This master thesis investigated the influence of prefabrication rate of buildings on the embodied environmental impacts. Through a comparative attributional LCA four different Swedish buildings were investigated to explore the influence of PR on the environmental impacts in the categories Cumulative Energy Demand, Global Warming Potential, Water Consumption, Fossil Resource Scarcity, and Mineral Resource Scarcity. The reference buildings had prefabricated rates of 14, 26, 38 and 91%. The results indicate that a higher prefabricated rate (PR) can lead to a lower impact in these categories to some extent; mainly due to a lower amount of total concrete material per square meter, dependent on the construction method used. The most influential materials in the comparison where cement and steel. An initial improvement of several impacts was seen when the PR of concrete buildings increased from 14% to 38%, with one reason being increased material efficiency of concrete. When further increasing PR, it is not certain that impacts necessarily continue to improve, as no clear difference was shown between the buildings with PR of 91% and 38%. This seems to point towards that any clear relationship between PR and the chosen impact categories breaks down or flattens out for higher prefabricated rates, and that the most beneficial solution often could be a semi-prefabricated construction method. This is concurrent with previous results in the current body of literature on LCA of construction and prefabricated rates. Instead, for additional reduction of environmental impacts after this point, other factors such as material choice and could become increasingly important. Additionally, the question of which impact category to prioritize arises. / Denna masteruppsats undersöker betydelsen av andelen prefabricerad betong i byggnader och dess påverkan på den inbyggda miljöpåverkan. En jämförande bokförings-LCA gjordes av fyra svenska referensbyggnader för att undersöka prefabrikationsgradens inverkan i fem kategorier av miljöpåverkan: kumulativ energiförbrukning, global uppvärmning, vattenförbrukning, och förbrukning av minerala och fossila naturresurser. Referensbyggnaderna hade prefabricerade andelar av 14, 26, 38 och 91%. Resultaten indikerar att en högre grad av prefabricering kan leda till en lägre påverkan i de undersökta kategorierna i viss mån, inte minst på grund av en lägre total förbrukning av betong per kvadratmeter BTA, beroende på vilken konstruktionsmetod som används. De mest betydelsefulla råmaterialen fanns vara cement och stål. En initial förbättring i flertalet kategorier syntes när prefabrikationsgraden ökade från 14 till 38%, mycket tack vare den lägre betongförbrukningen. När prefabrikationsgraden steg ytterligare till 91% syntes ingen tydlig förbättring, och det kan inte anses klarlagt att en högre prefabrikationsgrad nödvändigtvis har lägre miljöpåverkan. Detta indikerar att den mest fördelaktiga lösningen ofta kan vara en semi-prefabricerad lösning, vilket överensstämmer med resultaten i tidigare studier på området. För ytterligare reducering av miljöpåverkan efter en viss grad av prefabricering framstår andra faktorer såsom materialval som allt viktigare.

Biokol är en återstod från pyrolys av hållbar biomassa som exempelvis trädgårdsavfall och har många användningsområden. Produktion av biokol räknas ofta som en Negative Emission Technology som kan användas för att mildra klimatförändringarna och bidra till en hållbar utveckling. Detta projekt undersöker genom en förenklad komparativ livscykelanalys hur bostadsbolaget Stockholmshem AB på ett klimatvänligt och effektivt sätt kan producera biokol från sitt egetproducerade trädgårdsavfall. Tre potentiella tillvägagångssätt formulerades för hur företaget på olika skalor och med olika tekniker skulle kunna utföra en sådan produktion och sedan använda producerat biokol för plantering i sina bostadsområden. Även ett referensscenario baserat på nuvarande verksamhet formulerades och jämfördes med de tre potentiella scenarierna. För att underlätta utvärdering av effektivitet utfördes även en översiktlig kostnadsanalys av Stockholmshems utgifter kopplade till omhändertagande av trädgårdsavfall. Utvärderingen indikerade att Stockholmshem genom implementering av biokol i verksamheten kan minska sina utsläppsnivåer jämfört med befintligt system. Utsläppsminskningens storleksordning kan främst antas bero på vilken typ av produktionsteknik som används, där en högteknologisk pyrolysenhet leder till mest producerat biokol och maximal klimatprestanda. Kostnaderna för hantering av trädgårdsavfall kan potentiellt både minska och öka vid implementering av biokol i företagets verksamhet. / Biochar is a product that is created through the pyrolysis of sustainably sourced biomass. The production of biochar is considered a negative emission technology and can be used to mitigate climate change and contribute to sustainable development. The aim of this project was to determine how Stockholmshem AB in an efficient and climate friendly way can produce biochar from the garden waste generated by their own activities. To determine this, an assessment was carried out using a simplified comparative life cycle assessment of three scenarios, which were differentiated by scale, for how Stockholmshem could produce biochar. The scenarios were also compared in relation to a reference scenario designed to mirror the company’s current management of garden waste, which relied on incineration for district heating. To furthermore assess the effectiveness of the scenarios, a simple costing analysis was executed as well as an uncertainty and sensitivity analysis.  The assessment indicates that implementation of biochar in Stockholmshem’s operation in all scenarios results in reduced emissions compared to the reference scenario. An important factor for environmental performance was shown to be the scale of biochar production. A high-tech and large-scale pyrolysis unit both contributed to decreased emissions from pyrolysis and a larger amount of produced biochar which in turn led to more sequestrated carbon with further improvements in climate performance. In terms of economics, the most efficient way of producing biochar for the company can be assumed to involve internalized production due to reduced costs for waste disposal. Implementation of biochar production can potentially both lead to reduced and increased costs regarding disposal of garden waste for Stockholmshem.

The building sector is resource intensive and contributes significantly to Climate change. In recent times, many initiatives are being undertaken to make today’s situation better. Among them, the Circular economy has become an attractive topic for implementation of sustainability in various sectors.  A case study has been performed to assess the environmental impacts of a ‘circular’ kitchen at Chainable company in the Netherlands through life cycle assessment. This kitchen is different from other standard kitchens as it is offered as kitchen-as-a-service for a long period of time. It follows circular design strategies such as extension of service life, use of recycled materials, design-for- disassembly and design for light weight construction. The company maintains the kitchen and ensures that it is circular by either recycling, reusing or recovering the waste at the end-of-life of the kitchen. This could potentially reduce the impacts of construction of more kitchens if people and different organizations keep it for the long term.  The kitchen is made of various components such as frame, panels, sink, tap, drawers, countertop, handles and electric socket. The use phase of the kitchen includes repair and maintenance scenarios for the whole lifecycle of the kitchen.  The results indicate production and replacement of Chipboard panels, production of steel frame and transports linked to repair and maintenance scenarios as hotspots of the kitchen in Climate change and Resource use impact categories. / Byggsektorn är resurskrävande och bidrar avsevärt till klimatförändringarna. På senare tid har många initiativ tagits för att göra dagens situation bättre. Bland dem har cirkulär ekonomi blivit ett attraktivt ämne för genomförandet av hållbarhet inom olika sektorer.  En fallstudie med hjälp av livscykelanalys har utförts för att bedöma miljöeffekterna av ett “cirkulärt” kök från Chainable, ett företag i Nederländerna. Detta kök skiljer sig från andra vanliga kök eftersom det erbjuds som kök-som-en-service under en längre tid. Det följer cirkulära designstrategier som förlängning av livslängden, användning av återvunnet material, design för demontering och design för lätt konstruktion. Företaget underhåller köket och ser till att det är cirkulärt genom att antingen återvinna, återanvända eller återhämta avfallet i slutet av kökets livscykel. Detta kan eventuellt minska påverkan av byggandet av fler kök om människor och olika organisationer behåller dem på lång sikt.  Köket är tillverkat av olika komponenter som ram, paneler, handfat, kran, lådor, bänkskiva, handtag och eluttag. Kökets användningsfas inkluderar reparations- och underhållsscenarier för hela kökets livscykel.  Resultaten indikerar att produktionen och utbytet av spånskivor, tillverkningen av stålram och transporter kopplade till reparations- och underhållsscenarier har störst påverkan i kökets livscykel inom kategorierna klimatförändring och resursanvändning.

The mobile cooling and climate control industry provides a range of diverse solutions concerning the maintenance of temperature for comfortable living and safe transportation of goods over long distances. One of the major focuses of the industry is the transport sector for which products like cooling boxes and mobile air conditioners are exclusively designed for commercial and leisure purposes. However, the associated emissions released due to their use and the impact they have in the wake of the global climate crisis has led the industry to initiate activities and set targets to address this issue. This study aims to draw sustainable strategy recommendations to the mobile cooling and climate control industry by conducting a Life Cycle Assessment (LCA) of four products and a materiality assessment for a company manufacturing cooling boxes and mobile air conditioners, therefore accelerating the industry’s transition towards sustainability. The objectives are to identify potential material and process-related environmental hotspots over the life cycle of the products and carry out a materiality assessment that identifies topics of materiality for the company, this to outline strategies based on the results of both the LCA and the materiality assessment to improve the company’s sustainability in its operations. The results of the LCA highlighted the role of the use phase as one of the main contributors to the environmental impact from the use of cooling boxes and mobile air conditioners, while the manufacturing of the products and the end-of-life phase are shown to contribute also to the overall impact. Furthermore, different sensitivity scenarios revealed the potential that different materials, the use of batteries and the implementation of a take-back system have to decrease the environmental impacts of the products. From the materiality assessment fourteen material topics were identified to have significance and priority to the company. Based on these results, a total of nine strategies addressing the sustainability of the company and its products were outlined. Across the assessment, three key focus aspects were observed which can facilitate the sustainability transition of the company and industry: energy both in products and operations, collaboration with stakeholders, and circular economy principles and product innovation. Efforts within these areas can potentially improve the industry’s ability to tackle pressures from climate change and the increasing future demand. This study also exemplifies the potential benefits of a synergy between LCA and materiality assessment. It was observed that aiding the materiality assessment with the LCA results provides more tangibility to the results and decreases the subjectivity from the assessment in order to set future sustainability targets. / Mobilkylnings- och klimatkontrollsindustrin erbjuder många lösningar till temperaturhållning för bekvämt boende och säker transport av gods. Ett viktigt fokus för industrin är transportsektorn där produkter som kylboxar och mobil luftkonditionering specialkonstruerad för kommersiell och rekreationell användning. Växthusgasutsläppen från produkterna under användning har mot bakgrund av den globala klimatkrisen fått industrin att sätta mål och starta ett arbete för att minska utsläppen. Den här studien avser att ge hållbara strategier och rekommendationer till mobilkylnings- och klimatkontrollsindustrin genom att genomföra livscykelanalys (LCA) av fyra produkter och en materialanalys till ett företag som tillverkar kylboxar och mobila luftkonditioneringar för att driva industrins övergång till hållbarhet. Målen är att identifiera material- och processrelaterade miljöbelastningar över hela livscykeln av produkterna och genomföra en materialitetstsanalys för att identifiera materialitetsämnen. Utifrån LCA och materialitetsanalysen går att göra strategier att förbättra företagets hållbarhetsarbete. Resultat från LCAn visade vikten av användningsfasen som stod för den största miljöpåverkan från kylboxar or mobil luftkonditionering. Tillverkning och end-of-life hade också påverkan. Känslighetsanalyser visade också den potential materialval, batterianvändning och retursystem har att minska miljöpåverkan från produkter. Fjorton materialitetsämnen utpekades från materialitetsanalysen som viktiga för företaget. Dessa hanteras genom nio strategier som togs fram. Genom analys var tre övergripande fokusområden identifierade som kan underlätta företagets och industris hållbarhetsövergång. De är: energianvändning i både produkterna och företagets arbete, samarbeten med stakeholders samt cirkulär ekonomi och produktinnovation. Ansträngningar inom dessa områden kam förbättra industris förmåga att tackla trycket från klimatkrisen och ökad framtida efterfrågan. Studien visar också på synergin mellan LCA och materialitetsanalys. Att använda resultat från LCA i materialitetsanalysen gav tydligare resultat och minskar subjektiviteten vilket ger bättre förutsättningar när hållbarhetsmål ska sättas.

Dealerships are the main interface for customer interaction when it comes to a multinational manufacturing company like Volvo Group. A lot of studies in the field of environmental impact is done on different kind of buildings like office buildings, residential buildings, public buildings etc by performing Life Cycle Analysis (LCA), Life Cycle Cost analysis (LCC) etc. However, the number of studies done on an industrial building are very less when compared to other types of buildings. Industrial buildings are equally important in the construction industry since they play a good share in environmental impacts caused by buildings. The main objective of the thesis is to analyse the working process at VGRE and suggest ways to incorporate life cycle thinking in their working process to improve the environmental performance of new dealerships. Interviews were conducted with VGRE employees; literature reviews were done and analysis of internal documents from VGRE were studied and analysed as a part of the thesis. The views and opinions of the VGRE employees in the area of environment impact reduction, life cycle assessment and certification scheme/system were obtained and the steps involved in the development of a dealership as well as the different type of contract were also studied from the internal documents provided from VGRE. Cost was one of the main barrier/challenges in all the cases. Lack of interest in getting a dealership certified was also mentioned during the interviews. Energy saving measures like the solar panels were considered as additional cost for a building. Their preference in referring to previous Life Cycle studies of similar buildings rather than doing a Life cycle study on each building was also observed. / I syfte att identifiera hur man integrerar livscykeltänkande i arbetsprocessen hos Volvo Group Real Estate (VGRE) för att förbättra miljöprestanda för nya återförsäljare är detta examensarbete i princip en analys av arbetsprocessen hos Volvo som gjordes genom att göra intervjuer med Volvos anställda både i Göteborg, Sverige och Finland. Litteraturöversikter om livscykelanalys (LCA) samt certifieringssystem var också en del av metodiken. Slutligen analyserades och studerades några interna dokument från Volvo. LCA på Volvo, hinder och utmaningar som möter under arbetsprocessen, intern dokumentation, skillnaderna mellan en återförsäljare och andra byggnader, kostnadsfaktorer / affärssaker är de viktigaste slutsatserna som diskuteras i resultatsektionen.

Increased extreme weather events caused by climate change and other environmental impacts, are affecting already vulnerable people predominantly. These are populations with the least resilience to disasters. As a consequence, there is a higher demand for humanitarian aid which is expected to continuously increase in the face of anthropogenic emissions. Such growing need is in turn met by growing commitment from the humanitarian sector to ensure that aid is provided by means of environmentally sustainable practices. However, to what extent the current practices of humanitarian operations are impacting the environment is not well known as very little research has been conducted on environmental sustainability in this sector. As a step towards addressing this gap, this study takes on a mixed method approach to answer how to measure the environmental impacts and what they are. The sectors’ experience of practices on how to measure impacts are mapped out and a cradle-to- grave life cycle assessment in a humanitarian operation context is conducted. Studying one of the modular tools within response operations, Emergency Response Units (ERU) for water treatment, the study identifies and highlights the impact hotspots during the whole life cycle of one deployment. As a case study to carry this out, an ERU M40 from a Swedish Red Cross deployment in Uganda 2017 is reviewed. The study reveals hotspots in transportation of water distribution during the operational phase, international transport of the equipment and production of the material. It furthermore identifies challenges and opportunities of implementing such a tool in a new context in which only few similar studies have previously been conducted. Finally, this study contributes with recommendations based on empirical evidence for how an actor like the Swedish Red Cross can mitigate their environmental impacts by implementing a holistic life cycle approach and avoid causing unintended burdens. / Ökat extremväder orsakat av klimatförändringar och andra miljöpåverkan har som störst negativ effekt på redan utsatta människor. Det är befolkningar med minst resiliens mot katastrofer. Som en följd av detta uppstår en högre behov av humanitärt bistånd vilket förväntas ytterligare öka, på grund av antropogena utsläpp. Ett sådant växande behov möts av ett växande engagemang från humanitära sektorn för att säkerställa att stöd under dessa katastrofer ges genom miljömässigt hållbara metoder. I vilken utsträckning de nuvarande metoderna för humanitära insatser påverkar miljön är emellertid inte välkänt eftersom begränsad forskning har gjorts om hållbarhet utifrån ett miljöperspektiv i denna sektor. Som ett steg att minska den forskningsluckan använder denna studie en blandad metod för att svara på hur man mäter miljöpåverkan och vad den faktiska påverkan i dagsläget är. Erfarenheter inom humanitära sektorn av att applicera metoder för att mäta miljöpåverkan kartläggs och en vagga- till-graven livscykelanalys av en humanitärt insats genomförs. Studien utgår från ett modulärt verktyg inom humanitära instatser, ERU (Emergency Response Units) för vattenrening, och identifierar och belyser hotspots under livscykeln för en insats. Som en fallstudie för att genomföra detta har en ERU M40 från Svenska Röda korsets insats i Uganda 2017 använts. Studien påvisar hotspots för transport av vattendistribution under driftsfasen, internationell transport av modulen samt produktionen av materialet. Vidare identifieras utmaningar och möjligheter att implementera LCA i ett nytt sammanhang där endast ett fåtal liknande studier har genomförts tidigare. Slutligen bidrar denna studie med rekommendationer baserade på empiriska bevis för hur en aktör som Svenska Röda Korset kan minimera deras miljöpåverkan genom att implementera en holistisk livscykelperspektiv och undvika allokeringsproblem.

The construction sector has a large impact on the environment and is an industry where sustainable development is of importance moving forward. It requires large amount of materials, and is both waste and carbon intense. The greenhouse gas emissions from production in the construction industry was in 2017 estimated to 12,2 million tonne CO2-eq, representing 19% of the emissions in Sweden, and it has been estimated that infrastructure and foundations represents 60% of the emissions in the production phase. Since Sweden has the national objective of being climate neutral by the year 2045, climate calculations are of relevance for the sector in order to make more sustainable choices and increase the possibility to meet the target of becoming climate neutral. Atkins Sverige AB is a design and engineering consultant company mainly working with infrastructure who is currently in the process of choosing a software tool for climate calculations on the external consultant projects, and has therefore requested a comparison and evaluation of two simplified LCA- tools; Bidcon and Klimatkalkyl. The aim of this thesis was to provide a recommendation on which of these software Atkins Sverige should use for climate calculation on external consultant projects. This was conducted by assessing current industry praxis and comparing and evaluating the two software, both qualitatively and quantitatively. An evaluation of the tools was conducted by developing a framework for evaluation of simplified LCA-tools using an MCA approach, and both tools was applied to an existing project in a case study. The results from the case study indicate differences in emission factors between the software, where Klimatkalkyl had a result 21% lower than Bidcon, and there were large differences in potential impact between some of the resource categories in the two software. The largest difference in results was found for earthworks and demolition, with Klimatkalkyl having 220 and 111 tonne CO2-eq less than Bidcon in these resource categories, which represents 26% of the emissions in the Bidcon calculation. For Bidcon where more data was available, a second calculation was conducted, calculating the potential impact from the data which was not available in Klimatkalkyl. The results indicate that 38,6% of the total potential environmental impact of the project is excluded due to the lack of data in Klimatkalkyl. Out of the resources excluded from Klimatkalkyl, those with the highest potential impact was kerbstones, demolition, paving stones, filling around pipes, and wells. The evaluation framework had seven categories and the results indicated that three aspects were equal between the software; stakeholder acceptance, transparency and data quality, and informative. Klimatkalkyl received higher score in one category, life cycle perspective and environmental focus, while Bidcon received higher score in the remaining three categories; comprehensiveness of data, modification and user friendliness. Comprehensiveness is considered the most crucial category in the evaluation, and since the case study indicated 38,6% of emissions excluded from Klimatkalkyl, Bidcon is the recommended software for Atkins Sverige to use. Further, with Bidcon being more user friendly and offering more options for modification, it is considered easier to minimize errors in the calculations compared to Klimatkalkyl. / Byggindustrin har en stor miljöpåverkan och är en industri där hållbar utveckling är väsentligt framöver. Industrin kräver stora mängder råmaterial, och genererar stora mängder avfall och växthusgaser. Växthusgaserna från produktion inom byggindustrin var 2017 uppskattad till 12,2 miljoner ton CO2-eq, vilket motsvarar 19% av utsläppen i Sverige. Det har även uppskattats att 60% av utsläppen från produktionsfasen kommer från infrastruktur och anläggning. Då Sverige har miljömålet att vara klimatneutral 2045 är klimatberäkningar relevanta inom sektorn för att ta mer hållbara beslut och öka möjligheten att nå målet om att bli klimatneutral. Atkins Sverige AB är ett konsultföretag inom design och teknik, som främst arbetar med infrastrukturprojekt. De är nu i processen att välja ett verktyg för klimatberäkningar på sina externa konsultprojekt och har därför efterfrågat en utvärdering av två förenklade LCA-verktyg; Bidcon och Klimatkalkyl. Syftet med projektet var att rekommendera vilket av de här två verktygen Atkins Sverige bör använda i deras externa projekt. En rekommendation togs fram genom att kartlägga vad nuvarande praxis är gällande klimatberäkningar i industrin, samt jämföra och utvärdera verktygen både kvalitativt och kvantitativt. Ett ramverk för utvärdering av förenklade LCA-verktyg upprättades och följde en MCA-metod med sju kategorier, och båda verktygen tillämpades på ett befintligt projekt hos Atkins Sverige. Beräkningsresultaten på projektet visar på skillnader i emissionsfaktorer mellan verktygen, då Klimatkalkyl hade ett resultat 21% lägre än Bidcon. Det fanns stora skillnader i potentiell miljöpåverkan för flera resurskategorier. Störst skillnad fanns för schaktning och rivning, där Klimatkalkyl hade resultat 220 ton respektive 111 ton CO2-eq lägre än Bidcon, vilket motsvarar 26% av utsläppen i beräkningen i Bidcon. För Bidcon som hade en större databas än Klimatkalkyl genomfördes en andra beräkning för den data för projektet som inte fanns tillgänglig i Klimatkalkyl. Resultatet visar på att 38,6% av den totala potentiella miljöpåverkan i projektet utesluts på grund av saknad data i beräkningar i Klimatkalkyl. Av de resurskategorier som är uteslutna ur Klimatkalkyl är de med störst potentiell påverkan kantstenar, rivning, beläggning av sten, fyllning runt kablar och brunnar. Utvärderingen med ramverket visar på att tre av kategorierna var likvärdiga mellan verktygen; intressenters acceptans, transparens och datakvalitet och informativ. Klimatkalkyl fick bättre resultat i en kategori, livscykelperspektiv och miljöfokus, medan Bidcon fick bättre resultat i de tre resterande kategorierna; omfattning av data, modifiering och användarvänlighet. Dataomfattning anses vara den viktigaste kategorin i utvärderingen, och eftersom beräkningsresultaten visar på att 38,6% av utsläppen utesluts i beräkningar i Klimatkalkyl så är Atkins Sverige rekommenderade att investera i Bidcon. Då Bidcon även är mer användarvänligt och går att modifiera mer så anses det lättare att minimera fel i beräkningarna jämfört med Klimatkalkyl.

New windows are rated based on their energy performance during the use phase. This rating neglects the overall environmental impact caused by raw material extraction, manufacturing, maintenance and disposal. Due to the number of residential window replacements occurring today in the United States, there is a growing need to quantify the sustainability of window preservation as an alternative to window replacement. This study assessed the environmental impact of historic wood window restoration versus window replacement for the entire "cradle to grave" life cycle of the window assembly. This study focused on a typical, mid-twentieth century housing development in the Northeast United States using four window configurations as follows: 1. Restored original wood window with a new exterior aluminum storm window; 2. PVC replacement window; 3. Aluminum-clad wood replacement window; 4. Wood replacement window. The dissertation assessed the life cycle of window configurations using GaBi Software. The life cycle inventories were analyzed using the TRACI 2.1 impact method which translated the environmental consequences of the life cycle assessment processes into quantifiable environmental impacts. The dissertation also considered window thermal performance and life cycle costs. When considering life cycle environmental impacts, thermal performance, energy savings and material costs, the results indicated that wood window restoration was the best option when compared to replacement windows considered in this study; however, the results indicated that building service life and window service life assumptions could impact results. Thermal performance testing of windows revealed that window restoration techniques undertaken in this study improved the window's overall thermal performance. The testing also indicated that the effects of air infiltration had minimal influence on the performance of the restored window assembly when compared to a high performance replacement window. The results of the energy model exhibited only a small annual energy savings between the restored window assembly and a high performance replacement window. The payback cost analysis revealed that, while there was an immediate financial benefit of window replacement with the PVC option, window replacement frequency and overall life cycle environmental impacts would favor the restored window option. / Civil Engineering

Buildings account for up to a third of total world greenhouse gas GHG emissions, and this pattern is expected to persist. By 2050, cities will be home to 70 % of the world's population, demanding a significant number of buildings to be constructed. Efforts to reduce these emissions in the past had varied performance. However, several examples indicate that well thought and adequately executed mix of building technology coupled with environmental policies may reduce emissions. Therefore, cities worldwide are joining the race to decarbonize their buildings to become net-zero carbon and support green economies through a diversified bundle of policies. However, designing and selecting the appropriate mix of building technology and environmental policies is challenging to generate the most outlast net-zero carbon impacts. This research aims to uncover the intersection between science and policy's role in achieving a global net-zero energy building sector. First, an urban comparative analysis for ten environment-leading cities has been made to understand the latest progress in the building sector and draw on future recommendations. The findings are thematically grouped into five themes a) Building's energy efficiency (energy demand sector). (b) Electrified renewable grids (energy supply sector). (c) Green fiscal incentives (d) Education and capacity building. (e) Governance and collaboration. Second, the University of Ottawa has been utilized as a part of the campus as a living lab initiative to examine installing photovoltaic panels over the campus buildings as part of the university expansion program to achieve net-zero operations by 2040. The following parameters have been considered to address the PV systems viability, 1) the expected electricity output. 2) the initial and operational costs. 3) the GHG reductions in operational energy. 4) the PV system embodied carbons. RETScreen Expert software has been used to perform the Life Cycle Cost Analysis (LCCA) to assess PV system output and financial viability. One Click-LCA software to carry-out Life Cycle Assessment (LCA) to assess embodied carbons. The results indicate from analyzing 31 buildings that 20% - 107% of electricity can be offset depending on each building's energy use and solar collector area. Additionally, the 31 buildings analyzed for electricity generation collectively have the potential to save around 23% of the total campus electricity consumption with a production capacity of 18 million units (kWh) annually, including 21,108 solar panels. Also, the project shows financial viability only if the PV systems are installed as part of the whole campus with a Net Present Value (NPV) of $4,985,89 and an Internal Rate of Return (IRR) of 11.4%. The analysis shows 24% and 18% maximum sensitivity to increased initial cost and decreased electricity generation/rate. Finally, the GHG estimated reductions over 25 years from generated electricity are 14,445 tCO2, and the estimated increased embodied carbons from the Life Cycle Assessment are set to be 1,023 tCO2. Additionally, drawing upon urban analysis and the case study, the research highlights the dynamic nature of the building sector emissions reduction and city initiatives. Thirdly, a detailed analysis was carried out in the System Advisor Model (SAM) software to integrate the solar system with energy storage in the Advanced Research Complex (ARC) Building at the University of Ottawa. The study assesses the system viability and helps the university to reduce its monthly electricity bill and help Ontario to maintain its grid reliability by keeping the electricity demand low at peak times. The findings show that using an integrated solar system with an energy storage system by mitigating 100%, 90%, 75%, and 50% of the building electricity demand during the Ontario gird peak could lead to a Net Present Value of $2,01, $1.70, $1.30, and $0.864 million over 25 years the lifetime of the project through the Ontario Global Adjustment Program. The study also shows that with the absence of the Ontario Global Adjustment Program as a fiscal reform tool and relying only on the time of use electricity rates, the solar panels with an energy storage system could lead to a negative Net Present Value of $-550 thousand.

Yes / Developing a fast, cost-effective, eco-friendly solution to recycle large amounts of construction and demolition waste (CDW) generated from construction industry-related activities and natural disasters is crucial. The present investigation aims to offer a solution for repurposing CDW into building materials suitable for accelerated construction and housing in developing countries and disaster-prone areas. Feasibility of recycled concrete aggregate (RCA) inclusion in geopolymer mortars constituted entirely from CDW (masonry elements) was investigated via an environmental impact-oriented approach by addressing the composition related key parameters. Mechanical performance was evaluated through compressive strength tests, and scanning electron microscope (SEM) imaging with line mapping analyses were carried out to monitor the interfacial transition zone (ITZ) properties. To investigate the environmental impacts of the geopolymer mortars and highlight the advantages over Portland cement-based mortars, a cradle-to-gate life cycle assessment (LCA) was performed. Findings revealed that roof tile (RT)-based geopolymer mortars mainly exhibited better strength performance due to their finer particle size. Mixtures activated with 15 M NaOH solution and cured at 105 °C achieved an average compressive strength above 55 MPa. RCA size was the most influential parameter on compressive strength, and a smaller maximum RCA size significantly increased the compressive strength. Microstructural analyses showed that the ITZ around smaller RCAs was relatively thinner, resulting in better compressive strength results. LCA proved that CDW-based geopolymer mortars provide the same compressive strength with around 60% less CO2 emissions and similar energy consumption compared to Portland cement-based mortars. / This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 894100. The authors also wish to acknowledge the support of the Scientific and Technical Research Council of Turkey (TUBITAK) provided under project: 117M447