaches Over the years, holistic environmental assessment of buildings, building components and building materials has gained significant importance (Singh, 2017). In the interpretation of a life cycle assessment, EN ISO requires the results of the inventory and the impact assessment to be evaluated with the aim of deriving conclusions and providing recommendations (Kohler, et al., 2010). In the case of buildings, the results depend on the considered scenarios. Furthermore, when analysing environmental impacts at an early design stage, the results substantially depend on data availability and accuracy, resulting in a high level of uncertainty. Therefore, comes the following important question: Are the results of the calculation of two building variants significant, i.e. does, for instance, a difference in the overall balance of 5% of the global warming potential mean that one variant is better than the other, or does the reason for the difference lie in the inaccuracy of the base data, hypotheses or simplifications of the calculations (Kohler, et al., 2010)? In modern digitalised building design, various alternatives can be compared. With multiple environmental categories, it can be difficult to evaluate the LCA results and choose the alternative which has the lowest environmental impact. It is true that no standardised method for results interpretation of various design alternatives exists. However, there has been some research proposing results interpretation methods based on various approaches LEED v4 According to Green Business Corporation Inc. (Singh, 2017), the latest published version of LEED included the life cycle assessment in its accreditation system with a specific section named Option 4 encouraging projects to make early design decisions to reduce environmental impact. The method leads to prioritise three categories including global warming potential from the six listed environmental impacts (GWP, ODP, AP, EP, POCP, depletion of non-renewable energy resources). The building is awarded three points by demonstrating a minimum of 10% reduction in addition to other requirements such as considering the minimum service life of at least 60 years, keeping the other categories without any increase and improving the energy of at least 5%. Also, an extra point is awarded through the Innovation credit by displaying a reduction in all six impact categories by 10%, instead of only three Soft comparative assertion method While the LEED method directly interpreted the environmental impacts values, another interpretation approach, the Soft comparative assertion method in the context of the EPD scheme for building products (Bozicek, et al., 2020) developed a process leading to a more decision-oriented interpretation of results when using EPDs in environmental building design. It consists of the calculation through three main steps of seven environmental categories assessed as adopted in the EPD framework (according to EN 15804:2012), resulting in simplified indicators. First, the normalisation step calculates a Percentage Share (PS) specific for each environmental category. Then by following two weighting principles, the

24 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 8 egalitarian and the footprint, the seven PS are reduced into two Impact Scores (IS). And through the final categorisation, which exerts the results of the soft comparative assertion method, the building designer can choose the preferable design alternative from the whole population IBO method Following a concept of results simplification, the Guidelines to Calculating Environmental Indicators for Buildings have been drawn up by the Austrian Institute for Healthy and Ecological Building (IBO) with the purpose of harmonising how environmental indicators for buildings (specifically, the OI3BGx indicators) are calculated (IBO, 2012). Using GWP (100 years in relation to 1994), AP and Total use of primary energy, the method first transforms the three assessed impacts into three sub-indicators calculated in a second step to result in an environmental indicator for 1 m 2 of a specific material. The final step leads to an environmental indicator for the whole layer of material in the building Summary Although the three explained approaches are not backed up by LCA scientific proofs justifying their methods choices and prioritisation, the authors presented clear processes to deal with the assessed environmental categories from numerical and mathematical points of view. Each method implements a comprehensible context to compare the results. In other words, the designer is guided for a simplified decision-making with full awareness of the process and the included environmental categories. Many factors can currently influence the adoption of one or more results interpretation approaches, and the importance relies upon its reasoning. Therefore, the continuous experimental application of any of the methods is key to leading one day for a global standardised scientifically proven results interpretation approach of LCA data for buildings. 2.2 LCA-BIM integration For the first time in the history of building design, the industry is amassing large volumes of highintegrity information and can understand the relationships among that data (Poljanšek, 2017). Therefore, by upholding the integrity and transparency of information across the life cycle of built assets, BIMenabled projects are more productive, predictable and profitable (Poljanšek, 2017). LCA data for buildings is getting available through EPD platforms (Eco-platform) and LCA databases, e.g., (Oekobaudat), which is the precondition for LCA-BIM integration. Different approaches of how to use this data and making it part of building design have been evolved Building modelling information (BIM) Advancements and innovations follow a slower pace in the AECO industry than in most other industries. In fact, when dealing with the built environment, it is not possible to move quickly from one approach

25 9 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. to another. However, this sector has been embracing new technologies that might shape its future in ways never seen before, as indicated in Figure 4. Digitalisation is one of the central innovations for existing buildings rehabilitation and for new construction processes enabling the implementation of new standards along the entire asset s life cycle, starting from the early design stage to the demolition phase. Through building information modelling (BIM), the information lives in 3-D models, applications and databases, becoming increasingly connected. Data is the key - its ownership and the ability to understand and act on it (Poljanšek, 2017). Figure 4 Future impact and likelihood of technologies (Poljanšek, 2017) The National Building Information Model Standard Project Committee in the United States defined BIM as a digital representation of physical and functional characteristics of a facility. A BIM is a shared knowledge resource for information about a facility forming a reliable basis for decisions during its lifecycle; defined as existing from earliest conception to demolition. BIM is regarded a multi-layered socio-technical system as it contains the technical core and the social part, which combines the manmade technology and the social and institutional consequences of its implementation in society (WSP, 2021). The technical core of BIM is the software which enables 3D modelling and information management (WSP, 2021). With this social and technical possibility of managing the process through BIM methodologies and tools, BIM opened many horizons for further developments in the AECO industry. It provides an appreciated opportunity to perform environmental performance analyses and sustainable development standards in the construction sector (Autodesk, 2008).

26 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration Existing approaches of LCA-BIM integration Achieving cleaner, low-carbon construction processes and greener job sites has become a significant concern in the construction sector (Wai Wong & Zhou, 2015). LCA analysis is one way to tackle the concerns, with the main limitation being the integrity and availability of communicated data. However, BIM facilitates communication and transparency among stakeholders and design teamwork in order to save time and energy, reduce costs and waste, minimise future errors and enhance working and living conditions (Najjar, et al., 2017). This will foster design innovation and creativity for the built environment industry, through the supply chain, and across other sectors (Edwards, et al., 2019). Also, BIM tools continue to increase the level of efficiency in supporting designers to analyse the building performance even in the early design stages. Therefore, multiple approaches have been developed to investigate the potential of integrating LCA in BIM methodologies and applications, as summarised in Table 1. Table 1 Comparison between the three BIM-LCA integration approaches. Approach 1 Approach 2 Approach 3 Data extraction from the model Application time Level of detail of the assessment Required skills level for designers Results clarity Alternatives comparability Licenses need Automation for data exchange Interoperability Manual/Script LCA Plug-in IFC Relatively slow Relatively fast N/A* Detailed Generic N/A High Low N/A Clear Very clear N/A Complex Simple N/A One Multiple One None/Partial/Full Partial Full Partial Partial Full * The approach is still not developed yet as an application so some information might be missing The most common link between BIM and LCA tools, defined in this dissertation as Approach 1, is the exchange of information via BoQ (Obrecht, et al., 2020). A schedule of the materials used and their quantities are extracted from the BIM model to connect it with an external database established by the assessors themselves or based on an existing one. Then, the data is imported into an LCA tool. The main

27 11 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. focus in this approach would be about the extraction and insertion process of data from the BIM software into the LCA tool which could be done manually by copying and pasting from one file to another. The process is very time-consuming and exposed to errors. Alternatively, data transfer can be automated through developed scripts and integrating different tools (Obrecht, et al., 2020). In Approach 2, the BIM model is used to generate and export a quantity take-off with information exchanged automatically through the use of LCA plug-in tools. The materials are mapped and identified from existing databases without needing to establish one by the authors. Studies that use the second approach are more recent due to the BIM technology advances and the market demand for more automatic analysis (Santos, et al., 2019). It enables fast results to optimise with generic data. However, using multiple tools might be limited with the need for multiple software licenses. Also, and most importantly, it is arguable that both the first and second approaches do not fulfil one of the most important goals of BIM interoperability, where LCA data are being stored in the BIM model. The researchers were still using the BIM to obtain information about the quantity of the materials (i.e., BoQ). However, BIM is a powerful environment and can provide much more information for LCA (Obrecht, et al., 2020). The third reviewed approach focuses on optimising the full potential of BIM. The process in Approach 3 suggests integrating the LCA analysis by including LCA/LCC information and results in the BIM model. The inclusion and accessibility of essential sustainability information such as the life cycle energy of materials can provide designers and decision-makers with a great insight into how sustainable each material is within their design to allow for accurate comparison between different sustainable designs variants (Edwards, et al., 2019). A set of professionals reviewed the approach and one of the observations was that it would be interesting to integrate LCC data within BIM objects instead of using external databases (Santos, et al., 2019). This might indeed be the most optimised approach for the BIM- LCA integration. However, the current IFC schema version is limited, requiring many developments to include LCA data correctly LCA and project design stages Building information modelling (BIM) tools have risen as a new trend in the construction industry to improve the sustainable assessments of buildings in the design phase (Santos, et al., 2019). According to the AIA guide for life cycle assessment (Bayer, et al., 2010), LCA is applicable at the three design stages of a project. It can start as early as before the model existence, during the Pre-design phase. At this stage, the LCA analysis is useful to define the environmental scope and goals of the project, and to influence decisions about the building footprint among several options and the choice of the structural system and assembly types by assessing elements individually. In other words, it starts by identifying the client/owner s requirements and preparing basic impact estimations. In the Schematic design stage,

28 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 12 the analysis can go further into the preliminary selection of building products and assemblies as well as the energy conservation measures. Whereas at the Design development stage, it is possible to go deeper and evaluate the life-long impacts of proposed lighting and HVAC systems, to identify environmental impacts and appropriate modifications to the system design, and to assess and choose material finishes. Figure 5 BIM data life cycle by BCG (Gerbert, et al., 2016) An important aspect to consider for the BIM-LCA integration process is the availability of data at each stage. BCG divides the BIM data life cycle in his article (Gerbert, et al., 2016) into three parts, starting with Design and engineering, to the Construction phase, ending the cycle with Operations as indicated in Figure 5. The Design and engineering stage states the data sources, the accumulation of data, and the modelling processes during four consecutive parts: the Concept, the Design (parametric modelling and object libraries), the Analysis (constructability-clash detection) and the Coordination of design disciplines. Another consideration from OneClickLCA (OneClickLCA, 2021) stated clearly the LCA capacity at various design stages (schematic, developed and detailed) by linking the analysis expectations to the level of detail of the model as shown in Figure 6. For example, in the Schematic phase with LOD 100, the data available is the approximate areas of the building envelope meaning that it is not possible to assign choices whereas at a Developed stage of LOD 200, it is possible to link the modelled elements to specific products. By overlapping and analysing the three mentioned classifications, as in the scheme of Figure 7, one can notice how the information and the reasoning behind each method complement the others. It is possible to know the data availability and level of detail at each stage. Therefore, the LCA analysis can be conducted with full awareness of the information accuracy and the degree of uncertainty. In other words,

29 13 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. a designer can clearly envision the probable scenarios as explained in Figure 8 and choose accordingly the most appropriate scope and goal for the case study. Figure 6 Level of development matched to the information availability (OneClickLCA) LCA tools and databases As a fundamental element in the considered approach for this methodology, the LCA tool covers the life cycle inventory phase by providing an extensive database of real-market construction products and calculates the impacts of each environmental category, hence, the impact assessment phase. Previously very time consuming, these two phases when using an LCA tool are now reduced to a simple data entry of a BoQ through various manual and automated means. Therefore, given the importance of the tool and its databases, it is essential to investigate what is being developed in the market from diverse backgrounds and locations in the world in order to use an adequate tool to run the assessment. OneClick LCA is one of the tools available in the market developed in Finland addressing the impact assessment of the whole life cycle of materials and construction. As described by the developers (OneClickLCA, 2021), the tool has access to the world s largest generic and EPD database with data complying with the European, North American and ISO standards. When available, it also contains country-specific information and can match localised data through local compensation methodology where a comprehensive LCA database is not available in an area. OneClick LCA is integrated for automation in other software, including multiple BIM tools (Excel, Revit, Solibri ), supports IFC 2 3 and IFC4 versions, offers custom integrations when needed, and complies with more than 40 certifications (LEED, BREEAM, DGNB ). Finally, and most importantly, the website contains publications that clearly determine the LCA compliances, considerations, and margin of error specifically to each LOD, including the early design process phase, which is very helpful from the designer s point of view.

30 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 14 Developed by KieranTimberlake in the United States, Tally quantifies a building or material's embodied environmental impacts to land, air, and water systems based on data available from EPDs, US life-cycle inventory and GaBi database (KieranTimberlake, 2021). As a Revit plug-in, it allows running real-time assessments at pivotal moments of various design options that show their differing environmental impacts. Results can then be broken down further by life cycle stage, Revit category, and Construction Specifications Institute (CSI) division displayed in graphics that are readily comprehensible and transparent. The tool requires no unique modelling practices, complies with EN/ISO standards covering the entire cradle-to-grave life cycle and reduces uncertainties by using proxy data where representative data are unavailable (Tally). Another tool on the market is Pleiades developed in France and used to make LCA for buildings and neighbourhoods (IZUBA). It evaluates twelve indicators, including energy resources, water, raw materials, health and biodiversity, and climate, with particular attention to global warming potential, based on the international Ecoinvent database, complying with the amended EN and ISO standards. It is also approved for BREEAM certification and allows to compare architectural variants, construction materials or energy sources in order to choose solutions with a lower environmental impact producing results in graphical display. Finally, Legep is a German tool used for new and existing buildings following the calculation rules of the German DGNB and BNB Sustainability Certification for making life cycle costs (LCC) based on DIN The tool is EN, ISO and DIN compliant and is based on the Ökobaudat database. In order to be more accurate and holistic in the review for a better tool choice, it is important to look further into the mentioned databases, the data providers for the tools. To begin with the Ecoinvent database (Ecoinvent), it is a global leader in creating the most transparent yearly updated life cycle inventory databases compliant with ISO/EN/PAS standards helping consumers adopt more environmentally friendly behaviour. It is now the only major database supporting three system models: Cut-off, Allocation at the Point Of Substitution (APOS) and Consequential data. Another data provider is the US Life Cycle Inventory Database (NREL) providing publicly available data including individual gate-to-gate, cradle-to-gate and cradle-to-grave accounting of the energy and material flows into and out of the environment that are associated with producing a material, component, or assembly in the United States. Also, the GaBi Database (GBCI) has by far the largest LCI data industry coverage worldwide compliant with ISO, EN, ILCD and EF standards. It is yearly updated and has Ecoinvent, U.S. LCI databases and EF Database integrated in it. And ultimately, Ökobaudat database is standardised for ecological evaluations of buildings by the Federal Ministry of the Interior, Building and Community in Germany offering life cycle assessment datasets on building materials, construction, transport, energy and disposal processes through generic and specific environmental declaration datasets, as well as EPDs. Used in many different building assessment systems, it is yearly updated, EN/BNB compliant and publicly available at no charge.

31 15 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Table 2 Comparison between the four LCA tools characteristics OneClick LCA Tally Pleiades Legep Geographical preferences No geographical preferences More specific to the US market More specific to the French market More specific to German market Level of integration in BIM Special skills requirements High Limited Limited - None None - Required Compliant to EN/ISO EN/ISO EN/ISO DIN/EN /ISO Certifications complying with 40+ certifications LEED BREEAM DGNB, BNB, NaWoh, ÖGNI Uncertainty level Defined for each LOD Limited using proxy data - Limited by the scalable/hierarchal data concept Scale of assessments Building Building Building and Neighbourhood Building Alternatives result comparability Available for many options Available for many options - Available for an anchor reference Results graphical interpretation Readily available, comprehensible Readily available, comprehensible Readily available, comprehensible Readily available, comprehensible Student license Free Free Purchased Purchased

32 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 16 Figure 7 Design development stages overlapped from 3 various sources Figure 8 LCA flow possibilities across the model development stages

33 17 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 3 METHODOLOGY The scope of this thesis focuses on integrating life cycle assessment into BIM in order to influence the design decisions and optimisation. Therefore, the proposed methodological framework intends to manage building data and assessment results from the building designers point of view. It identifies first the design phase during which an LCA analysis can most efficiently and sustainably influence decision-making and choices. Then, it compares LCA tools and develops an LCA-BIM integration workflow (section ). Finally, it visualises and interprets the results referring to three existing LCA results interpretation approaches. 3.1 Approach and overview In order to optimise the impacts, an LCA analysis must be conducted at an early phase of designing a construction project. However, while the assessment can be applied in a stage as early as before the initiation of the modelling, it is essential to understand that the earliest possible phase of a project does not necessarily mean the best one to conduct an LCA analysis fulfilling the purpose of the methodological framework. The foundation supporting information management and cooperation in BIM is the model itself. It contains integrated design and data through which stakeholders exchange and communicate over the entire life cycle of construction projects, which does not make the phase before the model optimal for the LCA application. Also, considering the maturity level of BIM implementation, a model at a conceptual level with a LOD 100 as identified by OneClickLCA (OneClickLCA, 2021) offers a limited amount of data. In contrast, a developed model at a LOD 300 or above is loaded with information. On the one hand, the scarcity of data limits optimisation efficiency through the LCA analysis dealing with a high level of uncertainty. On the other hand, an important load of information in the model offers correct data to optimise and propose changes. However, when dealing with such loads, the modification of the project would be very time-consuming, causing unwanted delays and sometimes not feasible, limiting the impact of the optimisation. Therefore, at the schematic phase, a model with a LOD 200 seems to offer the balance between generic and detailed, leaving an acceptable level of uncertainty without compromising the integrity of the data. It allows easy modifications to the projects when proposed as the result of the LCA impacts optimisation. While experts in the field are still figuring out the best interpretation of the LCA results, designers will not be able to go beyond experts and be aware of the best practice without a clear framework and benchmarks. In this vague situation, and to positively influence design decisions, the methodological framework proposes making the LCA analysis more adapted to the building designer s point of view. By linking environmental impacts to two other values (operational energy and costs), the results tend to become easily readable and positively influencing. It would be important to observe the LCA results, the operational energy values and the costs of several design options.

34 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 18 In conclusion, the proposed methodology tries to explore the relationship between the abstract LCA results and important concrete values, the operational energy and the building construction cost. The analysis is conducted at a schematic design stage with a LOD 200 within the BIM framework by adopting the approach of using an LCA plug-in tool for a BIM software. In addition, it complements the workflow with LCA results interpretation approaches in an attempt to facilitate decision making from a designer s point of view. 3.2 Application Having the general framework set, the implementation of the methodology requires further considerations defining the data flow and exploring the practical side in order to achieve tangible results. Therefore, the chronological steps of the application must be first identified along with the software and tools. And after figuring out the workflow, the proposed process will be applied on a case study to test the functionality and the outcome of the methodology Development and data flow The BIM environment chosen for the proposed framework is Autodesk Revit establishing an automatic data transfer from the model to the online OneClick LCA tool through an integrated plug-in. Also, as shown in Figure 9, the BIM software acts as the leading player in defining the whole data flow, including the operational energy simulation and the construction material cost estimation. Being from the same provider of Revit, Green Building Studio simulates the operational energy by taking information from the BIM model through an automatic transfer within the Autodesk environment or through a gbxml file extracted then uploaded in the online tool. Multiple cases can be simulated and stored inside Green Building Studio and downloaded as Excel files when needed as in the proposed workflow. In addition to the energy simulation, the cost estimation is applied directly in Revit by creating material take-off schedules. The environmental impacts of one or more cases are assessed and stored online in OneClick LCA, then extracted in Excel files. In order to rearrange the data according to the methodology s framework, the information needed are precisely selected from the model and the Excel sheets in a Dynamo script and displayed in a parallel coordinates chart through the Mandrill package for Dynamo. Figure 9 Workflow of the proposed methodology

35 19 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration LCA-BIM integration framework Building and design alternatives Building on the framework proposed, the methodology was tested on a case study using an exemplary BIM model publicly available from Autodesk Revit to validate the approach. It is a residential singlefamily house composed of 2 floors with an area of 297 m 2. As shown in Figure 10, the model contains partition walls, slabs, openings, external retaining walls, external slabs, and the roof. For the scope of the LCA analysis, all the modelled elements were considered. However, for the optimisation of the construction materials, the external walls and slabs were excluded, and the assigned material, reinforced concrete, remained the same in all the scenarios. Since the method focuses on the early design stages of a new building, the BIM model elements are represented in LOD 200, as pointed out previously in section 3.1. Figure 10 Schematic view of the BIM model in Revit Twelve design options were established in the BIM tool based on combinations of various building materials divided into three groups: concrete bricks or SIP for partitions and slabs, double or triple glazing for the openings, and finally, cellulose infill insulation, EPS or Rockwool for the insulating material. To manage the defined design variants, a naming convention was established matching between the design options and the extracted data files to keep the consistency of the exchanged information in the workflow. Many systems for organising information on buildings exist (e.g., OmniClass, Uniclass, Uniformat, etc.), which mostly share a hierarchical approach (acc. ISO ). In this case, Table 3 shows the reasoning followed for classifying the elements arranged inside Revit as a simple numerical hierarchy based on the various proposed material combinations.

36 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration Cost estimation After implementing the combinations in the BIM model as seen in Figure 11, the second step was to estimate the material costs. It is essential to mention that the thickness of the insulating layer has been modelled differently in each combination to keep the minimum energy requirements for the building s envelope equal in each option. For example, while the combination Wood Double gl Cellulose requires a layer of 15 cm of cellulose for the external walls to keep the Heat Transfer Coefficient (U) around 0.28 W/(m 2 K) and the Thermal Resistance (R) around 3.55 (m 2 K)/W, the option Wood Double gl EPS requires around 11 cm of EPS and the option Bricks Triple gl Cellulose needs 14 cm of cellulose infill insulation to reach the same U and R values. Therefore, the envelope elements have varying thicknesses across all the design options. The products prices have been collected from random online sources posting materials available for sale within the EU. However, the process was not a professional cost estimation for a construction project and is always open for further reviews by designers and experts since a non-expert set it up to fit a proposed academic framework. Appendix A shows tables of the cost estimation of design option. Table 3 Naming convention and combination for the proposed construction material Code Partitions and slabs Openings glazing Insulating material Wood Double gl Cellulose Wood Double gl EPS Wood Double gl Rockwool Wood Triple gl Cellulose Wood Triple gl EPS Wood Triple gl Rockwool Bricks Double gl Cellulose Bricks Double gl EPS Bricks Double gl Rockwool Bricks Triple gl Cellulose Bricks Triple gl EPS Bricks Triple gl Rockwool

37 21 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Figure 11 Design options as arranged inside the BIM model Energy simulation The following step was to simulate the operational energy for each of the twelve scenarios. Therefore, the energy analysis was run inside Revit to create an energy model, since the simulation tool is compatible with the BIM software. The analysis considered the model a single-family house in Ljubljana, Slovenia, with a gas boiler system for heating and a standard electrical system for cooling. The predefined operating schedules were used. Based on these settings, twelve gbxml files were exported from Revit and then uploaded in the Green Building Studio tool to run the simulation, as shown in Figure 12. Finally, the energy data was extracted as excel spreadsheets. All the exported files from the tools were stored adequately, respecting the naming convention. The various simulations were run to obtain a simplified value to compare the annual Energy Use Intensity (EUI) shown in Figure 13. However, the scenarios were not optimised and did not consider water usage, rainwater harvesting and the possible implementation of on-site renewable energy sources LCA implementation through Oneclick LCA After the cost estimation and the energy simulation, the following step was to conduct an LCA analysis. Comparing the four tools as seen in Table 2 along with their databases, OneClick LCA showed many advantages over the others, being more internationally adapted mainly concerning the data compliance to any geographical location and being more BIM integrated in various tools, software and file versions. Through the plug-in inside Revit, the tool takes out the quantities of the materials from the model accumulating all the design options together, even when only one option is selected as primary. For example, when estimating quantities for the Roof elements, one can notice the three proposed insulating

38 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 22 options (Cellulose insulation, Rigid insulation, Rock wool) as in Figure 14. The same applies to the rest of the elements. However, due to the parametric nature of the BIM environment, the LCA tool allows to choose extra information to add. It was possible to take an additional parameter Design option [Instance] from the model to be exported as an information field in the LCA tool. Therefore, when running the analysis, DESIGN OPTION appeared as a grouping criterion in the Combine phase, and when applied as the sole grouping parameter, all the materials of each design option were merged to be mapped as one element in the Mapping stage. However, the Combine phase leaves an ungroup option as shown in Figure 15, allowing individual mapping of each material. This way, only the desired design option was ungrouped, and the other merged ones were deleted from the analysis keeping only the related quantities and materials of the elements. Having the materials mapped initially in the LCA plug-in and then filtered correctly in the cloud, the analysis proceeded by setting the building area equal to 297 m 2 and the calculation period of 60 years for all the options. The annual energy consumption required electrical and fuel demands that were set differently and copied manually for each of the twelve designs from the extracted data of the simulations in Green Building Studio. The analyses did not take into consideration the water consumption and the construction site operations, and the scope and goal for the assessments were defined from the cradle to the grave including stages A1-A3, A4, B1-B5, B6, C1-C4, D missing A5 and B7. The assessment evaluated the impact of six main environmental categories available in the tool (GWP, AP, EP, ODP, POCP and Total use of primary energy) excluding the Biogenic carbon. In the end, twelve scenarios were generated in the LCA tool and extracted as Excel files respecting the proposed naming convention Data visualisation Finalising the production and extraction of all these data, the final and most important part of this methodology was to reach a new data display relating to the designer s point of view. Using simple visual scripting in Dynamo, it was possible to extract only the desired results from the cost estimation schedules in Revit and the vast amount of data available in the extracted excel files from GBS and OneClick LCA. Keeping a well-structured data directory (folders structure) and fixed files address is important to guarantee consistent data extraction during the workflow. A straightforward way for displaying and comparing results was found through Mandrill package showing the twelve options in a parallel coordinates chart. Appendix B shows the full script developed in Dynamo. This display was chosen due to the possibility of selecting any line in any of the columns and highlighting it, allowing easy comparison between one or multiple options across the analysed categories (vertical axis). Each graph consists in a total of nine vertical axes including one for the number of the thirteen variants, six for the environmental impacts, one for the operational energy (EUI) and finally, one for the cost estimation. The lines referring the design options were represented in one colour whereas the median value explained in is distinguished with additional post-processing on the graphs.

39 23 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Figure 12 Operational energy simulations in Green Building Studio Figure 13 Annual energy simulation showing the EUI value for the option Wood - Double gl Cellulose Figure 14 Data extraction from the BIM model to OneClick LCA tool through the Revit plug-in

40 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 24 Figure 15 Parameter section in the plug-in and grouping criteria in the online tool Results interpretation LCA-BIM integration method In addition to the twelve combinations, option thirteen was added in the display as the median value. It acts as an anchor for a better understanding of the results. Obtained in Dynamo, it is calculated by making the sum of the two central results from the lists of each environmental category, then dividing it by two. Keeping in mind the complexity of managing results in LCAs generally, the methodology intends to classify the outcome prioritising the embodied and operational impacts in first place, and then considering the cost estimation in second place. Therefore, the grouping considers the cases with energy and environmental impacts below the median option as the best performing results and the cases above it as the worst performing cases. A third group includes combinations having impacts with values both below and above the median option. This way, by choosing the best environmentally performing case,

41 25 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. a designer can be informed about the cost and check if it meets the budget. When it does not, less performing decisions might be taken keeping a close level of performance to the best one LCA results interpretation approaches Since the methodology is not an interpretation approach itself, the design options were calculated and classified according to three existing LCA results' interpretation methods to back up the proposed framework results. The consistency and the contribution of the proposed methodology for a better decision making was evaluated by the outcome of the three interpretation approaches explained previously in section and applied to the obtained results. The calculation for LEED v4 was performed in excel to take out the percentage of the difference between the chosen baseline case, in this case , and each of the other options (cases , and ). The Soft comparative assertion method was applied, and the results were calculated by the methodology s developers (Bozicek, et al., 2020), who also helped obtaining the IBO method s results.

42 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration RESULTS 4.1 Proposed methodology s outcome The results obtained were calculated based on the proposed framework (Section 3., Appendices A and B). The aim is more focused on exploring the LCA-BIM integration possibilities rather than obtaining completely accurate data. Therefore, the operational energy simulation, the cost estimation and the LCA results came out as reasonable values but are not considered the most precise results. Also, the graph in Figure 16 shows all the suggested options with readable categories and number. However, from Figure 17 to Figure 19 and in Appendix C, the graphs are fitted in a smaller format since it is more important to focus on the graph lines rather than reading numbers and categories. From a first observation based on the median values, the twelve options are grouped in first place as shown in Table 4. The order followed in this table is numerical based on the naming convention and does not represent any evaluation for the various combinations. It is true that the group of the best scenarios hosts three cases ( Wood Triple gl Cellulose, Wood Triple gl Rockwool, Bricks Triple gl Rockwool). However, one can be more clearly influenced after observing each option separately compared to the median. From these three cases, the design options showing the best performing results below the median value in the maximum number of environmental categories (3 out of 7) are two. The option have the best performing impacts in AP, EP and ODP as indicated in Figure 17, and the option shows the best performing values in GWP, POCP and Total use of primary energy as indicated in Figure 18. In the case of , the performance is the best concerning EUI and very close to the lowest impact in Total use of primary energy as in Figure 25. It is noted that the common element between these three cases is the triple glazing. Going further into the costs, shows the most expensive value, the median and as one of the least expensive. On the other hand, the designs showing the worst performing energy and environmental impacts are four ( Wood Double gl EPS, Bricks Double gl Cellulose, Bricks Double gl EPS, Bricks Double gl Rockwool). Having the highest impacts in 4 out of 6 categories (GWP, EP, AP and Total use of primary energy), in Figure 19 is by far considered the worst performing case followed by and as the second highest impacts as shown respectively in Figure 26 and Figure 27. The option comes at the bottom of this group as concluded from the graph in Figure 28. Concerning the costs, and are the least expensive in the twelve design options, whereas and are almost equal to the median cost. In this group, the common element between the four options is the double glazing.

43 27 Almezeraani, Y Making Life Cycle Assessment of Buildings a Part of Everyday Building Design Through BIM-based Integration. Master Dissertation Ljubljana, UL FGG, Second Cycle Master Study Programme Building Information Modelling - BIM A+. Figure 16 Parallel coordinates chart showing the results of the 13 design options

44 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 28 Concerning the last group which contains cases having impacts both below and above the median, comparing the cases becomes more complex and sub grouping is required to better observe the results. Most of the options ( Wood Double gl Rockwool, Wood Triple gl EPS, Bricks Triple gl Cellulose, Bricks Triple gl EPS) can be grouped together having at least 5 out of 7 categories equal or below the median. The mentioned options are seen respectively in the graphs Figure 29, Figure 30, Figure 31 and Figure 32. However, the case of Wood Double gl Cellulose stands alone having 6 out of 7 categories above the median as seen in Figure 33. About the costs, is the most expensive option available followed by and which are closer to the median and finally showing the only value below the median and the least expensive in this group. Appendix C contains the figures referenced starting from Figure 25. As noticed when comparing most of the environmental categories to the EUI, the values are matching and consistent in almost all the cases, mainly concerning the Global warming potential where both values vary proportionally. On the contrary, when considering the cost estimation, it is clear from the previous observations that the variation is random between the cases, making it harder to trace a pattern. Table 5 clearly shows the order of the design options as grouped by the methodology from 1 as the best performing case to 7 as the worst performing case, along with the cost estimation from the cheapest option to the most expensive starting from 1 to 12.

45 29 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Table 4 Grouping of the design options based on the median line All impacts below median Impacts below and above median All impacts above median Wood Triple gl Cellulose Wood Triple gl Rockwool Bricks Triple gl Rockwool Wood Double gl Cellulose Wood Double gl Rockwool Wood Triple gl EPS Bricks Triple gl Cellulose Bricks Triple gl EPS Wood Double gl EPS Bricks Double gl Cellulose Bricks Double gl EPS Bricks Double gl Rockwool Table 5 Ranking of the design options based on the impacts and the cost estimation Energy/environmental ranking Design options Cost ranking Wood Triple gl Cellulose Bricks Triple gl Rockwool Wood Triple gl Rockwool Wood Double gl Rockwool Wood Triple gl EPS Bricks Triple gl Cellulose Bricks Triple gl EPS Wood Double gl Cellulose Wood Double gl EPS Bricks Double gl Cellulose Bricks Double gl EPS Bricks Double gl Rockwool 1

46 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 30 Figure 17 Chart highlighting the best performing cheap option Bricks Triple gl Rockwool and the median value Figure 18 Chart highlighting the best performing most expensive option Wood Triple gl Cellulose and the median value Figure 19 Chart highlighting the worst performing cheapest option Bricks - Double gl Rockwool and the median value

47 31 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 4.2 Decision making with various LCA results interpretation methods LEED v4 interpretation outcome Taking into consideration existing results interpretation methods, the LEED v4. requires considering a baseline case and improving it as explained previously (Section ). The cases having the best performing impacts , and are eligible for the three main points when compared to the baseline, showing a reduction of more than 10% in GWP and no increase in the other categories. Moreover, with a small effort to improve the EP, AP and ODP categories, the case can become eligible also for the extra point awarded through the Innovation credit by displaying reduction in all six impact categories by 10%. On the other hand, the cost, not considered by the LEED method for LCA, shows a considerable increase of 15.63% more than the baseline when shifting from to whereas it is a difference of 7.93% from to and 2.6% only when improving from to Table 6 Improvement percentage calculated for 3 design options according to the LEED method Global warming [kg CO2e] Acidification [kg SO2e] Eutrophication kg [PO4e] Ozone depletion potential [kg CFC11e] Formation of ozone of lower atmosphere [kg Ethenee] Total use of primary energy ex. raw materials [MJ] EUI [MJ/m²/year] Cost estimation [euros] Improvement 1 (from to ) 12.93% 9.40% 4.82% 7.10% 10.86% 12.35% 14.07% % Improvement 2 (from to ) 12.54% 8.24% 3.48% 6.71% 9.66% 12.30% 15.43% -7.93% Improvement 3 (from to ) 11.90% 9.84% 6.08% 10.28% 10.56% 11.35% 14.12% -2.60% Soft comparative assertion interpretation outcome Concerning the soft comparative assertion method, the population entities resulted all in the category A having an equivalent environmental impact as seen in Figure 20. In this case, the EUI and the cost can determine the preferred sustainable design. With a closer look to the results, the impact scores calculated based on the egalitarian and the footprint principles arrange the entities in a more detailed approach from the lowest to the highest score. Classifying the options as in the charts of Figure 21, the cases , and showed again as the options with the best performing environmental impact, the same

48 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 32 as the initial classification. Also, the option with the worst performing impact in this methodology was instead of initially, however, both cases have very high values for impacts and EUI, and have the two lowest cost estimations. The common point between the proposed methodology and the Soft comparative assertion method is that both are inclusive for all the impacts. Therefore, the classifications came almost the same with slight differences in the order and with one exception in the case showing a considerable gap between the two methods. The differences are due to the fact that the Soft comparative assertion calculates the impact scores from numerical assessed impacts making it more accurate than the proposed methodology that classifies the results graphically. However, it is slightly less expansive by not including the costs and by not giving the EUI an additional decisional relevance IBO interpretation outcome The final interpretation approach is the IBO method calculating OI3 indicators considering only three environmental categories: GWP, AP and Total use of primary energy. The option had the highest performing impacts followed by and then having all very close values as shown in Figure 22. The worst indicator was shown by the option unlike previous classifications where it was Also, many differences of high gaps in the ranking as seen in Table 7 were observed between the proposed methodology and the IBO method caused mainly by the fact that the last one calculates only three impacts whereas the proposed method considers six environmental impacts, operational energy and cost. Figure 20 Soft comparative assertion method final categorisation with design options ordered from the bottom having the highest impact score to the top having the lowest impact score

49 33 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Figure 21 Impact scores of the Soft comparative assertion based on the egalitarian and footprint principles Figure 22 OI3 indicators calculated for the design options based on the IBO method 4.3 Evaluation of the approaches In this case study, adding the operational energy to the LEED approach for LCA by the side of the environmental impacts made easier monitoring the annual demand difference between the baseline and the other cases. The cost showed the possibility of choosing improved cases with different budget variation having very close environmental impacts. However, it did not present a ranking of all the cases based on the calculated values since it requires only one baseline and demonstrating one case with enough improvements, the reason that makes it missing in Table 7. Concerning the Soft comparative assertion method, the inclusion of the operational energy and the cost was seen beneficial in this case study because the compared alternatives were classified almost equal with close environmental characteristics. This fact offers a potential for the EUI and the cost in determining the preferred sustainable designs. Finally, the IBO method functions in the opposite way of the proposed framework in this dissertation by eliminating categories to simplify the interpretation instead of adding values. All the mentioned methods were an added value complementing the results of the proposed methodology. It is always beneficial to apply and experiment with diverse LCA results interpretation

50 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 34 approaches. However, when it comes to decision making, the Soft comparative assertion offered the most suitable approach complementing the proposed framework for early design decisions from a designer s point of view. Table 7 Ranking comparison based on the LCA results of the proposed and existing approaches Design options Proposed methodology s ranking Soft comparative assertion ranking IBO ranking Wood Triple gl Cellulose 1 A(2) Bricks Triple gl Rockwool 1 A(1) Wood Triple gl Rockwool 2 A(3) Wood Double gl Rockwool 3 A(7) Wood Triple gl EPS 3 A(4) Bricks Triple gl Cellulose 3 A(5) Bricks Triple gl EPS 3 A(6) Wood Double gl Cellulose 4 A(8) Wood Double gl EPS 5 A(9) Bricks Double gl Cellulose 6 A(10) Bricks Double gl EPS 6 A(12) Bricks Double gl Rockwool 7 A(11) 10

51 35 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 5 DISCUSSION The main outcome of the thesis is the methodology developed and presented in this research to compare results obtained from multiple LCA analysis. Because buildings are complex systems consisting of a myriad of different components, and because modern building design is getting increasingly digitalised (e.g., the implementation of BIM), a substantial number of design alternatives can be compared during the design process (Bozicek, et al., 2020). Through the exchange of information from the BIM model to the LCA tool, and then through the data processing with Dynamo, the workflow introduced a new display to visualise the results comparison more clearly. In addition to the assessed environmental categories, the operational energy and the cost estimation were found interesting to add in the comparison bringing the process closer to the designer s point of view. All calculated inside the BIM environment, such values act as an indicator relating easily to the designer, hence the client. 5.1 Additional real-life case study The proposed methodology was applied in the first case study on a BIM model at a schematic design stage with a LOD 200. During the dissertation development, an opportunity was offered to use the model of an actual project; Treviso Hospital (Figure 23), developed in Veneto in Italy by L+Partners, an architecture company based in Milan. The project was already in an advanced construction phase, and the BIM model had a LOD 300. Therefore, an LCA analysis was conducted with the scope including only internal finishing materials for walls, floors and ceilings shown in Table 8, which were already included in the BIM model but still not executed in the building. Despite the advanced development stage of the project, the developers considered the assessment important due to the typology of the building. Optimisation is indeed complicated with the limited spectrum of material options and strict requirements, yet the assessment of the embodied energy remains a point of interest. Generally, a hospital needs a lot of maintenance and hygienic treatments requiring the replacement of the materials with a higher frequency than in other building types. Table 8 Total quantities of the modelled finishing materials PVC flooring Ceramic tiles Vinyl wall covering Wall paint Rockwool false ceiling Area (m2) Lifecycle 25 yrs. As building 25 yrs. 10 years As building

52 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 36 Figure 23 Photos of the on-going construction taken on site by L+Partners team The scope of this LCA analysis included only the mentioned finishing materials in Table 8 assessed from cradle to grave considering the life cycle of the building for 50 years and the location in Treviso, Italy. The proposed methodology is functional on buildings as well as on entities or groups of elements. Therefore, to apply it in this case, other finishing material alternatives must be assessed. The options were designed simply as a material replacement for the PVC flooring only, one of the most extensively used materials as seen in Table 9 and the costs were calculated based on values provided by the team from the project contract signed in 2015 and by online references. Clearly, the EUI was excluded since the scope was defined only for finishing materials. The quantities were all extracted from the model except for the wall paint which was estimated by the team in the studio.

53 37 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. The methodology had to be adapted to the scope of the analysis because the quantities were already prepared and there was no need to extract data from various sources. As a result, the majority of the values were entered manually, and the script was used only to illustrate the results as in Figure 24. Based on the outcome, it was concluded that the best material for the flooring is the Linoleum (1.2.1.) followed by the PVC (1.1.1.) which is the company s choice, then the rubber (1.3.1.). It was also pointed out in the case that the less ceramics are used, the lower the environmental impacts are. Furthermore, adding the costs showed that the best performing case is the cheapest one. At the end, the team evaluated any probable change for a better alternative and did not suggest proceeding with the best choice because any modification in the model, even at the level of the finishing material, requires extensive work causing unnecessary delays. The LCA analysis was kept as an informational source about the building and was considered a key research for future projects introducing the company to a BIM integrated approach for LCA through OneClick LCA tool. Table 9 Table showing the alternative options for the flooring

54 Almezeraani, Y Making Life Cycle Assessment of Buildings a Part of Everyday Building Design Through BIM-based Integration. 38 Master Dissertation Ljubljana, UL FGG, Second Cycle Master Study Programme Building Information Modelling - BIM A+. Figure 24 LCA results and cost for different flooring options

55 39 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 5.2 Evaluation and considerations It is highly important to point out that the outcome of the dissertation is not a tool, but a workflow of data management guiding for an LCA-BIM integration framework with a better display of information found hard to compare in their original arrangement. Moreover, to obtain the desired display, there are important notices to consider when applying the developed methodology. First and most importantly, it was pointed out and confirmed from a real project situation that it is fundamental to apply the method on a project in an early schematic design stage in order to be functional and efficient as indicated in the main case study. Also, since the aim is to include multiple design options, the whole process of accurate and correct information selection relies on the names and the files location. Therefore, it is important to establish a naming convention at the earliest stage of the application and follow it strictly for files and design options along with a fixed directory keeping the same files address and folder s structure. Also, it was found very important not to skip any step of the process and respect their chronology during the application. Otherwise, the data will be randomly selected or not selected at all. The main advantage of the proposed BIM-LCA integration framework is that it extracts all the information from the model. This supports one of the fundamental principles of BIM by using the model as a permanent and updated data repository. Also, the BIM-based environment enhanced the accurate data filtering at a conceptual design level model due to its parametric nature and provided a simple application process more adapted to the designers process rather than to environmental experts. Furthermore, the results visualisation remains clear no matter how extensive the number of the compared design options is, due to the dynamic nature of the display, allowing to select and highlight one or more options. Also, it was found that by adding a median value of all the populations, the results became more readable and more contextualised resulting in a better understanding of the cases performances. On the other hand, multiple limitations hinder the potential of the proposed framework, and one of them is the one-way data flow that affects fundamentally and directly the methodology. It presented the lack of ability to reverse the data flow between steps, which reduces the efficiency of the application. Other limitations relate to external facts such as the need for multiple licenses to obtain the right to use the tools, the need for additional experts to automate the steps held manually, and the LCA software's capacity to handle large models with an extensive number of elements and objects. The data accuracy is not the centre point of this methodology, the data flow is. The results were treated in the proposed framework as separate values and the classification prioritised the energy and environmental impacts over the cost estimation. Three options (1.2.1., and ) were identified having all the impacts below the median and four cases (1.1.2., , and ) having the impacts above. The rest of the options had impacts split above and below the median and were subdivided into two groups consisting of impacts mostly above or mostly below. In a following step, the cost variation was observed for the options of each group. The annual energy demand matched the

56 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 40 environmental impacts, whereas the variation was more random concerning the cost estimation. Specifically, in this case study, the operational energy was the main driver in the LCA impacts because it was not optimised. However, in the future, materials will be the dominant source of CO 2 emissions from buildings (Zijlstra, 2021). Therefore, the importance of the proposed methodology relies not only on the current schemes but on future analyses to identify the main drivers in the LCA optimisation other than the operational energy. Concerning the cost estimation, the results showed that an optimised option could be achieved without being the most expensive case, keeping in mind that the process and values of the estimation are always open for further verifications and that the random cost variation between the options could be partially attributed to the uncertainty in the cost estimation. In order to assess better the framework and evaluate the methodology s contribution for a better decision making closer from a designer s point of view, three LCA results interpretation approaches were applied (LEED, Soft comparative assertion and IBO). It was noticed that the methods including all the environmental categories, in this case the LEED v4. and the Soft comparative assertion, showed identical or very close classification to the initial one of the proposed methodology. However, methods excluding some environmental impacts like the IBO approach, which considers only 3 categories out of 6, showed different results and rankings. Therefore, the application of the proposed methodology is functional and contributes more to inclusive results interpretation contexts where none of the environmental categories are eliminated. However, even in a context complemented with other sustainability topics (Energy-Costs), LCA results could be found hard to interpret. To sum up, by comparing LCA results within each other and with important values like the operational energy and costs within a BIM-based environment, it is expected that designers will be efficiently influenced to take early design decisions based on the analysed results. Also, as included in the proposed methodology, it is important to complement the results by applying other LCA results interpretation methods helping the designer to rely more on scientific frameworks to make choices rather than his own subjective opinion.

57 41 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 6 CONCLUSIONS The need for optimised building designs through LCA is rising and integrating it within BIM is more crucial than ever to improve the analysis time and the data accuracy, hence the whole design process. The proposed methodology is not an LCA results interpretation approach nor an assessment tool. It is a workflow of data management integrated within a BIM-based environment driven by the aim to bring the LCA results closer to the designer s point of view, in other words, to the decision-makers. Current LCA tools show the analysis results and compare multiple options. However, many values used during the LCA analysis that are important to sustainable thinking remain invisible. Bringing up these values, the aim is to facilitate the decision-making process for designers based on LCA results at an early design stage. Backed by the demonstration s results, comparing values with clear benchmarks side by side to values that do not have a defined baseline in the proposed dynamic display enhances the sustainable approach of the analysis. This method presents a different choice and way of data display to positively influence the decisions taken by building designers at an early design stage. While it does not provide a direct solution for the critical results interpretation part, the outcome helps for a better visualisation. It also discovers the potential of BIM as a suitable environment for the integration and inclusion of all the results, whereas it is evident that it is still a long way to reach the full capacity of digitalisation and BIM. In addition, it goes beyond the BIM-LCA integration framework to the results interpretation phase clarifying the context of the methodology s functionality when coupled with existing interpretation approaches, hence emphasising its usefulness. Getting a closer step to the problem equals getting closer to the solution. By developing the proposed methodology, the BIM environment has been the major contributor for stepping closer to understanding the LCA process and results. Therefore, for a more reliable interoperable LCA-BIM integration, it is essential to have a BIM model enriched with LCA data at the product/element level since the early design stage generating and updating the LCA results automatically. Also, without a correct guidance at the LCA results interpretation step, building designers can make different environmental decisions, influencing their design options. Currently, different methods enable different outcomes, and the results can be hard to interpret for building designers. This is specifically important for BIM based design, where many alternatives can be compared. To sum up, while the LCA-BIM integration is becoming more and more achievable, the LCA results interpretation should have a standardised tool for results interpretation in order to simplify the decision-making process for the building designer.

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62 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 46 APPENDICES APPENDIX A: Cost-estimation Revit schedules for design option Wood Double gl Cellulose Wall Material Takeoff Material: Name Material: Volume Material: Cost Material cost per volume Air 2.19 m³ 0 Cellulose insulation 3.45 m³ Cellulose insulation 0.99 m³ Cellulose insulation 3.09 m³ Cellulose insulation 1.31 m³ Cellulose insulation 0.90 m³ Cellulose insulation 9.38 m³ Cellulose insulation 5.81 m³ Cellulose insulation 5.88 m³ Cellulose insulation 1.13 m³ Cellulose insulation 0.50 m³ Cellulose insulation 1.93 m³ Cellulose insulation 6.47 m³ CL Concrete_ panels 6.80 m³ CL Concrete_ panels m³ CL Concrete_ panels m³ CL Concrete_ panels m³ CL Concrete_ panels 2.69 m³ CL Concrete_ panels 7.73 m³ Concrete - Cast In Situ 7.60 m³ Concrete - Cast In Situ m³ Concrete - Cast In Situ 4.23 m³ Concrete - Cast In Situ 7.99 m³ Concrete - Cast In Situ 5.99 m³ Concrete - Cast In Situ 4.02 m³ Concrete - Cast In Situ 3.82 m³ Concrete - Cast In Situ 5.30 m³ Concrete - Cast In Situ 2.50 m³ Concrete - Cast In Situ 2.50 m³ Concrete, Cast In Situ 9.00 m³ Concrete, Sand/Cement Screed 0.50 m³ 9.98 Concrete, Sand/Cement Screed 0.14 m³ 2.86 Concrete, Sand/Cement Screed 0.45 m³ 8.93 Concrete, Sand/Cement Screed 0.19 m³ 3.8 Concrete, Sand/Cement Screed 0.13 m³ 2.61 Concrete, Sand/Cement Screed 1.36 m³ Concrete, Sand/Cement Screed 0.91 m³ 18.12

63 47 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Concrete, Sand/Cement Screed 0.91 m³ Concrete, Sand/Cement Screed 0.16 m³ 3.27 Concrete, Sand/Cement Screed 0.07 m³ 1.45 Concrete, Sand/Cement Screed 0.28 m³ 5.6 Concrete, Sand/Cement Screed 0.94 m³ Finishes - Exterior - Timber 0.20 m³ 0 Cladding Finishes - Exterior - Timber 0.00 m³ 0 Cladding Finishes - Exterior - Timber 0.00 m³ 0 Cladding Finishes - Exterior - Timber 0.00 m³ 0 Cladding Finishes - Interior - Gypsum Wall 0.16 m³ 9.54 Board Finishes - Interior - Gypsum Wall 0.16 m³ 9.69 Board Finishes - Interior - Gypsum Wall 0.12 m³ 7.32 Board Finishes - Interior - Gypsum Wall 0.46 m³ Board Finishes - Interior - Gypsum Wall 0.69 m³ Board Finishes - Interior - Gypsum Wall 0.25 m³ Board Finishes - Interior - Gypsum Wall 0.24 m³ 14.4 Board Finishes - Interior - Gypsum Wall 0.12 m³ 7.3 Board Finishes - Interior - Gypsum Wall 0.35 m³ Board Finishes - Interior - Gypsum Wall 0.26 m³ Board Finishes - Interior - Gypsum Wall 0.12 m³ 6.93 Board Finishes - Interior - Gypsum Wall 0.10 m³ 5.72 Board Finishes - Interior - Gypsum Wall 0.26 m³ Board Finishes - Interior - Gypsum Wall 0.12 m³ 6.94 Board Finishes - Interior - Gypsum Wall 0.24 m³ Board Finishes - Interior - Gypsum Wall 0.19 m³ Board Finishes - Interior - Gypsum Wall 0.05 m³ 2.82 Board Finishes - Interior - Plasterboard 0.30 m³ 17.7 Finishes - Interior - Plasterboard 0.08 m³ 5.07 Finishes - Interior - Plasterboard 0.26 m³ Finishes - Interior - Plasterboard 0.11 m³ 6.74 Finishes - Interior - Plasterboard 0.08 m³ 4.63 Finishes - Interior - Plasterboard 0.80 m³ Finishes - Interior - Plasterboard 0.47 m³ Finishes - Interior - Plasterboard 0.47 m³ Finishes - Interior - Plasterboard 0.10 m³ 5.79 Finishes - Interior - Plasterboard 0.04 m³ 2.57 Finishes - Interior - Plasterboard 0.17 m³ 9.92 Finishes - Interior - Plasterboard 0.55 m³ Metal Stud Layer 0.40 m³ 0 Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB Structure - Timber Insulated Panel - OSB 0.68 m³ m³ m³ m³ m³ m³ m³ m³ m³

64 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 48 Panel - OSB Structure - Timber Insulated 0.10 m³ 99 Panel - OSB Structure - Timber Insulated 0.38 m³ Panel - OSB Structure - Timber Insulated 1.28 m³ Panel - OSB Wood - Stud Layer 0.87 m³ Wood - Stud Layer 0.89 m³ Wood - Stud Layer 0.67 m³ Wood - Stud Layer 0.57 m³ Wood - Stud Layer 0.16 m³ Wood - Stud Layer 0.51 m³ Wood - Stud Layer 0.22 m³ 108 Wood - Stud Layer 0.15 m³ Wood - Stud Layer 1.54 m³ Wood - Stud Layer 1.02 m³ Wood - Stud Layer 1.03 m³ Wood - Stud Layer 2.32 m³ Wood - Stud Layer 3.44 m³ Wood - Stud Layer 1.23 m³ Wood - Stud Layer 1.20 m³ Wood - Stud Layer 0.61 m³ Wood - Stud Layer 1.73 m³ Wood - Stud Layer 1.28 m³ 642 Wood - Stud Layer 0.58 m³ Wood - Stud Layer 0.48 m³ Wood - Stud Layer 0.19 m³ Wood - Stud Layer 0.08 m³ Wood - Stud Layer 1.29 m³ Wood - Stud Layer 0.32 m³ Wood - Stud Layer 1.06 m³ Wood - Stud Layer 0.58 m³ Wood - Stud Layer 1.20 m³ Wood - Stud Layer 0.97 m³ Wood - Stud Layer 0.24 m³ Grand total: m³

65 49 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Curtain Panel Material Takeoff Type Material: Area Material: Cost Cost per Area Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 3 m² Double glazed 3 m² Double glazed 3 m² Double glazed 1 m² Double glazed 3 m² Double glazed 3 m² Double glazed 1 m² Double glazed 3 m² Double glazed 3 m² Double glazed 4 m² Double glazed 3 m² Double glazed 3 m² Double glazed 3 m² Double glazed 1 m² Double glazed 1 m² Double glazed 1 m² Double glazed 1 m² Double glazed 1 m² Double glazed 1 m² Double glazed 1 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 3 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 3 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 4 m² Double glazed 3 m² Double glazed 1 m² Grand total: m²

66 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 50 Window Schedule Type Family Heat Transfer Coefficient (U) Cost 1180 x 1170mm Double glazed M_Skylight W/(m² K) x 1170mm Double glazed M_Skylight W/(m² K) 470 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Standard Double glazed Single Window W/(m² K) 230 Grand total: Floor Material Takeoff Material: Name Material: Volume Material: Cost Cost per volume Carpet (1) 1.63 m³ 0 Cellulose insulation 0.90 m³ Cellulose insulation 7.94 m³ Cellulose insulation 5.57 m³ Concrete, Cast In Situ 6.73 m³ Concrete, Cast In Situ m³ Concrete, Cast In Situ 4.58 m³ Concrete, Sand/Cement Screed 1.92 m³ Concrete, Sand/Cement Screed 3.50 m³ Concrete, Sand/Cement Screed 1.31 m³ Damp-proofing 0.00 m³ 0 Damp-proofing 0.00 m³ 0 Damp-proofing 0.00 m³ 0 Rigid insulation 1.92 m³ SH_resin Floor 2.65 m³ SH_resin Floor 0.54 m³ SH_resin Floor 2.65 m³ SH_resin Floor 2.50 m³ Site - Hardcore 5.77 m³ 0 Structure - Timber Joist/Rafter Layer 4.05 m³ Structure - Timber Joist/Rafter Layer m³ Structure - Timber Joist/Rafter Layer m³ Structure - Timber Joist/Rafter Layer m³ Grand total: m³

67 51 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. Floor Material Takeoff Material: Name Material: Volume Material: Cost Cost per volume Carpet (1) 1.63 m³ 0 Cellulose insulation 0.90 m³ Cellulose insulation 7.94 m³ Cellulose insulation 5.57 m³ Concrete, Cast In Situ 6.73 m³ Concrete, Cast In Situ m³ Concrete, Cast In Situ 4.58 m³ Concrete, Sand/Cement Screed 1.92 m³ Concrete, Sand/Cement Screed 3.50 m³ Concrete, Sand/Cement Screed 1.31 m³ Damp-proofing 0.00 m³ 0 Damp-proofing 0.00 m³ 0 Damp-proofing 0.00 m³ 0 Rigid insulation 1.92 m³ SH_resin Floor 2.65 m³ SH_resin Floor 0.54 m³ SH_resin Floor 2.65 m³ SH_resin Floor 2.50 m³ Site - Hardcore 5.77 m³ 0 Structure - Timber Joist/Rafter Layer 4.05 m³ Structure - Timber Joist/Rafter Layer m³ Structure - Timber Joist/Rafter Layer m³ Structure - Timber Joist/Rafter Layer m³ Grand total: m³

68 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 52 APPENDIX B: Dynamo script as run on the design option Wood Double gl Cellulose The dynamo script developed for the methodology is composed of two parts. Part 1 extracts the correct data from the exported spreadsheets and Part 2 is responsible of the charts creation. In order to well understand the steps, a general overview shows below the main script composition with key numbers referring to enlarged pictures of each part in the following pages. Part 1: Data extraction to excel Part 2: Parallel coordinates data display from the excel file

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71 55 Almezeraani, Y Making Life Cycle Assessment of Buildings through BIM-based Integration. 1.4.

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