Decision-making tool for the optimal selection of a domestic water-heating system considering economic, environmental and social criteria: application to Barcelona (Spain)

The research presented in this paper has two main objectives. First, it aims to generate an assessment tool for ranking and selecting the most sustainable domestic water-heating system (WHS) (with the lowest economic, environmental and social impact) that could be applied in any location and with any demand. Second, it aims to ascertain which WHS is the most sustainable in places with a climate and solar radiation like that of Barcelona, Spain, where a minimum solar contribution to domestic water heating is compulsory for new buildings and significant renovations. Multi-criteria decision analysis was employed to create the optimised flexible assessment tool. The Delphi method was followed to perform the surveys, and to provide the objectivity required in the identification of impacts, the definition of indicators and the assignment of weights. The most relevant criteria were determined: annual cost, material consumption, energy consumption, GHG emissions, space requirement, visual impact and occupational risks. The resulting tool was tested by analysing twelve domestic WHS, including two conventional systems, and ten combinations of five solar thermal technologies with two conventional systems as backup for a changing room in a sport centre located in Barcelona. The two conventional WHS studied were a natural gas-fired condensing boiler and an electric water heater. The five solar thermal technologies were: a flat plate with a harp design, a flat plate with a serpentine design, a heat-pipe evacuated tube, a direct-flow evacuated tube, and a direct-flow evacuated tube with CPC. The dynamic thermal simulation programme T*SOL was used to dimension the solar thermal systems. Two sensitivity analyses were carried out: one on weights and one on references. The tool proved very useful in the assessment of these systems, and could also help in decision-making processes to select the most sustainable WHS for other locations and domestic hot water demands.Peer ReviewedPostprint (author's final draft

MetodologÍa para la evaluación y seguimiento de procedimientos constructivos de forma sostenible e integrada

This doctoral thesis defines a new methodology for evaluating and comparing different construction projects in an objective and systematic manner. It is innovative by incorporating issues as diverse as cost, occupational risks, environmental impact, and social impact. The methodology enables public administrations or other entities, during the construction tender stage, to quantify and compare the impact of the different construction options, to prioritise them, and to select the best based on a multi-criteria analysis. The proposed methodology can assess the impact of actual work during construction and contrast it with the impact predicted at the design stage, enabling corrective measures to be proposed timeously. The methodology is based on the multi-attribute utility theory, which was found to be the most appropriate theory among all multi-criteria decision aid methods reviewed. An occupational risk index (ORI) that allows the quantification of occupational risks in construction work is defined. The ORI is based solely on a given project's design and its resulting construction process and a project's ORI is a function of the total amount of work to be devoted to each risk activity. Occupational risks in construction work - and the activities in which the risks are present - have been categorised and, for each risk activity, the probability of occurrence and the most probable consequence have been determined. The ORI allows the prioritisation of the construction processes in terms of occupational risks and the selection of the least occupationally-risky construction process. It also enables the detection of the most risky activities and the introduction of improvements. Prior to the ORI, no similar index specific to construction work existed. A construction project has environmental impacts not only during the construction work stage but also during the preceding stages (extraction, manufacturing and transport of construction materials). The environmental impacts of the different stages in construction projects have been studied and different ways for measuring them have been defined according to data availability. The thesis includes average values of energy consumption and greenhouse gas emissions obtained from databases and from calculations in the thesis. This data can be used for the environmental impact calculations in cases where more accurate local data is not available. The methodology is sensitive to material consumption, reuse and recycling, energy saving, greenhouse gas and air pollutant emissions, waste generation, effects on sensitive environments and suchlike. The methodology enables the prioritisation of the construction projects, the selection of the best alternative and the introduction of improvements in terms of environmental impact. Social impacts due to construction work, especially in urban areas, (effects on transport, pedestrians, shops, noise and others) are very complex to analyse and the hitherto least studied and regulated type of impact. The different types of social impacts produced during construction work are identified and classified. An objective and systematic manner of measuring each one of these impacts is defined. The ability to quantify these social impacts is considered to be one of the main innovations of the thesis. This enables the prioritisation of the construction projects, the selection of the best alternative and the introduction of improvements in terms of social impact. Another significant contribution of the methodology is the incorporation of the different types of impacts, including the cost, in the same evaluation. Furthermore, it enables the incorporation of the interests of the different stakeholders: developers, people affected during construction work, constructors, etc. The methodology has been successfully applied in field trials: to four construction projects built by Imperial College London students in the UK and to two emergency shafts of a tunnel in Barcelona.En la present tesi doctoral es defineix una metodologia que permet avaluar i comparar de forma objectiva i sistematitzada diferents procediments constructius integrant aspectes tan diversos com el cost, els riscos laborals, l'impacte ambiental i l'impacte social. La metodologia permet, a l'administració o qualsevol altra entitat, en la fase de licitació d'una obra, quantificar i comparar l'impacte de les diferents alternatives presentades a concurs, prioritzar-les i elegir la millor des d'un punt de vista multicriteri. També permet, en la fase d'execució d'una obra, avaluar i comparar l'impacte de l'obra planificada al projecte amb l'impacte de l'obra que s'està executant i sol¿licitar correccions o mesures compensatòries equivalents en cas de desviament. La metodologia s'estructura a partir de la teoria d'utilitat multiatribut, considerada com la més adequada entre tots els mètodes d'ajuda a la decisió estudiats. Primerament, s'ha definit un Índex de Risc Laboral (IRL) que permet quantificar els riscos laborals dels procediments constructius. L'IRL depèn de les hores de treball dedicades a cada activitat amb risc i, per tant, es pot calcular a partir de les dades de projecte. Per desenvolupar l'índex s'han tipificat els riscos laborals de la construcció i les activitats en les que hi són presents i, per a cada activitat amb risc, s'ha definit la probabilitat d'ocurrència i la conseqüència més probable en cas de produir-se l'accident. L'IRL permet prioritzar els procediments constructius respecte als riscos laborals i elegir el que impliqui menys riscos per als treballadors. També permet detectar les activitats amb més risc i introduir millores. Anteriorment no existia un índex similar específic de la construcció. L'impacte ambiental d'un procediment constructiu no es produeix només durant la fase d'execució sinó que es produeix també en les fases anteriors (extracció, manufactura i transport dels materials de construcció). En la tesi s'han estudiat els impactes ambientals i les fases en que es produeixen i s'han definit diferents formes de mesurar-los en funció de les dades disponibles. S'inclouen valors promitjos de consums d'energia i emissions de gasos d'efecte hivernacle obtinguts de bases de dades i de càlculs realitzats a la tesi. Aquestes dades es poden utilitzar per al càlcul de l'impacte en cas de no disposar d'informació més precisa. La metodologia és sensible al consum de materials, la reutilització i el reciclatge, l'estalvi energètic, l'emissió de gasos d'efecte hivernacle i contaminants atmosfèrics, la generació de residus, l'afecció a entorns sensibles, etc. La metodologia permet prioritzar els procediments constructius respecte a l'impacte ambiental, elegir el millor i introduir millores. Els impactes socials produïts per una obra, especialment en zona urbana, (afecció al transport, vianants, comerços, soroll, etc.) són els més complexos d'analitzar i els menys regulats i estudiats fins al moment. En la tesi s'identifiquen i es tipifiquen els diferents impactes socials produïts per l'execució d'una obra i es defineix la forma de mesurar cadascun d'aquests impactes de manera objectiva i sistematitzada. La possibilitat de quantificar l'impacte social es considera una de les principals aportacions de la tesi. Això permet prioritzar els diferents procediments constructius respecte a l'impacte social, elegir el millor i introduir millores. Una altra aportació important de la metodologia és que permet integrar els diferents impactes, juntament amb el cost, dins d'una mateixa avaluació. També permet integrar els interessos de les diferents parts implicades: administració, persones afectades durant l'obra, constructores, etc. La metodologia s'ha aplicat amb èxit a quatre projectes constructius executats per estudiants de l'Imperial College London al Regne Unit i a les obres de dos pous de ventilació i sortida d'emergència d'un túnel a Barcelona. Les aplicacions pràctiques han permès ajustar i millorar la metodologia.En la presente tesis doctoral se define una metodología que permite evaluar y comparar de forma objetiva y sistematizada distintos procedimientos constructivos integrando aspectos tan diversos como el coste, los riesgos laborales, el impacto ambiental y el impacto social. La metodología permite, a la administración o cualquier otra entidad, en la fase de licitación de una obra, cuantificar y comparar el impacto de las distintas alternativas presentadas a concurso, priorizarlas y elegir la mejor desde un punto de vista multicriterio. También permite, en la fase de ejecución de una obra, evaluar y comparar el impacto de la obra planificada en proyecto con el impacto de la obra que se está ejecutando y solicitar correcciones o medidas compensatorias equivalentes en caso de desvío. La metodología se estructura a partir de la teoría de utilidad multiatributo, considerada como la más adecuada de entre todos los métodos de ayuda a la decisión estudiados. En primer lugar se ha definido un Índice de Riesgo Laboral (IRL) que permite cuantificar los riesgos laborales de los procedimientos constructivos. El IRL depende de las horas de trabajo dedicadas a cada actividad con riesgo y, por tanto, se puede calcular a partir de los datos de proyecto. Para desarrollar el índice, se han tipificado los riesgos laborales de la construcción y las actividades en las que están presentes y, para cada actividad con riesgo, se ha definido la probabilidad de ocurrencia y la consecuencia más probable en caso de producirse el accidente. El IRL permite priorizar los procedimientos constructivos respecto a los riesgos laborales y elegir el que implique menos riesgos para los trabajadores. También permite detectar las actividades con más riesgo e introducir mejoras. Anteriormente no existía ningún índice similar específico de la construcción. El impacto ambiental de un procedimiento constructivo no se produce únicamente durante la fase de ejecución de una obra sino que también se produce en las fases anteriores (extracción, manufactura y transporte de los materiales de construcción). En la tesis se han estudiado los impactos ambientales y las fases en las que se producen y se han definido distintas formas de medirlos en función de los datos disponibles. Se incluyen valores promedios de consumos de energía y emisiones de gases de efecto invernadero obtenidos de bases de datos y cálculos realizados en la tesis. Estos datos se pueden utilizar para el cálculo del impacto en caso de no disponer de información más precisa. La metodología es sensible al consumo de materiales, reutilización y reciclaje, ahorro energético, emisión de gases de efecto invernadero y contaminantes atmosféricos, generación de residuos, afección a entornos sensibles, etc. La metodología permite priorizar los procedimientos constructivos respecto al impacto ambiental, elegir el mejor e introducir mejoras. Los impactos sociales producidos por una obra, especialmente en zona urbana, (afección al transporte, peatones, comercios, ruido, etc.) son los más complejos de analizar y los menos regulados y estudiados hasta el momento. En la tesis se identifican y tipifican los distintos impactos sociales producidos por la ejecución de las obras y se define la forma de medir cada uno de ellos de manera objetiva y sistematizada. La posibilidad de cuantificar el impacto social se considera una de las principales innovaciones de la tesis, lo que permite priorizar los distintos mejoras. Otra aportación importante de la metodología es que permite integrar los distintos impactos, junto al coste, en una misma evaluación. También permite integrar los intereses de las distintas partes implicadas: administración, personas afectadas durante la obra, constructoras, etc. La metodología se ha aplicado con éxito a cuatro proyectos constructivos ejecutados por estudiantes del Imperial College London en el Reino Unido y a las obras de dos pozos de ventilación y salida de emergencia de un túnel a Barcelona. Las aplicaciones prácticas han permitido ajustar y mejorar la metodología. Con estos datos se ha realizado un análisis de sensibilidad de los resultados a la variación de los pesos concluyéndose que los resultados y la metodología son muy estables. Las aplicaciones prácticas y el análisis de sensibilidad validan la metodología. La metodología es flexible, fácilmente aplicable y se puede adaptar a cualquier tipo de obra (desde la más sencilla hasta la más compleja), en cualquier entorno (urbano, periurbano y rural) y en las diferentes fases de un proyecto (diseño, licitación y ejecución de obra). La metodología desarrollada está basada en el análisis de más de 150 legislaciones europeas y españolas sobre prevención de riesgos laborales, impacto ambiental e impacto social relacionadas con el sector de la construcción, en la revisión de más de 240 publicaciones científicas y técnicas y en la realización de entrevistas a más de 30 expertos en los distintos ámbitos que abarca la metodología.Postprint (published version

MetodologÍa para la evaluación y seguimiento de procedimientos constructivos de forma sostenible e integrada

This doctoral thesis defines a new methodology for evaluating and comparing different construction projects in an objective and systematic manner. It is innovative by incorporating issues as diverse as cost, occupational risks, environmental impact, and social impact. The methodology enables public administrations or other entities, during the construction tender stage, to quantify and compare the impact of the different construction options, to prioritise them, and to select the best based on a multi-criteria analysis. The proposed methodology can assess the impact of actual work during construction and contrast it with the impact predicted at the design stage, enabling corrective measures to be proposed timeously. The methodology is based on the multi-attribute utility theory, which was found to be the most appropriate theory among all multi-criteria decision aid methods reviewed. An occupational risk index (ORI) that allows the quantification of occupational risks in construction work is defined. The ORI is based solely on a given project's design and its resulting construction process and a project's ORI is a function of the total amount of work to be devoted to each risk activity. Occupational risks in construction work - and the activities in which the risks are present - have been categorised and, for each risk activity, the probability of occurrence and the most probable consequence have been determined. The ORI allows the prioritisation of the construction processes in terms of occupational risks and the selection of the least occupationally-risky construction process. It also enables the detection of the most risky activities and the introduction of improvements. Prior to the ORI, no similar index specific to construction work existed. A construction project has environmental impacts not only during the construction work stage but also during the preceding stages (extraction, manufacturing and transport of construction materials). The environmental impacts of the different stages in construction projects have been studied and different ways for measuring them have been defined according to data availability. The thesis includes average values of energy consumption and greenhouse gas emissions obtained from databases and from calculations in the thesis. This data can be used for the environmental impact calculations in cases where more accurate local data is not available. The methodology is sensitive to material consumption, reuse and recycling, energy saving, greenhouse gas and air pollutant emissions, waste generation, effects on sensitive environments and suchlike. The methodology enables the prioritisation of the construction projects, the selection of the best alternative and the introduction of improvements in terms of environmental impact. Social impacts due to construction work, especially in urban areas, (effects on transport, pedestrians, shops, noise and others) are very complex to analyse and the hitherto least studied and regulated type of impact. The different types of social impacts produced during construction work are identified and classified. An objective and systematic manner of measuring each one of these impacts is defined. The ability to quantify these social impacts is considered to be one of the main innovations of the thesis. This enables the prioritisation of the construction projects, the selection of the best alternative and the introduction of improvements in terms of social impact. Another significant contribution of the methodology is the incorporation of the different types of impacts, including the cost, in the same evaluation. Furthermore, it enables the incorporation of the interests of the different stakeholders: developers, people affected during construction work, constructors, etc. The methodology has been successfully applied in field trials: to four construction projects built by Imperial College London students in the UK and to two emergency shafts of a tunnel in Barcelona.En la present tesi doctoral es defineix una metodologia que permet avaluar i comparar de forma objectiva i sistematitzada diferents procediments constructius integrant aspectes tan diversos com el cost, els riscos laborals, l'impacte ambiental i l'impacte social. La metodologia permet, a l'administració o qualsevol altra entitat, en la fase de licitació d'una obra, quantificar i comparar l'impacte de les diferents alternatives presentades a concurs, prioritzar-les i elegir la millor des d'un punt de vista multicriteri. També permet, en la fase d'execució d'una obra, avaluar i comparar l'impacte de l'obra planificada al projecte amb l'impacte de l'obra que s'està executant i sol¿licitar correccions o mesures compensatòries equivalents en cas de desviament. La metodologia s'estructura a partir de la teoria d'utilitat multiatribut, considerada com la més adequada entre tots els mètodes d'ajuda a la decisió estudiats. Primerament, s'ha definit un Índex de Risc Laboral (IRL) que permet quantificar els riscos laborals dels procediments constructius. L'IRL depèn de les hores de treball dedicades a cada activitat amb risc i, per tant, es pot calcular a partir de les dades de projecte. Per desenvolupar l'índex s'han tipificat els riscos laborals de la construcció i les activitats en les que hi són presents i, per a cada activitat amb risc, s'ha definit la probabilitat d'ocurrència i la conseqüència més probable en cas de produir-se l'accident. L'IRL permet prioritzar els procediments constructius respecte als riscos laborals i elegir el que impliqui menys riscos per als treballadors. També permet detectar les activitats amb més risc i introduir millores. Anteriorment no existia un índex similar específic de la construcció. L'impacte ambiental d'un procediment constructiu no es produeix només durant la fase d'execució sinó que es produeix també en les fases anteriors (extracció, manufactura i transport dels materials de construcció). En la tesi s'han estudiat els impactes ambientals i les fases en que es produeixen i s'han definit diferents formes de mesurar-los en funció de les dades disponibles. S'inclouen valors promitjos de consums d'energia i emissions de gasos d'efecte hivernacle obtinguts de bases de dades i de càlculs realitzats a la tesi. Aquestes dades es poden utilitzar per al càlcul de l'impacte en cas de no disposar d'informació més precisa. La metodologia és sensible al consum de materials, la reutilització i el reciclatge, l'estalvi energètic, l'emissió de gasos d'efecte hivernacle i contaminants atmosfèrics, la generació de residus, l'afecció a entorns sensibles, etc. La metodologia permet prioritzar els procediments constructius respecte a l'impacte ambiental, elegir el millor i introduir millores. Els impactes socials produïts per una obra, especialment en zona urbana, (afecció al transport, vianants, comerços, soroll, etc.) són els més complexos d'analitzar i els menys regulats i estudiats fins al moment. En la tesi s'identifiquen i es tipifiquen els diferents impactes socials produïts per l'execució d'una obra i es defineix la forma de mesurar cadascun d'aquests impactes de manera objectiva i sistematitzada. La possibilitat de quantificar l'impacte social es considera una de les principals aportacions de la tesi. Això permet prioritzar els diferents procediments constructius respecte a l'impacte social, elegir el millor i introduir millores. Una altra aportació important de la metodologia és que permet integrar els diferents impactes, juntament amb el cost, dins d'una mateixa avaluació. També permet integrar els interessos de les diferents parts implicades: administració, persones afectades durant l'obra, constructores, etc. La metodologia s'ha aplicat amb èxit a quatre projectes constructius executats per estudiants de l'Imperial College London al Regne Unit i a les obres de dos pous de ventilació i sortida d'emergència d'un túnel a Barcelona. Les aplicacions pràctiques han permès ajustar i millorar la metodologia.En la presente tesis doctoral se define una metodología que permite evaluar y comparar de forma objetiva y sistematizada distintos procedimientos constructivos integrando aspectos tan diversos como el coste, los riesgos laborales, el impacto ambiental y el impacto social. La metodología permite, a la administración o cualquier otra entidad, en la fase de licitación de una obra, cuantificar y comparar el impacto de las distintas alternativas presentadas a concurso, priorizarlas y elegir la mejor desde un punto de vista multicriterio. También permite, en la fase de ejecución de una obra, evaluar y comparar el impacto de la obra planificada en proyecto con el impacto de la obra que se está ejecutando y solicitar correcciones o medidas compensatorias equivalentes en caso de desvío. La metodología se estructura a partir de la teoría de utilidad multiatributo, considerada como la más adecuada de entre todos los métodos de ayuda a la decisión estudiados. En primer lugar se ha definido un Índice de Riesgo Laboral (IRL) que permite cuantificar los riesgos laborales de los procedimientos constructivos. El IRL depende de las horas de trabajo dedicadas a cada actividad con riesgo y, por tanto, se puede calcular a partir de los datos de proyecto. Para desarrollar el índice, se han tipificado los riesgos laborales de la construcción y las actividades en las que están presentes y, para cada actividad con riesgo, se ha definido la probabilidad de ocurrencia y la consecuencia más probable en caso de producirse el accidente. El IRL permite priorizar los procedimientos constructivos respecto a los riesgos laborales y elegir el que implique menos riesgos para los trabajadores. También permite detectar las actividades con más riesgo e introducir mejoras. Anteriormente no existía ningún índice similar específico de la construcción. El impacto ambiental de un procedimiento constructivo no se produce únicamente durante la fase de ejecución de una obra sino que también se produce en las fases anteriores (extracción, manufactura y transporte de los materiales de construcción). En la tesis se han estudiado los impactos ambientales y las fases en las que se producen y se han definido distintas formas de medirlos en función de los datos disponibles. Se incluyen valores promedios de consumos de energía y emisiones de gases de efecto invernadero obtenidos de bases de datos y cálculos realizados en la tesis. Estos datos se pueden utilizar para el cálculo del impacto en caso de no disponer de información más precisa. La metodología es sensible al consumo de materiales, reutilización y reciclaje, ahorro energético, emisión de gases de efecto invernadero y contaminantes atmosféricos, generación de residuos, afección a entornos sensibles, etc. La metodología permite priorizar los procedimientos constructivos respecto al impacto ambiental, elegir el mejor e introducir mejoras. Los impactos sociales producidos por una obra, especialmente en zona urbana, (afección al transporte, peatones, comercios, ruido, etc.) son los más complejos de analizar y los menos regulados y estudiados hasta el momento. En la tesis se identifican y tipifican los distintos impactos sociales producidos por la ejecución de las obras y se define la forma de medir cada uno de ellos de manera objetiva y sistematizada. La posibilidad de cuantificar el impacto social se considera una de las principales innovaciones de la tesis, lo que permite priorizar los distintos mejoras. Otra aportación importante de la metodología es que permite integrar los distintos impactos, junto al coste, en una misma evaluación. También permite integrar los intereses de las distintas partes implicadas: administración, personas afectadas durante la obra, constructoras, etc. La metodología se ha aplicado con éxito a cuatro proyectos constructivos ejecutados por estudiantes del Imperial College London en el Reino Unido y a las obras de dos pozos de ventilación y salida de emergencia de un túnel a Barcelona. Las aplicaciones prácticas han permitido ajustar y mejorar la metodología. Con estos datos se ha realizado un análisis de sensibilidad de los resultados a la variación de los pesos concluyéndose que los resultados y la metodología son muy estables. Las aplicaciones prácticas y el análisis de sensibilidad validan la metodología. La metodología es flexible, fácilmente aplicable y se puede adaptar a cualquier tipo de obra (desde la más sencilla hasta la más compleja), en cualquier entorno (urbano, periurbano y rural) y en las diferentes fases de un proyecto (diseño, licitación y ejecución de obra). La metodología desarrollada está basada en el análisis de más de 150 legislaciones europeas y españolas sobre prevención de riesgos laborales, impacto ambiental e impacto social relacionadas con el sector de la construcción, en la revisión de más de 240 publicaciones científicas y técnicas y en la realización de entrevistas a más de 30 expertos en los distintos ámbitos que abarca la metodología

Decision-making tool for the assessment and selection of construction processes based on environmental criteria: Application to precast and cast-in-situ alternatives

This paper presents a quantitative environmental impact assessment tool for the decision making of construction processes including structures, infrastructures and buildings by means of an Environmental Impact Index (EII) to be applied at design and/or construction stages. The research is based on multi-attribute utility theory, interviews with experts representatives of the different stakeholders in construction, and an analysis of fifty-nine European and Spanish environmental legislative acts. The resulting tool was applied to two construction alternatives for road drains (one precast and one cast-in-place). The findings show that the tool enables the prioritisation of construction processes and the selection of the best alternative in terms of environmental impact and that the results are stable to reasonable weight variations. The tool contributes to decision making in the context of project management in construction: it can help professionals in public administration, and design and construction companies. It helps to quantify the cradle-to-gate impact of construction work, which has usually been less studied than the operational impact in the life-cycle assessment of buildings. The tool is being piloted in construction projects of the Barcelona City Council.Peer ReviewedPostprint (author's final draft

Decision-making tool for enhancing the sustainable management of cultural institutions: Season content programming at Palau De La Musica Catalana

There has been an increasing relevance of the cultural sector in the economic and social development of different countries. However, this sector continues without much input from multi-criteria decision-making (MDCM) techniques and sustainability analysis, which are widely used in other sectors. This paper proposes an MCDM model to assess the sustainability of a musical institution’s program. To define the parameters of the proposed model, qualitative interviews with relevant representatives of Catalan cultural institutions and highly recognized professionals in the sector were performed. The content of the 2015–2016 season of the ‘Palau de la Música Catalana’, a relevant Catalan musical institution located in Barcelona, was used as a case study to empirically test the method. The method allows the calculation of a season value index (SVI), which serves to make more sustainable decisions on musical season programs according to the established criteria. The sensitivity analysis carried out for different scenarios shows the robustness of the method. The research suggests that more complex decision settings, such as MCDM methods that are widely used in other sectors, can be easily applied to the sustainable management of any type of cultural institution. To the best of the authors’ knowledge, this method was never applied to a cultural institution and with real data.Peer ReviewedPostprint (published version

The multi-criteria assessment of sustainable residential high-rise building design

Habitation is the basis of social-cultural and economic context and it is an essential factor in the life quality for residents. Sustainable development (SD) is a comprehensive concept and includes all social, environmental and economic aspects. The concept of SD is a significant challenge in determining the relationship between environment and humans, and humans with each other. The dimension of sustainable social development has still been scarcely researched. In recent decades, the construction of high-rise residential buildings (HRB) is increasing aiming at solving several housing problems. Initially, HRB were meant to optimize the land’s use in mega cities’ centres but, gradually, as the cities were developing, the need to construct HRB in urban areas has increased. The advantages and disadvantages as well as the problems of this type of buildings are exposed along with some initial conclusions about construction of HRBs. The main objective of this research is to develop a multi-criteria decision making (MCDM) tool for assessing sustainability using the Integrated Value Model for Sustainability Assessment (MIVES).The MIVES approach reduces the subjectivity in decision-making, while integrating economic, environmental and social factors. In this research, a new evaluation model that examines the sustainability parameters in the design of residential high-rise buildings is presented. The first findings seem to prove that the design of HRB and collective habitats require physical, social, economic, and environmental aspects to be taken into account to maximize the satisfaction of all the involved stakeholders. This is the first research to examine the sustainability of residential high-rise buildings using the Integrated Value Model for Sustainable Assessment (MIVES) as a multi-criteria decision-making approach.Postprint (published version

Multi-criteria decision making in the social sustainability assessment of high-rise residential buildings

Factors such as global urbanization, scarcity of land, and rising land prices will increase the need for high-rise buildings. Population growth has led to dense life in residential high-rise buildings (RHRB). On the one hand, RHRB have benefits such as the maximization of land use. On the other hand, disadvantages such as ignoring features of cultural context, difficulties in guaranteeing natural ventilation and the high maintenance expenses are considered as their weaknesses. According to previous studies, most current RHRB do not consider social cohesion and local identity. Studies have proven that dimensions of social sustainability have been scarcely considered. The main objective in sustainability assessment of RHRB consist in reducing the environmental impact and increasing the efficiency and residents' satisfaction. Recent studies have considered modern methods for assessing the sustainability; in this regard, multi-criteria decision-making (MCDM) approaches are one of the most common alternatives to assess sustainability. The aim of this research is to develop a MCDM tool oriented to specifically assessing sustainability by using the Integrated Value Model for Sustainability Assessment (MIVES). The MIVES approach allows minimizing subjectivity in decision making while objectively integrating economic, environmental and social factors. In this paper, a new sustainability assessment model, which has been specifically configured to analyse social parameters for high-rise residential buildings, is presented. The findings show that most of the RHRB aspects positively affect the characteristics of the buildings and surroundings, while also affecting the psychological needs of humans.Postprint (published version

Optimisation of post-disaster assisted self-build housing construction and labour safety in developing countries

Natural and man-made disasters and conflicts occur constantly around the world, leaving displaced and vulnerable people every year, especially in the developing countries. Among other urgent necessities, this population needs to rebuild their houses. Due to the scarcity of resources in these disaster contexts, many of them opt for self-build or community-based construction of simple houses. Community-based construction can be a solution in these situations, maybe the only one available, but arises other problems such as a scarce awareness and prevention of the labour risks and scarce construction knowledge and skills. Taking into account all the factors, a possible solution to this, proposed by the authors, could be an ‘assisted self-build construction’. That is to say, a self-construction by a community, in which the members have been specifically trained in the labour risk prevention and construction materials and techniques they are going to use. This involve a previous analysis with the following steps: (1) study of the local and traditional materials and construction techniques of vernacular houses; (2) study of how they could be improved by incorporating new current construction knowledge; (3) design of different low-tech but high-knowledge housing appropriate for self-building; (4) evaluation of the sustainability of the alternative designs, including the labour risks during construction, and selection of the best one; and (5) definition of the teaching content and plan. The selected design should integrate the local and traditional construction materials and knowledge, which are usually available and sustainable, with the current knowledge, in order to improve the traditional design and make it more resistant to natural hazards such as earthquakes and, at the same time, create a more comfortable house. The labour risks during self-construction should be evaluated, the construction process adapted in order to minimise the risks, and preventive measure defined.Postprint (published version

Environmental and economic impacts of combining backfill materials for novel circular narrow trenches

Over the last few years, several policies and new technological solutions have targeted the construction sector with the aim of reducing the sector's impacts on the environment. Among the different technological advances proposed, the reuse of materials in construction has been reported as a promising solution for an increase in sustainability and circularity. In particular, a type of cities' undergrounds assets for which materials' reuse is being explored are trenches for protecting services (i.e., water and gas transport pipelines, and optic fibre and other telecommunications services). Nonetheless, the economic and environmental benefits and impact of this type of system is still insufficiently quantified. In this research study, the economic and environmental impacts of four scenarios of trenches were assessed by using Life Cycle Costing (LCC) and Life Cycle Assessment (LCA). The four alternatives analysed consisted of: (1) the classical solution; (2) the classical solution with the reuse of soil; (3) the control low-strength material, and (4) the eco-trench. The results allowed concluding that in the eco-trench system, for which all material is reused, the environmental and economic impacts could be reduced by more than 80% and 50%, respectively. A parametric study for which the dimensions of the trenches were varied, permitted to reinforce these results and to quantify the impact's change along with the width and depth of the trench. Overall, this study provides a comprehensive view of the high-impact potential of reusing material for the construction of trenches in cities. The outcomes allow also remarking that the eco-trench system could be an attractive and advantageous solution for urban infrastructure stakeholders, both from an economic and environmental perspective.Peer ReviewedObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats SosteniblesObjectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles::11.6 - Per a 2030, reduir l’impacte ambiental negatiu per capita de les ciutats, amb especial atenció a la qualitat de l’aire, així com a la gestió dels residus municipals i d’altre tipusPostprint (published version

Flexural strength of high-performance soil-cement: a new, alternative, sustainable construction material

Soil-cement is a building material that is considered low-cost and has a low environmental impact. Despite its benefits, performance optimisation studies are scarce compared to other materials such as concrete. The possibility of obtaining soil-cement with improved characteristics, such as flexural strength, would enable the increased use of this product in new applications in construction. The aim of this study is to produce high-performance soil-cement (HPSC) specimens and to evaluate and compare this new material with high-performance concrete (HPC) in terms of flexural strength. A total of 12 specimens were produced with a mixture of 23.5% (by mass) of cement with the application of 10 MPa of pressure for its compaction. The results show that, at 28 days, the specimens reached an average strength of 6.73 MPa and, at 240 days, 12.34 MPa. This means that the HPSC reached a flexural strength resistance equivalent to HPC without the need for mined materials, such as sand and gravel, or the additives adopted in some doses of HPC, such as superplasticisers. Therefore, when using local soil, HPSC can be considered an environmentally preferable alternative to HPC for many construction applications where flexural strength is a requirement.Peer ReviewedPostprint (published version