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This paper reports results of laboratory and 3D numerical modeled pull-out tests with steel ladders and polymeric strip reinforcements. These types of reinforcement are commonly used in reinforced soil walls constructed with concrete facing elements. Laboratory pull-out tests are required to determine accurate and realistic pull-out strength values considering the interaction of specific reinforcement and backfill materials under different confining pressures (i.e., trying to simulate the different reinforcement layer arrangements and load conditions in actual reinforced soil walls). International design Codes for reinforced soil walls provide default values for pull-out strength. However, in many cases, default values are too conservative and/or are not strictly specified for particular reinforcement types. Pull-out tests can be difficult and expensive to perform, thus not being common nor worth for the vast majority of reinforced soil wall projects. Consequently, calibrated numerical models can be useful to predict pull-out response under site-specific conditions, and provide further understanding of the mechanisms involved in the soil-reinforcement interaction. Details of the numerical approach, including relevant aspects of the soil-reinforcement interfaces, are described. Examples of calibrated numerical predictions for pull-out loads, displacements, and soil-dilatancy effects are presented. The influence of reinforcement, soil and interface stiffnesses is shown. Numerical results provide useful insight for future modelling works of the complex interaction between type-specific backfill materials and reinforcement element, relevant for investigation and/or practical design of reinforced soil walls., Peer Reviewed, Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura, Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant, Postprint (published version)

In recent years, rooftops have been used as productive spaces for local resource (e.g. food, water, or energy) production. The main objective of this study is to demonstrate the potential of hyperspectral data to identify roof materials in cities. The case study area is located in a Mediterranean region north of Barcelona (Spain); diverse building typologies, building uses (residential, industrial, office, services and retail) and population densities constitute this study area. Two hyperspectral remote sensors (HRSs) were used to obtain hyperspectral images. Seven roof classes were identified using the k-means clustering algorithm. Most roofs were identified as metals (33 percent), followed by ceramic tiles (22 percent). The findings showed that 51 percent of roofs could be suitable for food, water, or energy production. Nevertheless, for a more reliable assessment of this potential, more criteria are needed., This work is part of the Fertilecity II project supported by the Spanish Ministry of Economy and Competitiveness (CTM2016-75772-C3-3-R and CTM2016-75772-C3-1-R, AEI/FEDER, UE); from the Spanish Ministry of Science, Innovation and Universities; through the María de Maeztu program for Units of Excellence (CEX2019-000940-M) and supported by MOVE4EDU. Authors want to thank to the University of Guadalajara (Mexico) for awarding a research scholarship to Perla Zambrano-Prado, and to the reviewers for their valuable comments., Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles, Objectius de Desenvolupament Sostenible::13 - Acció per al Clima, Postprint (author's final draft)

La industria cementera ha manifestado su firme compromiso con la reducción de las emisiones de dióxido de carbono mediante su hoja de ruta para alcanzar la neutralidad climática en 2050 a lo largo del ciclo de vida de sus productos, compuesta por cinco etapas (‘5Cs’: clínker, cemento, concreto/hormigón, construcción y carbonatación) en cada una de las cuales se incluyen distintas actuaciones. La reducción del factor clínker es una de las más relevantes en el contexto de la segunda etapa ‘cemento’. Debido a la necesidad de incrementar la cantidad de adiciones disponibles para la fabricación de cemento pórtland, es necesario evaluar la viabilidad de todo tipo de nuevas adiciones que puedan cumplir la función de reducir la relación clínker/cemento. Para ello, las empresas cementeras deben realizar estudios prenomativos de las que consideren potencialmente apropiadas y solicitar la normalización de los cementos pórtland que las contengan en el contexto de UNE, en España, antes de iniciar el proceso de normalización europeo (CEN). El paso siguiente sería su reglamentación para uso estructural mediante su incorporación a la Instrucción para la Recepción de Cementos (RC vigente) y al Código Estructural. En este artículo se analizan las adiciones que en estos momentos se consideran potencialmente más favorables para su inclusión en cementos, así como las propiedades básicas que son ya conocidas., Peer Reviewed, Postprint (author's final draft)

It is widely accepted that urban agriculture provides multiple benefits to society. Rooftop greenhouses are a form of urban agriculture that take advantage of urban resources (urban land, building materials, sunlight spaces) and waste flows (energy, nutrients) to provide food and ecosystem services to cities. However, the integration of urban greenhouses within buildings is a complex issue that must be addressed in-depth. Compared to the well-known conventional greenhouses, the urban environment display different constrains requiring to be assessed in order to later optimize greenhouse building materials. The aim of our study was to environmentally assess rooftop greenhouses and propose improving scenarios. Life cycle assessment was used to detect environmental hotspots and to evaluate different impact categories of an iRTG case study in the Barcelona area. Results showed that the greenhouse environment and ventilation design directly determine greenhouse structures and environmental impacts. Optimized strategies showed a potential reduction of up to 35% of the amount of structural steel used, while less improvement potential existed for covering materials (5%). Compared to conventional greenhouses, 1.6 times more steel and up to 8 times more energy were required to build the urban greenhouse in this study. The assessment revealed that these differences can be reduced by optimizing greenhouse structures to avoid a shift of material flows and environmental impacts from building urban greenhouses compared to conventional greenhouses. In turn, the assessment presented here provides guidelines on how to design and plan urban greenhouse constructions in future assessments. That will facilitate the incorporation of urban agriculture in cities based on consistent environmental assessments, ultimately contributing to the low-carbon future development of cities., The authors are grateful to the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement of Generalitat de Catalunya for awarding a research scholarship (FI-DGR 2021) to Joan Muñoz-Liesa. The authors also acknowledge financial support from the Secretaria d’Universitats i Recerca del Departament de Recerca i Universitats of the Generalitat de Catalunya for the grant awarded under AGAU 2020 PANDE 00021 and the Spanish Ministry of Science, Innovation and Universities through the “Marı́a de Maeztu” program for Units of Excellence in R&D [CEX2019–000940-M]., Peer Reviewed, Objectius de Desenvolupament Sostenible::9 - Indústria, Innovació i Infraestructura, Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles, Objectius de Desenvolupament Sostenible::12 - Producció i Consum Responsables, Postprint (author's final draft)

Solar radiation transmissivity in greenhouses is a key property largely determined by covering materials. This study compared tomato crop yields and their environmental performance of a polycarbonate rooftop greenhouse with alternative covering materials displaying higher solar transmissivity and lifetime performance. An integrated approach using experimental data with structural, energy modeling was used to model average lifetime crop productivities. At building functional unit (per m2·year), impacts varied between -29.0% and +24.0% compared to the current polycarbonate. Lifetime transmissivities improved up to 20.5% (4 mm-antireflective glass), leading to +46.6% of tomato yields (19.9 ± 2.2 kg/m2), and up to -33.9% of environmental impacts. Ethylene tetrafluoroethylene 60 µm-film resulted in 19.2 ± 2.3 kg tomatoes/m2 but improved environmental performance up to 41.7%. These results demonstrate the importance of employing integrated and life-cycle approaches to combine multiple trade-offs and dynamics within environmental assessments of greenhouse crops. The results are intended to contribute to improving greenhouse cultivation and sustainability., Peer Reviewed, Postprint (published version)

Los muros de contención son estructuras geotécnicas con una amplia gama de soluciones para realizar la misma función. Cada vez más, se les pide a los ingenieros geotécnicos que encuentren la mejor solución entre varias opciones en diferentes aplicaciones de ingeniería basadas en el impacto ambiental, el costo y los problemas sociales / funcionales. La evaluación de estos tres pilares durante el proceso de selección de una estructura se denomina evaluación de sostenibilidad. Este documento describe una metodología de evaluación de la sostenibilidad y ofrece ejemplos para seleccionar la mejor opción sostenible para muros de 5 m de altura, eligiendo entre muros en voladizo y gravedad convencionales, y muros de suelo reforzado con refuerzo polimérico y metálico. Los análisis se llevaron a cabo utilizando la metodología MIVES que se basa en la teoría del valor y supuestos multiatributo. El documento identifica cómo se puntúan, ponderan y agregan los diversos indicadores para generar puntuaciones numéricas finales que permitan clasificar las opciones de solución. Los puntajes finales incluyen un ajuste basado en las preferencias de las partes interesadas por la importancia relativa de los tres pilares de sostenibilidad (ambiental, económico (costo) y social / funcional). Para una altura de 5 m, los resultados del análisis muestran que las soluciones de muros de suelo reforzado suelen ser la mejor opción en comparación con las soluciones de muros voladizos y por gravedad convencionales y, por lo tanto, la elección final cuando las puntuaciones de cada pilar se agregaron en una puntuación única. También se incluye un análisis de sensibilidad de la elección de funciones de valor y las preferencias de ponderación de las partes interesadas en los puntajes de clasificación final utilizados para seleccionar la mejor solución sostenible. Los análisis también muestran que la elección de la función de valor y las preferencias de las partes interesadas pueden llevar a que una estruc, Postprint (published version)

Soil-facing mechanical interactions play an important role in the behaviour of earth retaining walls. Generally, numerical analysis of earth retaining structures requires the use of interface elements between dissimilar component materials to model soil-structure interactions and to capture the transfer of normal and shear stresses through these discontinuities. In finite element method software programs, soil-structure interactions can be modelled using “zero-thickness” interface elements between the soil and structural components. These elements use a strength/stiffness reduction factor that is applied to the soil adjacent to the interface. However, in some numerical codes where the zero-thickness elements (or other similar special interface elements) are not available, the use of continuum elements to model soil-structure interactions is the only option. The continuum element approach allows more control of the interface features (i.e., material strength and stiffness properties) as well as the element sizes and shapes at the interfaces. This paper proposes parameter values for zero-thickness elements that will give the same numerical outcomes as those using continuum elements in finite element and finite difference commercial software. The numerical results show good agreement for the computed loads transferred from soil to structure using both methods (i.e., zero-thickness elements and continuum elements at interfaces). Both different interface modelling approaches can give very similar results using equivalent interface property values, and demonstrates the influence of choice of numerical mesh size on the numerical outcomes when continuum elements are used at the interfaces., Peer Reviewed, Postprint (published version)

This study examines urbanization patterns linked to social housing units and the way in which such patterns influence the practice of urban agriculture (UA) in Mexico. Due to the transformations that take place over time in Mexican social-housing units, impervious surfaces tend to increase at the expense of greenspace and UA possibilities. The research aims to identify the negative impact of social housing transformations on UA and suggest a policy framework for sustainable housing development in Mexico. The empirical analysis distinguishes four social housing typologies within two emblematic neighborhoods in the city of Merida, Mexico: Las Magnolias and Ampliación Tixcacal-Opichén. A survey of 157 housing units combines quantitative metrics and qualitative descriptors to unveil the detrimental impact of development on UA. The results show that UA takes place within the building lots and around the housing units, rather than in public urban areas. 60% of the sampled units practiced UA, with traditional backyard gardens being the most common modality. The research findings point to a systematic expansion of impervious surfaces, limitation of both cultivation choices and crop variety, and major restrictions on UA practices. Social housing represents the bulk of residential developments in Mexico (42.7% out of 35.5 million housing units). Left unregulated, the types of social housing transformations that have been empirically verified in this study endanger the availability of green space as the primary resource for UA. This research sheds light on critical policy changes and formulations that are required to enhance UA practices and to establish greener cities and more sustainable housing development., Peer Reviewed, Postprint (published version)

Buildings and greenhouses consume vast amounts of energy and natural resources for heating and ventilation. It is still unclear how the synergetic effect of combining greenhouses and buildings' forced waste airflows could improve both systems' energy efficiency. This study quantified the energy recovery potential of exchanging airflows in a rooftop greenhouse (iRTG) integrated with an office building HVAC system in a Mediterranean climate. Using monitored and calibrated energy model data, the results showed that the iRTG can act as a solar collector and as a sink for a building's low-grade waste heat. The magnitude of harvested thermal energy that could be recirculated into the building by the integrated HVAC system was 205.2 kWh/m2y-1 and was limited by greenhouse low transmissivity (54%). The magnitude of building exhaust air was 198 kWh/m2y-1 at temperatures sufficient to heat and cool the iRTG. Compared to a passive ventilated configuration, the integration of active ventilation strategies doubled the energy benefits. Building ventilation requirements directly determined building and greenhouse waste flows and energy benefits, which increased by 63.1% when air changes per hour moved from 1.59 to 3.16. Overall, this demonstrates that greenhouse and building functionalities could be coupled to contribute to urban circularity and sustainability., The authors are grateful to the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya (Catalonia) for the award of a research scholarship (FI-DGR 2020) to Joan Muñoz-Liesa. Authors also acknowledge financial support from the Secretaria d'Universitats i Recerca del Departament de Recerca i Universitats de la Generalitat de Catalunya for the grant awarded under AGAU 2020 PANDE 00021 and the Spanish Ministry of Science, Innovation and Universities, through the “María de Maeztu” program for Units of Excellence in R&D [CEX2019-000940-M]. This work was additionally enabled by the Càtedra JG Ingenieros – Universitat Politècnica de Catalunya and the UK Engineering and Physical Sciences Research Council grant EP/P001173/1. Authors are also grateful to Elisa López-Capel, Sostenipra research group and ICTA-UAB staff for the very valuable support, advice and help., Peer Reviewed, Objectius de Desenvolupament Sostenible::11 - Ciutats i Comunitats Sostenibles, Objectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant, Postprint (published version)

The main objective of this study is to contribute a framework and to provide an overview of potential key factors, policies, and barriers associated with the integration of rooftop urban agriculture (RUA), building on stakeholders' perspectives in four European cities (Barcelona, Berlin, Bologna, and Paris). The research was developed in two phases, namely, a workshop and a survey of stakeholders involved in RUA from the four cities. Education, environmental, research, technological innovation, food production, and social factors play an important role in implementing RUA. Productive spaces, cultural values, social cohesion, social rural-urban links, and the high cost of urban land are highlighted as factors that “promote” RUA. In contrast, the cost of water and pollution are major contextual factors that constrain RUA. Policies related to food trade and urban planning are those that most limit RUA development. Major architectural and technical barriers related to the limits on building heights, historical buildings, a lack of specific building codes, building design and roof accessibility were identified. The high cost of infrastructure and policies that prohibit RUA product sales emerged as economic constraints. Major differences among the cities studied included the perceived effect of urban policies on RUA diffusion as well as the perceived relevance of economic and pollution factors. This study revealed that extensive dissemination and the development of appropriate information about RUA are needed. The creation of new regulations, as well as modifications to urban and building codes to support RUA, is also envisaged. This approach will consider a more flexible land-use policy that allows agriculture to take place in cities as well as marketing frameworks for RUA products. For future studies, it would be useful to apply the framework developed in this study to a larger sample. A study is also needed to confirm hypothetical differences between cities., Peer Reviewed, Postprint (published version)

This work established a framework to identify and analyze the technical feasibility of roofs for integrating urban agriculture, rainwater harvesting, and photovoltaic systems using various remote sensing. The framework was applied to a region north of Barcelona. Three levels of solar access requirements for tomatoes, leafy crops, strawberries, and microgreens were established. The case study included compact and disperse urban forms, residential and nonresidential building uses and various building typologies. It was identified that 8% of the roof area is feasible for tomato and lettuce production, and production could satisfy the 210% of average intake of tomatoes and the 21% average yearly consumption of lettuce. Rainwater harvesting systems could supply 94.26% of the water requirements for lettuce growing in an open-air system; in contrast, 53% of irrigation could be satisfied for tomato production in rooftop greenhouse systems. The results showed a potential for 80% of roof area to be used for rainwater harvesting systems, representing the average yearly water consumption of 44% of citizens for laundry, showering, toilet flushing, cleaning and irrigation uses. Finally, 50% of the roofs are suitable for photovoltaic panels, representing an average energy consumption of 18% of citizens., This work is part of the Fertilecity II project supported by the Spanish Ministry of Economy and Competitiveness (CTM2016-75772-C3-3-R and CTM2016-75772-C3-1-R, AEI/FEDER, UE); from the Spanish Ministry of Science, Innovation and Universities. This research has received financial support from the European Union's Horizon 2020 research and innovation program under grant agreement No 862663. The publication reflects the author's views. The Research Executive Agency (REA) is not liable for any use that may be made of the information contained therein. This work was supported by the “María de Maeztu” program for Units of Excellence in R&D (CEX2019-000940-M). Authors want to thank to Assumpció Termes and Fernando Pérez-Aragüés from the Institut Cartogràfic i Geològic de Catalunya for their valuable support, to the Greenhouses to reduce CO2 on Roofs (GROOF) project, to the reviewers and editor for their observations, also to the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya for the award of a research scholarship (FI-DGR 2018) to Joan Muñoz-Liesa and to the University of Guadalajara (Mexico) for awarding a research scholarship to Perla Zambrano-Prado., Peer Reviewed, Postprint (published version)

Urban and building systems are awash with materials. The incorporation of green infrastructure such as integrated rooftop greenhouses (iRTGs) has the potential to contribute to buildings’ and cities’ circularity. However, its greater sophistication than conventional agriculture (CA) could lead to a shift in environmental impacts. One of the key elements for greenhouse building-integrated agriculture (BIA) and CA to achieve high levels of environmental performance is their structural design, which largely impacts the economic and environmental life-cycle costs (by up to 63%). In this context, the study assessed iRTGs life-cycle material and energy flows and their environmental burdens at structural level (m-2y-1) within life cycle assessment (LCA), based on a case study in Barcelona. A structural assessment following European standards allowed the identification of key design factors to minimize the environmental impacts of RTGs’ structure within improvement scenarios. The assessment revealed that a steel structure in a business-as-usual (BAU) scenario contributed from 31.5 to 67.3% of the impact categories analyzed, followed by the polycarbonate covering material (from 21.8 to 45.9%). The key design factors responsible for these environmental impacts were ground height, ventilation design, building integration and urban location. The improvement scenarios compensated for additional steel inputs by up to 35.9% and decreased environmental impacts that might occur in the BIA context by 24.1% compared with the BAU scenario. The assessment also revealed that urban environments do not imply shifting environmental impacts per se, as greenhouse BIA structures can benefit from their advantageous characteristics or be compensated by optimized greenhouse structures., The authors are grateful to the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya for the award of a research scholarship (FI-DGR 2018) to Joan Muñoz-Liesa; to the Spanish Ministry of Education, Culture and Sports grant FPU16/03238 to Susana Toboso-Chavero; and to the European Union's Horizon2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 842460 to Angelica Mendoza Beltran. Authors also acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) for the financial support to the research project Fertilectiy II “Integrated rooftop greenhouses: energy, waste and CO2 symbiosis with the building. Towards foods security in a circular economy” (CTM2016–75772-C3–1-R; CTM2016–75772-C3–2-R) and the Spanish Ministry of Science, Innovation and Universities, through the “María de Maeztu” program for Units of Excellence (MDM-2015–0552). Authors would also gratitude Dr. Violeta Vargas, Dr. Xavier Gabarrell, Dr. Joan Rieradevall, Dr. Martí Rufí-Salís, Dr. Gara Villalba and the ICTA-UAB staff for the very valuable support advise and help., Peer Reviewed, Postprint (author's final draft)

The main objective of this study is to analyze the perceived barriers and opportunities with regard to the implementation of urban agri-green roofs (UAGR) in cities. The case study was conducted in Barcelona, a Mediterranean compact city. The World Café method was used in this work. Five categories of barriers and opportunities were discussed (social, environmental, legal/administrative, technological/architectural, and economic) by interdisciplinary stakeholders. A total of 129 barriers and opportunities were identified. The main barriers identified were as follows: the lack of information and social cohesion regarding UAGR projects; the Mediterranean climate; the lack of specific regulations and protocols; the initial investment; and the pre-condition of the roof and its load bearing capacity. The main opportunities were social cohesion; improved life quality; new specific regulations; the profits derived from UAGR projects; and aesthetic improvement. The UAGR's scale of impact results showed a homogeneous distribution between “building” and “city”, while the “global” scale remains residual. Regarding the stage of the UAGR life cycle at which barriers and opportunities emerge, the results highlight how most opportunities appear during the “use” stage of the roof, whereas barriers do so during the “project” stage., Peer Reviewed, Postprint (published version)

The final publication is available at Springer via http://dx.doi.org/10.1007/s11440-020-01057-w, This paper reports the results of 3D numerical modelling of a 6-m-high mechanically stabilised earth (MSE) wall constructed with concrete panels and steel or polymeric strip reinforcement. These systems pose numerical challenges as a result of the discontinuous reinforcement arrangement which is not the case for MSE walls constructed with continuous reinforcement layer configurations. Details of the numerical approach including modelling of the reinforcement strips, concrete facing panels and compressible bearing pads between panels are described. Examples of numerical predictions for facing deformations, toe loads due to soil down-drag behind the panels, soil and reinforcement settlements, and reinforcement tensile loads are presented. The influence of reinforcement stiffness is demonstrated by comparing numerical predictions for the same MSE wall with relatively inextensible steel strips and with relatively extensible polymeric strips. Of particular interest are the results showing the disruption of earth pressures along vertical and horizontal planes in the reinforced soil zone as a result of the discontinuous strip inclusions, and the vertical load that accumulates on the reinforcement strips close to the connections due to soil settlement behind the facing. The details of the modelling approach used here and the lessons learned provide a benchmark for future similar lines of investigation and for practitioners, particularly as the computational power of desktop computers continues to increase., The authors wish to acknowledge the support of the International Center for Numerical Methods in Engineering (CIMNE) and the funding received from the Spanish Ministry of Economy and Competitiveness through the ‘‘Severo Ochoa Programme for Centres of Excellence in R&D’’ (CEX2018-000797-S), and the Natural Sciences and Engineering Research Council of Canada (NSERC) (Grant Number: 94344-2013)., Peer Reviewed, Postprint (author's final draft)

Roof characteristics such as material type and their properties information are essential to integrating urban agriculture (UA), rainwater harvesting systems (RWHS), and energy systems on roofs. Roof materials can be identified from their spectral signatures. However, this identification requires a priori knowledge of the materials’ spectral characteristics. The main perspective of this work is the future use of spectral data for roof classification. A common practice in mapping materials is the use of spectral libraries. In this regard, this work describes a novel framework for laboratory-based spectral data acquisition. The reflectance data of common, recently introduced (plastics and metals), and representative roof materials from the Mediterranean region were obtained. Data acquisition was conducted in a laboratory under controlled conditions using a high-spatial-resolution (HSR) sensor, which is usually used for airborne surveys. Large variations in the spectral reflectance data were observed due to the composition of the roof material. Flat spectral signatures were found for fibre cement, concrete, gravels and some metals, especially from the near-infrared (NIR) spectral region. Colour and surface finish greatly influence the visible (VIS) spectral range. It was confirmed that the view angle did not modify the spectral shapes. A collection of 39 spectral data of roof materials (ceramics, concrete, fibre cement, metals, plastics, paints, stone, and wood) were compiled into a spectral library that is available online., This work is part of the Fertilecity II project supported by the Spanish Ministry of Economy and Competitiveness (CTM2016-75772-C3-3-R and CTM2016-75772-C3-1-R, AEI/FEDER, UE); from the Spanish Ministry of Science, Innovation and Universities; through the María de Maeztu program for Units of Excellence (MDM-2015-0552). Authors want to thank to the University of Guadalajara (Mexico) for awarding a research scholarship to Perla Zambrano-Prado, and to the reviewers for their valuable comments., Peer Reviewed, Postprint (author's final draft)

A major concern for sustainable development is urban systems energy consumption. A possible way to gain additional whole system energy efficiencies is to integrate rooftop greenhouses (iRTG) on unoccupied roofs. This work presents actual environmental data (2015–2018) and calibrated energy modelling results to analyze the energy symbiosis between an iRTG and the host building. Simulation results illustrate that annually 98 kWh/m2 of heating energy is passively recovered (84% during night time) from the building by the iRTG. Conversely the iRTG insulating capacity resulted in annual energy saving of 35 kWh/m2 for the host building (equal to 4% of the building’s annual energy needs). When combined an overall 128 kWh/m2 of net energy savings and 45.6 kg CO2 eq/m2 of savings are realised via iRTG. On average, iRTG daytime temperatures can be 5.1 °C warmer (summer) and -4.3 °C cooler (winter) than the building. This presents major potentials for recovery and exchange of heating and cooling energy flows through integrating heating and ventilation air conditioning systems of the building and iRTG. Hence, iRTGs can provide a source of renewable energy as well as a sink for building exhaust air to improve energy efficiencies of urban built environment and urban agriculture., The authors are grateful to the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya for the award of a research scholarship (FI-DGR 2018) to Joan Muñoz-Liesa; to the Universitat Autònoma de Barcelona for the award of a research scholarship (PIF-2017) to Martí Rufí-Salís; to the Spanish Ministry of Economy and Competitiveness (MINECO) for the financial support to the research project Fertilectiy II “Integrated rooftop greenhouses: energy, waste and CO2 symbiosis with the building. Towards foods security in a circular economy” (CTM2016-75772-C3-1-R; CTM2016-75772-C3-2-R). Authors also acknowledge financial support from the Spanish Ministry of Science, Innovation and Universities, through the “María de Maeztu” program for Units of Excellence (MDM-2015-0552). This work was additionally enabled by the Càtedra JG Ingenieros – Universitat Politècnica de Catalunya and the UK Engineering and Physical Sciences Research Council grand EP/P001173/1. Authors also thank Oriol Baeza, Prof. Xavier Gabarrell, Prof. Joan Rieradevall and the ICTA-UAB staff for their very valuable supporting advise and help., Peer Reviewed, Postprint (author's final draft)

Background:Global food production systems generate impacts such as eutrophication, caused by nutrient run-offfrom agricultural exploitations and exacerbated by climate change. Hydroponic cultivation methods arecommon in Mediterranean areas, although there is a gap in the literature with regard to their study. This studyaims tofill that gap, by assessing nutrientflows in hydroponic crops.Results:The results showed that most of the nutrients were drained with the leachates (51% on average), afigurewhich could be lower, if the nutrient supply were adjusted to the needs of the plants or if (closed hydroponic)nutrient recirculation were implemented, without compromising the nutrient uptake of the plant. Moreover, thestudy revealed that a significant quantity of nutrients was retained in the substrate (perlite) during the crop,reaching average values of 5% of incoming calcium, 6% of nitrogen, and 7% of phosphorus. In the case ofphosphorus and calcium, a regression model is presented for the estimation of their retention in hydroponiccrops.Conclusions:Although further studies will be needed to confirm the above trends, the study makes a significantcontribution to understanding the metabolism of nutrients in hydroponic crops and tofiner adjustments of thenutrient balance., Peer Reviewed, Postprint (published version)

There is great potential to reduce the environmental impact of the building sector, which is now an area of immense importance, through the optimisation of construction materials and components. This study assesses both the design and the construction of Concrete Deep Foundations (CDFs), which are widely used in construction, from an environmental perspective considering the following variables: (i) grade of prefabrication, i.e., fully cast in situ, partly prefabricated, and fully prefabricated; (ii) compressive strength of cast-in-situ concrete; and (iii) building design codes, i.e., current Spanish codes (EHE-08 and CTE), Eurocode with the Spanish annexes, and Eurocode with the United Kingdom annexes. In addition, the results of Dynamic Load Tests (DLTs) and the economic cost of several CDFs are evaluated. Geotechnical and structural designs of CDFs are carried out along with their life-cycle assessment. Some of the main findings include: (i) partially and fully prefabricated CDFs and conducting DLTs reduced the environmental impact in most categories (by up to 44% for global warming emissions) compared to the fully cast-in-situ CDFs, although they were 12–37% more expensive; (ii) changing the compressive strength of the concrete (in piles and cap) in fully cast-in-situ CDFs from 25 to 35¿MPa reduced the environmental impact by up to 14–17% in all categories and economic costs by up to 12%; and, (iii) CDFs with bored piles resulted in the lowest environmental burden when designed with Eurocode and UK annexes (11–31% less impact), as did CDFs with driven piles designed with current Spanish codes (11–18% less impact). The study variables and sensitivity analysis showed a significant effect on the results and should be considered in future construction, research, and building codes., Peer Reviewed, Postprint (author's final draft)

L'urbanisme sostenible promou el desenvolupament d'estratègies amb l'objectiu de la sostenibilitat del territori. Una d'aquestes estratègies és l'agricultura urbana (AU). Específicament, els hivernacles en cobertes o terrats (RTGs) permeten el cultiu d'aliments a la ciutat sense comprometre superfície de sòl permeable. No obstant això, la investigació que abordi el seu comportament energètic i que brindi eines per a la quantificació i anàlisi de la seva viabilitat és limitada. A Amèrica Llatina i al Carib (ALC), l'estudi de la AU encara es troba en una etapa inicial, fet pel qual és necessari aprofundir i promoure el seu estudi. La present tesi doctoral pretén cobrir aquests àmbits d'estudi a través d'intentar donar resposta a les següents quatre preguntes: -Per als països desenvolupats (i) En quina mesura les eines urbanes, arquitectòniques, socials i sostenibles contribueixen a avaluar el potencial d'implementació de l'agricultura en terrats d'edificis existents en ciutats del sud d'Europa?, (ii) Pot la integració d'un hivernacle al terrat d'un edifici, aprofitant el seu intercanvi de fluxos tèrmics residuals, contribuir tecnològicament i arquitectònicament al desenvolupament de l'agricultura urbana?; -per als països en vies de desenvolupament (iii) Quin és el panorama actual de l'agricultura urbana als països en desenvolupament d'Amèrica Llatina i el Carib?, (iv) Quines són les implicacions de la planificació urbana i l'habitatge social en la promoció de l'agricultura urbana per a la sostenibilitat de la ciutat llatinoamericana de grandària mitjana? La tesi inclou un marc interdisciplinari. En cada línia de recerca estudiada s'han utilitzat materials i mètodes complementaris per a l'obtenció de dades específiques: sensors aerotransportats, sensors de temperatura i humitat de l'aire, diversos programaris, revisió documental, entrevistes i grups d'interès, entre d'altres. Els resultats van demostrar que un hivernacle integrat al terrat (iRTG) pot proporcionar tempe, El urbanismo sostenible promueve el desarrollo de estrategias en pro de una sostenibilidad del territorio. Una de estas estrategias es la agricultura urbana (AU). Específicamente, los invernaderos en la azotea (RTGs) permiten el cultivo de alimentos en la ciudad sin comprometer superficie de suelo permeable. Sin embargo, las investigaciones que aborden su comportamiento energético y que brinden herramientas para la cuantificación y análisis de su viabilidad son limitadas. En América Latina y el Caribe (ALC), el estudio de la AU aún se encuentra en una etapa inicial, por lo que es necesario profundizar y promover su estudio. La presente tesis doctoral pretende cubrir estos ámbitos de estudio a través de intentar dar respuesta a las siguientes cuatro preguntas: -Para los países desarrollados (i) ¿En qué medida las herramientas urbanas, arquitectónicas, sociales y sostenibles contribuyen a evaluar el potencial de implementación de la agricultura en azoteas de edificios existentes en ciudades del sur de Europa?, (ii) ¿Puede la integración de un invernadero en la azotea de un edificio, aprovechando su intercambio de flujos térmicos residuales, contribuir tecnológicamente y arquitectónicamente al desarrollo de la agricultura urbana?; -para los países en vías de desarrollo (iii) ¿Cuál es el panorama actual de la agricultura urbana en los países en desarrollo de América Latina y el Caribe?, (iv) ¿Cuáles son las implicaciones de la planificación urbana y la vivienda social en la promoción de la agricultura urbana para la sostenibilidad de la ciudad latinoamericana de tamaño mediano? La tesis incluye un marco interdisciplinar de diversas disciplinas. Y en cada línea de investigación estudiada se han utilizado materiales y métodos complementarios para la obtención de datos específicos: sensores aerotransportados, sensores de temperatura y humedad del aire, diversos softwares, revisión documental, entrevistas, grupos de interés, y otras. Los resultados demostraron que un invern, Sustainable urbanism promotes strategies for the sustainability of the territory. One of these strategies is urban agriculture (UA). Specifically, rooftop greenhouses (RTGs) are an alternative that in recent years has had a considerable rise in European compact cities, as they enable the cultivation of food in the city without compromising permeable soil surface. However, research that addresses their energy behavior and provides tools for the quantification and analysis of their viability is limited. In the case of Latin America and the Caribbean, the study of UA is still in an initial stage, so it is necessary to deepen and promote its analysis. In this sense, the present doctoral thesis aims to cover these areas of study and answer the following four questions: -For developed countries (i) To what extent do urban-architectural, social and sustainable tools contribute to assess the potential for implementation of agriculture on roofs of existing buildings in Southern European cities?, (ii) Can the integration of a greenhouse into the rooftop of a building, taking advantage of its exchange of residual thermal flows, contribute technologically and architecturally to the development of urban agriculture? For developing countries (iii) What is the current state of urban agriculture in developing countries in Latin America and the Caribbean? and (iv) What are the implications of urban planning and social housing in the promotion of urban agriculture for the sustainability of the medium-sized Latin American cities? This thesis includes an interdisciplinary framework that combines aspects of various disciplines. In each line of research studied, complementary materials and methods have been used to obtain specific data: TASI-600 and Leica ALS50-II airborne sensors, air humidity and temperature sensors, various software, document review, interviews and focus groups, among others. The results showed that an integrated rooftop greenhouse (iRTG) can provide temperatures with

Today, food security has a critical place in the government agendas of developing countries. In Latin American case, urban contexts have been subject to radical transformations in the last decades, most apparently through the expansion of social housing, which may limit or condition access to food for the neediest population. Nowadays, in Latin America, there are numerous cases of urban agriculture. Quito (Ecuador) stands out for the development of urban agriculture through the Participatory Urban Agriculture Project - AGRUPAR; initiative that has led to the implementation of orchards with organic production, raising of small animals, food processing and marketing of surpluses for food-nutrition security. Above all, it has transcended its urban and peri-urban intervention to rural areas, favoring the urban-rural connection. Also, worldwide the urban agriculture is developed in different forms, one of which is through crops protected by a greenhouse on the roofs: Rooftop greenhouse (RTG). This form of UA uses specific substrates for hydroponic crops and has modern irrigation systems often combined with rainwater harvesting and provides a unique opportunity to improve urban agriculture in Quito. The purpose of this study is to identify the implementation potential of rooftop greenhouses in social neighborhoods in Quito. Standard methods to assess the potential use of rooftop greenhouses were adapted to a social neighborhood. The guidelines follow three steps: Step 1: Characterization based on criteria; Step 2: Available surface determination and Step 3: Production, self-sufficiency and self-supply. “La Comuna Santa Clara de San Millán” was selected as study area. The results showed that 33.2% (7.70¿ha) of the neighborhood rooftops had a short-term feasibility to install rooftop greenhouses, with the potential to produce 1,579,140 and 56,720¿kg/year of tomato and lettuce respectively. The research has developed reliable guidelines that prove the feasibility to install, Peer Reviewed, Postprint (published version)

Earth retaining walls are common geotechnical structures with a wide range of solutions available to perform the same function. More and more, geotechnical engineers are asked to find the best solution among several options in different civil engineering applications based on environmental impact, cost and societal/functional issues. Evaluation of these three pillars during the selection process of a structure (such as an earth retaining wall) is called a sustainability assessment. This paper describes a sustainability assessment methodology and gives examples to select the best sustainable option from candidate conventional gravity and cantilever wall types, and steel and polymeric soil reinforced mechanically stabilized earth (MSE) walls of 5 m height. Analyses were carried out using the MIVES methodology which is based on value theory and multi-attribute assumptions. The paper identifies how indicator issues are scored, weighted and aggregated to generate final numerical scores that allow solution options to be ranked. The final scores include an adjustment based on stakeholder preferences for the relative importance of the three sustainability pillars (environmental, economic (cost) and societal/functional). The analysis results show that MSE wall solutions are most often the best option in each category compared to conventional gravity and cantilever wall solutions and thus most often the final choice when scores from each pillar were aggregated to a final score. The paper also includes a sensitivity analysis of the choice of value functions and stakeholder weighting preferences on the final ranking scores used to select the best sustainable solution. The analyses also show that the choice of value function and stakeholder preferences can lead to a conventional structure being the best option., Postprint (author's final draft)

Urban agriculture has emerged as an alternative to conventional rural agriculture seeking to foster a sustainable circular economy in cities. When considering the feasibility of urban agriculture and planning for the future of food production and energy, it is important to understand the relationships between energy flows throughout the system, identify their strengths and weaknesses, and make suggestions to optimize the system. To address this need, we analyzed the energy flows for growing tomatoes at a rooftop greenhouse (RTG). We used life cycle assessment (LCA) to identify the flows within the supply chain. We further analyzed these flows using ecological network analysis (ENA), which allowed a comparison of the industrial system to natural systems. Going beyond LCA, ENA also allowed us to focus more on the relationships between components. Similar to existing ENA studies on urban metabolism, our results showed that the RTG does not mimic the perfect pyramidal structure found in natural ecosystems due to the system's dependency on fossil fuels throughout the supply chain and each industry's significant impact on wasted energy. However, it was discovered that the RTG has strong foundational relationships in its industries, demonstrating overall positive utility; this foundation can be improved by using more renewable energy and increasing the recycling rates throughout the supply chain, which will in turn improve the hierarchy of energy flows and overall energy consumption performance of the system., Peer Reviewed, Postprint (author's final draft)

Rapid global urbanisation in 21st century results in cities consuming vast resources but also offering unique opportunities for more integrated and circular resource management. This work investigates potential benefits of urban agriculture and buildings integration through a demonstrator building (ICTA). Actual building and integrated Rooftop Greenhouse (iRTG) data demonstrate wide thermal profiles across ICTA six levels and the potential for heat exchange within the building. Calibrated model monthly results indicate reduced building heating needs resulting from iRTG inclusion. However, more modest GSHP electrical cooling reductions resulting from plant transpiration showed reversing potential which requires more in-depth analysis of underlying principles., The authors are grateful to the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya for the award of a research scholarship (FI-DGR 2016) to Joan Muñoz Liesa; the Spanish Ministry of Economy and Competitiveness (MINECO) for the financial support of the research project Fertilectiy II “Integrated rooftop greenhouses: energy, waste and CO2 symbiosis with the building. Towards foods security in a circular economy” (CTM2016-75772-C3-1-R; CTM2016-75772-C3-2-R) and the María de Maeztu program for Units of Excellence in R&D (MDM-2015-0552)., Peer Reviewed, Postprint (published version)

El Pla Energia2020 de la UPC promou l'eficiència energètica i la gestió de les instal·lacions en els seus edificis. En aquesta línia, aquest treball pretén avaluar energèticament els dos edificis corresponents a l'ETSAB utilitzant els sistemes tecnològics més eficients per a cobrir les necessitats i proposant mesures de millores avaluades econòmicament. El propòsit és avançar cap als objectius que marquen les polítiques europees en matèria d'eficiència energètica als edificis. La UPC serà un laboratori per a assajar l'estratègia nZEB.

Assuming specific behavior models, the variety of design codes currently used for the design of concrete beams inevitably results in different solutions, ensuring service during the expected lifetime with a maximum functional quality and safety. However, from a sustainable design perspective, such differences may have remarkable environmental impacts. This paper analyses if the approach of the newest design code, i.e., the Model Code, leads to a reduction in resource consumption and greenhouse gas emissions (GHG) over the life cycle of concrete beams. To do so, a comparative analysis of the environmental impact of concrete beams was carried out depending on the reference code used for their design (i.e., EHE-08 or Model Code). The results show that reducing the amount of reinforcing steel is essential to minimize the life cycle environmental impacts of concrete beams. Every country may have its own design codes and, thus, the reinforcing steel use can vary for structures subjected to the same loads and with equivalent structural reliability. Hence, regulations play a key role in the sustainability of construction assets. Conclusions depend on the beam’s length (L), height (h) and characteristic compressive strength (fck). For short beams (4 m), the greater the h, the greater the reinforcement difference between the two codes. With regard to beams with L = 8 m, these differences can lead to varying steel and GHG savings, e.g., up to 5.0 % with MC-2010 (h = 0.6 m and fck = 35 MPa), almost 40 % with EHE – 08 (h = 0.6 m and 35 MPa < fck = 50 MPa) and more than 30 % with MC-2010 (h = 1.0 m).. For long beams (L = 12.0 m), steel consumption is 0.3 % to 19 % lower when the beam is designed with EHE-08, and this difference decreases as fck increases., Peer Reviewed, Postprint (author's final draft)

Food security is at the heart of governmental agendas of developing countries. In Latin America, urban agriculture (UA) offers an interesting alternative to ensuring a sufficient, safe and nutritious food supply for urban populations. However, Latin American cities have been subject to radical transformations in the last decades, most apparently through the expansion of social housing. The main objective of this research is to analyze the social perceptions and feasibility of UA in Mexican social housing neighborhoods. The Mérida city was used as a representative case study. Structured interviews were given to 65 key stakeholders across different categories (residents, urban government officials and technical experts). The results indicate a nonexistent perception of UA in Mérida, despite the secular agricultural tradition of the Yucatan region. Nevertheless, respondents agreed in their interest in potentially developing UA activities to improve diets, increase green areas, support local economies, and reduce CO2 emissions. The main perceived barriers for UA are the prevalent model of housing, with a very limited floor area, and the current approach to urban planning, which lacks non-built-up areas. Significantly, large artificialized zones create suitable areas to implement UA on extended rooftops. Finally, stakeholders demand the intervention of authorities at different levels (Federal [national], State [regional] and local) as a requirement to develop UA properly. The main pathways for this support should be to prepare new urban and housing policies and introduce economic incentives., Peer Reviewed, Postprint (author's final draft)

Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the production of these resources. We developed the Roof Mosaic approach, which combines life cycle assessment with two rooftop guidelines, to analyze the technical feasibility and environmental implications of producing food and energy, and harvesting rainwater on rooftops through different combinations at different scales. To illustrate, we apply the Roof Mosaic approach to a densely populated neighborhood in a Mediterranean city. The building-scale results show that integrating rainwater harvesting and food production would avoid relatively insignificant emissions (13.9–18.6 kg CO2 eq/inhabitant/year) in the use stage, but their construction would have low environmental impacts. In contrast, the application of energy systems (photovoltaic or solar thermal systems) combined with rainwater harvesting could potentially avoid higher CO2 eq emissions (177–196 kg CO2 eq/inhabitant/year) but generate higher environmental burdens in the construction phase. When applied at the neighborhood scale, the approach can be optimized to meet between 7% and 50% of FEW demands and avoid up to 157 tons CO2 eq/year. This approach is a useful guide to optimize the FEW nexus providing a range of options for the exploitation of rooftops at the local scale, which can aid cities in becoming self-sufficient, optimizing resources, and reducing CO2 eq emissions., Peer Reviewed, Postprint (published version)

The design of building foundations has usually been based on tradition, local practice, experience, and structural design codes. Safety is invariably considered the main factor and environmental criteria (or, in general, sustainability) is seldom given due consideration. However, similar safety indicators can be achieved with different variables and a minimum safety factor must always be ensured. The main objective of this study is, from an environmental perspective, to assess the influence of the construction system (cast-in-situ or precast), foundation type (rigid or flexible), and structural code (EC-2 or EHE-08) in the case of a concrete shallow foundation (CSF), using Life Cycle Assessment (LCA). Applying this methodology, the materials (concrete and steel) yielded the highest impacts in all categories, at around 95% for cast-in-situ CSFs and at around 85% for precast CSFs, both in relation to global warming. Consequently, optimization of the amount of these materials is crucial when considering the particular variables selected in this study. The results showed that cast-in-situ and flexible CSFs at moderately shallow depths (and therefore with less steel reinforcement) and precast CSFs with considerable reductions in concrete volumes (due to sloped shapes) had lower environmental impacts. In addition, cast-in-situ CSFs constructed in accordance with the EHE-08 structural code showed lower impacts, while precast CSFs complying with the EC-2 code were environmentally preferable. However, a specific study might be required for specific factors in each case (loads, soil type, structural settlement, among others). Relevant environmental effects associated with the three variables should therefore be given specific consideration in the development of structural design codes and future constructions., Postprint (author's final draft)

Food security in cities is an increasing concern due to the impact of climate change and the concentration of world population in cities. Urban agriculture (UA) aims at enhancing food production in urban areas, providing potential environmental advantages by reducing food transport, packaging and waste generation. Among UA alternatives, rooftop greenhouses (RTGs) are greenhouses built on top of urban roofs, in which mainly soil-less agriculture systems are used to produce food. When RTGs are integrated into the metabolism of their buildings, they exchange CO2, energy and water to improve their performance. This alternative is called integrated RTG (i-RTG). This chapter analyses the use of i-RTGs to improve buildings and cities’ metabolism and its particular application in the area of Barcelona. This analysis aims to define a new agricultural system from a technological and sustainability approach focusing on Mediterranean cities. Our research is based on the development and results of the Fertilecity project. A particular experimental analysis was conducted at ICTA’s i-RTG lab located near Barcelona. The main factors of interest are architectural and engineering requirements, urban integration, CO2 emissions management, energy consumption, food production, social integration and rainwater harvesting. This analysis has used different methods such as life cycle assessment (LCA), life cycle costing (LCC) and semi-quantitative assessments. Multiple integrated results were obtained both at the building and city scale. For example, we proved that the i-RTG and its flow exchanges with the building could help to save heating energy, waste generation, water consumption and CO2 emissions., Peer Reviewed, Postprint (author's final draft)

This is the peer reviewed version of the following article: [Petit‐Boix, A. , Arnal, C. , Marín, D. , Josa, A. , Gabarrell, X. and Rieradevall, J. (2017), Addressing the Life Cycle of Sewers in Contrasting Cities through an Eco‐Efficiency Approach. Journal of Industrial Ecology. . doi:10.1111/jiec.12649], which has been published in final form at https://doi.org/10.1111/jiec.12649. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving, Evaluating the sustainability of the urban water cycle is not straightforward, although a variety of methods have been proposed. Given the lack of integrated data about sewers, we applied the eco-efficiency approach to two case studies located in Spain with contrasting climate, population, and urban and sewer configurations. Our goal was to determine critical variables and life cycle stages and provide results for decision making. We used life cycle assessment and life cycle costing to evaluate their environmental and economic impacts. Results showed that both cities have a similar profile, albeit their contrasting features, that is, operation and maintenance, was the main environmental issue (50% to 70% of the impacts) and pipe installation registered the greatest economic capital expenditure (70% to 75%) due to labor. The location of the wastewater treatment plant (WWTP) is an essential factor in our analysis mainly due to the topography effects (e.g., the annual pump energy was 13 times greater in Calafell). Using the eco-efficiency portfolio, we observed that sewers might be less eco-efficient than WWTPs and that we need to envision their design in the context of an integrated WWTP-sewer management to improve sewer performance. In terms of methodological approach, the bidimensional nature of eco-efficiency enables the benchmarking of product systems and might be more easily interpreted by the general public. However, there are still some constraints that should be addressed to improve communication, such as the selection of indicators discussed in the article., Peer Reviewed, Postprint (author's final draft)

This paper describes a sustainability assessment methodology and example to select the best sustainable option from candidate conventional gravity and cantilever wall types and steel and polymeric soil-reinforced, mechanically stabilised earth (MSE) walls of different heights. Analyses were carried out using the value integrated model for sustainable evaluations (Mives) methodology, which is based on value theory and multi-attribute assumptions. The paper identifies how indicator issues are scored, weighted and aggregated to generate final numerical scores that allow solution options to be ranked. The final scores include an adjustment based on stakeholder preferences for the relative importance of the three sustainability pillars (environmental, economic and societal/functional). The analysis results show that MSE wall solutions were most often the best option in each category compared to conventional gravity and cantilever wall solutions and, thus, most often they were the final choice when scores from each pillar were aggregated to a final score. However, when cost was weighted most highly of the three pillars, then the conventional wall solutions gave the highest (best) Mives score for walls 3m high. If environmental issues were the most important concern of stakeholders, then the MSE solutions were the best solution, particularly for walls 5m high and higher., Peer Reviewed, Postprint (author's final draft)

Vertical farming is emerging as an effective measure to grow food in buildings and can increase food production in urban areas in a more sustainable manner. This study presents a comprehensive environmental assessment of food production in an integrated rooftop greenhouse (i-RTG) – an innovative vertical farm consisting of a rooftop greenhouse connected to a building – and considers rainwater, residual heat (energy), residual air (CO2) and food from an industrial ecology perspective. This synergistic connection preserves resources and improves conditions in the greenhouse and the building. The goal of the study is to show the feasibility of the system and to calculate the environmental impacts from its whole life cycle, from infrastructure to end of life, by comparing these impacts with those of conventional production. The results show that the system is feasible and produced 30.2¿kg/m2 of tomato over 15.5 months. The synergy with the building allows the cultivation of winter-fall crops without supplying heating and maintained an average temperature 8¿°C higher than that outdoors. Moreover, rainwater was used to irrigate the crops, reducing consumption from the water supply network by 80–90%. The environmental assessment showed that the operation of the i-RTG has more impacts than the infrastructure (structure of the greenhouse, rainwater harvesting system and equipment) due to the use of fertilisers, which account for 25% of the impacts in four of the six impact categories studied. Regarding the infrastructure, the greenhouse structure and rainwater harvesting system of the building have substantial environmental impacts (over 30% in four of the six impact categories). Comparison with a conventional greenhouse demonstrates that the i-RTG has a better environmental performance, showing between 50 and 75% lower impacts in five of the six impact categories (for instance, 0.58¿kg of CO2 equivalent per kg of tomato vs. 1.7¿kg), mainly due to the reduced packaging and t, Peer Reviewed, Postprint (author's final draft)

Water management plays a major role in any city, but applying alternative strategies might be more or less feasible depending on the urban form and water demand. This paper aims to compare the environmental performance of implementing rainwater harvesting (RWH) systems in American and European cities. To do so, two neighborhoods with a water-stressed Mediterranean climate were selected in contrasting cities, i.e., Calafell (Catalonia, Spain) and Ukiah (California, US). Calafell is a high-density, tourist city, whereas Ukiah is a typical sprawled area. We studied the life cycle impacts of RWH in urban contexts by using runoff modeling before (i.e. business as usual) and after the implementation of this system. In general, cisterns were able to supply > 75% of the rainwater demand for laundry and toilet flushing. The exception were multi-story buildings with roofs smaller than 200 m2, where the catchment area was insufficient to meet demand. The implementation of RWH was environmentally beneficial with respect to the business-as-usual scenario, especially because of reduced runoff treatment needs. Along with soil features, roof area and water demand were major parameters that affected this reduction. RWH systems are more attractive in Calafell, which had 60% lower impacts than in Ukiah. Therefore, high-density areas can potentially benefit more from RWH than sprawled cities., Peer Reviewed, Postprint (author's final draft)

Estudi de la interacció entre els diferents elements de les construccions analitzades (estructura, sòl i fonamentació superficial) per a diferents casos d'estudi en l'àmbit de l'enginyeria de terratrèmols, i obtenció de criteris de càlcul i projecte (desenvolupat en anglès).

Today, urban agriculture is one of the most widely used sustainability strategies to improve the metabolism of a city. Schools can play an important role in the implementation of sustainability master plans, due their socio-educational activities and their cohesive links with families; all key elements in the development of urban agriculture. Thus, the main objective of this research is to develop a procedure, in compact cities, to assess the potential installation of rooftop greenhouses (RTGs) in schools. The generation of a dynamic assessment tool capable of identifying and prioritizing schools with a high potential for RTGs and their eventual implementation would also represent a significant factor in the environmental, social, and nutritional education of younger generations. The methodology has four-stages (Pre-selection criteria; Selection of necessities; Sustainability analysis; and Sensitivity analysis and selection of the best alternative) in which economic, environmental, social and governance aspects all are considered. It makes use of Multi-Attribute Utility Theory and Multi-Criteria Decision Making, through the Integrated Value Model for Sustainability Assessments and the participation of two panels of multidisciplinary specialists, for the preparation of a unified sustainability index that guarantees the objectivity of the selection process. This methodology has been applied and validated in a case study of 11 schools in Barcelona (Spain). The social perspective of the proposed methodology favored the school in the case-study with the most staff and the largest parent-teacher association (social and governance indicators) that obtained the highest sustainability index (S11); at a considerable distance (45%) from the worst case (S3) with fewer school staff and parental support. Finally, objective decisions may be taken with the assistance of this appropriate, adaptable, and reliable Multi-Criteria Decision-Making tool on the vertical integration and imp, Postprint (author's final draft)

The aeronautic sector is a complex system where many stakeholders are involved. In this project is analyzed how are performed the Turnaround Processes (TAP) in El Prat Airport. These processes are the ones needed for attending the aircrafts during their scale, involving the use of fourteen different types of ground handling vehicles, classified as Light Duty Vehicles (LDV) or Heavy Duty Vehicles (HDV). As well, a characterization of the Land and Takeoff cycles (LTO cycles) performed in El Prat Airport is carried. The main objectives of this project are the quantification of the emissions generated by the ground handling vehicles and the aircrafts during 2017, and their associated environmental impact using the Simapro software. Then an alternative scenario is purposed, where the 19% of the ground handling vehicles are substituted by electric vehicles. A sustainability analysis using MIVES tool is carried, comparing the environmental, social and economic requirements between the actual scenario and the purposed one. The aircrafts are the main contributors in terms of emissions and environmental impact in comparison with the ground handling vehicles, accumulating a 97% of the total emissions and impacts. The contribution of the aircrafts is higher when the Green House Gases emissions and their associated impacts are analyzed. Oppositely, it decreases when the total polluting gases are compared. The main aircrafts performing LTO cycles in El Prat airport are the A320, the B738 and the A321. In proportion, this three aircrafts types represents a 70% of the total LTO cycles performed in El Prat airport, thus, they are the main contributors in terms of emissions and environmental impact. There aren’t notorious differences between the emission factors of each aircraft, so the total contribution is related to the percentage of aircraft types performing LTO cycles at the airport. Regarding at the ground handling vehicles, the main emission sources are the follow me vehicles

El sector de la construcción es el responsable de más de un 30% de las emisiones de CO2 y representa el 40% de la energía consumida en la Unión Europea. De la energía consumida por un edificio, más del 50% se destina a calefacción y refrigeración, poniendo de manifiesto la necesidad de construir edificios mejor aislados térmicamente y que a su vez generen un impacto ambiental lo más bajo posible. El presente trabajo estudia el impacto ambiental de tres alternativas de cerramiento exterior con diferentes aislamientos para un edificio de nueva construcción en Colloto, Asturias: fachada ventilada con ventanas de PCV de triple acristalamiento, fachada cara vista de doble hoja cerámica con ventanas de aluminio con rotura de puente térmico y doble acristalamiento, y fachada de una hoja cerámica con ventanas de aluminio sin rotura de puente térmico y doble acristalamiento. En el estudio se utiliza la metodología de Análisis de Ciclo de Vida y Coste de Ciclo de Vida con el fin de escoger aquella alternativa que presente un mejor impacto ambiental, considerando también su coste económico. La evaluación ambiental se realiza teniendo en cuenta indicadores de impacto intermedio y de impacto final. Se asigna al edificio un periodo de vida útil de 50 años. Los resultados obtenidos indican que, en todas las categorías de impacto final y en las categorías de impacto intermedio más relevantes, la alternativa que presenta un impacto ambiental más bajo es la fachada ventilada con ventanas de PVC y triple acristalamiento. El ahorro de energía durante la etapa de uso compensa el superior impacto ambiental de los materiales de construcción de dicha alternativa, otorgando una reducción del impacto respecto a la fachada de doble hoja de entre un 46% y un 50% para las categorías de daño final, y una reducción de entre un 56% y un 60% respecto a la fachada de una hoja. Finalmente, los resultados del estudio de costes muestran que la alternativa más económica es la fachada de doble hoja con u, El sector de la construcció és el responsable de més d’un 30% de les emissions de CO2 i representa el 40% de l’energia consumida a la Unió Europea. De l’energia consumida per un edifici, més del 50% es destina a calefacció i refrigeració, fent palès de la necessitat de construir edificis millor aïllats tèrmicament i que a la vegada generin un impacte ambiental el més baix possible. El present treball estudia l’impacte ambiental de tres alternatives de tancament exterior amb diferents aïllaments per a un edifici de nova construcció a Colloto, Astúries: façana ventilada amb finestres de PVC i triple envidrament, façana cara vista de doble fulla ceràmica amb finestres d’alumini amb trencament de pont tèrmic i doble envidrament, i façana d’una fulla ceràmica amb finestres d’alumini sense trencament de pont tèrmic i doble envidrament. A l’estudi s’utilitza la metodologia d’Anàlisi de Cicle de Vida i Cost de Cicle de Vida amb l’objectiu d’escollir l’alternativa que presenti un millor impacte ambiental, considerant també el seu cost econòmic. L’avaluació ambiental es realitza tenint en compte indicadors d’impacte intermedi i d’impacte final. S’assigna a l’edifici un període de vida útil de 50 anys. Els resultats obtinguts indiquen que, en totes les categories d’impacte final i en les categories d’impacte intermedi més rellevants, l’alternativa que presenta un impacte ambiental més baix es la façana ventilada amb finestres de PVC i triple envidrament. L’estalvi energètic durant l’etapa d’ús compensa l’impacte ambiental superior dels materials de construcció d’aquesta alternativa, proporcionant una reducció de l’impacte respecte a la façana de doble fulla d’entre un 46% i un 50% per a les categories d’impacte final, i una reducció d’entre un 56% i un 60% respecte a la façana d’una fulla. Finalment, els resultats de l’estudi de costos mostren que l’alternativa més econòmica es la façana de doble fulla amb un cost total de cicle de vida de 442.045,54€. La façana ventilada supo, The construction industry is the responsible of more than a 30% of the CO2 emissions and represents the 40% of energy consumed in the European Union. Analysing the consumed energy, more than a 50% is consumed by heating and cooling equipment, revealing the importance of build better thermally isolated buildings and at the same time with an environmental impact as low as possible. The current project studies the environmental impact of three building envelopes alternatives for a new building in Colloto, Asturias: ventilate façade with PVC windows and triple glazing, double-skin brick façade with aluminium windows with thermal break and double glazing, and brick façade with aluminium windows without thermal break and double glazing. This study uses the Life Cycle Analysis and Life Cycle Cost Analysis methodologies to choose the alternative with a better environmental impact, considering also its economic cost. The environmental assessment is done considering midpoint impacts and endpoint impacts. The building has 50 years of useful life. The obtained results show that, in all endpoint categories and in the most relevant midpoint categories, the alternative with a better environmental impact is the ventilate façade with PVC windows and triple glazing. The energy saving during the use stage compensates the higher impact of the construction materials. The ventilate façade means approximately an impact saving between 46% and 50% comparing to the double-skin brick façade for endpoint categories, and between 56% and 60% comparing to the brick façade. Finally, the Life Cycle Cost Analysis results show that the double-skin brick façade is the most economical one with a total cost of 442.045,54€. The ventilate façade has a cost increment of 0,94% (446.232,37€) and the brick façade a cost increment of 6,3% (472.798,39€). However, comparing the environmental impact and the economic costs of the ventilate façade and the double-skin brick façade for the global warming category, it

This paper extends the numerical parametric study previously reported by the writers for the vertical load distribution and vertical gap compression between facing panel units in steel reinforced soil walls ranging in height from 6 m to 24 m. The presented study demonstrates how gap compression and magnitude of vertical load transmitted between horizontal joints are influenced by joint location along the height of the wall, joint compressibility, and backfill, and foundation soil stiffness. The charts provided can be used to make a preliminary estimate of the number and type (stiffness) of the bearing pads to ensure a target minimum gap thickness at the end of construction, demonstrate the relative influence of wall height and different material component properties on vertical load levels and gap compression, or used as a benchmark to test numerical models used for project-specific design., Postprint (published version)

Life cycle assessment (LCA) is recognised as a powerful technique to determine the environmental impact component of sustainability assessments of structures in civil engineering projects at the time of design. This paper explains the principal parts and stages in an LCA methodology and demonstrates the approach using the examples of two conventional retaining wall types (gravity and cantilever type) and two mechanically stabilised earth (MSE) wall solutions using steel and polymeric soil reinforcement. The analyses include structures built to four different heights. The LCA methodology was able to quantitatively distinguish between the component environmental impacts of different wall solutions and thus provide a practical numerical score-based tool for designers to choose between candidate solutions. The MSE wall solutions resulted in lower environmental impacts than gravity and cantilever wall solutions as measured by global warming potential, cumulative energy demand, six major midpoint environmental indicator categories, three endpoint damage categories and in terms of overall endpoint scores. The target audiences for this paper are geotechnical and structural engineers engaged in the design of earth retaining wall structures but are less familiar with recent developments in LCA and how LCA can be linked to the design of these systems., Peer Reviewed, Postprint (author's final draft)

El objetivo de este trabajo es realizar un análisis de ciclo de vida sobre dos técnicas de cultivo de piña: el sistema tradicional con suelo desnudo y cielo abierto y el sistema tecnológico con uso de acolchado plástico y malla sombra. La mayor parte de siembra de piña en México es en el estado de Veracruz. Por está razón los productores de esta región proporcionarán datos de campo mediante la respuesta a una encuesta., La agricultura es una de las actividades que emiten gases de efecto invernadero (GEI) y contribuye alrededor del 10-12% del total de emisiones antropogénicas de dichos gases. El crecimiento acelerado de la población trae consigo una fuerte demanda en los mercados locales y de exportación de la piña (Ananas comosus). Por ello, se hace necesario buscar estrategias o alternativas para los sistemas de producción agrícolas. En los últimos diez años en México, principalmente en la Región del Papaloapan y la Chontalpa, se han utilizado dos sistemas de manejo para el cultivo de piña totalmente contrastantes. El sistema Convencional basa la producción en suelo desnudo y cielo abierto, mientras el sistema Ambiente Protegido se fundamenta en proteger al suelo, la humedad y las plantas con los frutos, mediante el uso del acolchado plástico total y la malla-sombra. El sistema de manejo de Ambiente Protegido fue desarrollado por el Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), a través de su Campo Experimental Papaloapan, reportando que, mediante estas técnicas se acortan de 2 a 3 meses los ciclos de cultivo, mayor rendimiento y productividad, evita que salgan malezas y se reduce la aplicación de insumos y agroquímicos. En los sistemas de manejo utilizados para la producción intensiva de piña fresca de exportación se aplican de manera intensiva, insumos como herbicidas, plaguicidas, hormonas y fertilizantes químicos. El presente estudio se realizó para analizar y comparar los sistemas de manejo para la producción de piña, mediante una encuesta realizada a 3 grandes empresas que se dedican a su cultivo y comercialización. De esta forma fue posible contabilizar los insumos utilizados en todas las actividades involucradas en el proceso de producción y se obtuvo el inventario. La metodología del Análisis del Ciclo de Vida (ACV) nos ha permitido caracterizar ambientalmente los dos sistemas de manejo para la producción de piña. Los resultados indican, Agriculture is one of the main activities that emits greenhouse gases (GHG), with a contribution of around 10-12% of the total anthropogenic GHG emissions. The fast growing population brings with it a strong demand in the local and export markets of pineapple (Ananas comosus). Therefore, it is necessary to look for strategies or alternatives for agricultural production systems. In the past ten years in Mexico, mainly in the Region of Papaloapan and the Chontalpa, it two totally contrasting management systems have been used for pineapple agriculture. The “Conventional System” bases production on bare ground and open sky, while the “Protected Environment System” is based on protecting the soil, moisture and plants with the fruits, through the use of total plastic mulching and shade cloth. The Protected Environment management system was developed by the National Institute of Forestry, Agriculture and Livestock Research (INIFAP), through its Papaloapan Experimental Field, reporting that these techniques shorten the crop cycles by 2 to 3 months, gets higher yield and productivity, prevents weeds from growing and reduces the application of inputs and agrochemicals. In the management systems used for the intensive production of fresh export pineapples, inputs such as herbicides, pesticides, hormones and chemical fertilizers are intensively applied. The present study was carried out to analyze and compare management systems for pineapple production, through a survey of 3 large companies engaged in the cultivation and commercialization of pineapples, it was possible to account for the inputs used in all the activities involved in the production process, this way the inventory was gathered. Life Cycle Analysis (LCA) methodology has allowed us to characterize the two management systems for the production of pineapple. Results indicate that, in all cases of the 18 evaluated impact categories, the Protected Environment system has a lower environmental impact. The production of 1

Stormwater management is essential to reducing the occurrence of flooding events in urban areas and to adapting to climate change. The construction of stormwater Best Management Practices (BMPs) entails a series of life cycle environmental impacts but also implies avoided burdens, such as replacing urban infrastructure after flooding. The aim of this paper is to integrate flood damage prevention into the life cycle assessment (LCA) of BMPs for quantifying their net environmental impact (NEI) and environmental payback (EP) from a consequential LCA standpoint. As a case study, the application of a filter, swale and infiltration trench (FST) in a Brazilian neighborhood was assessed considering a high-intensity rainfall event. The potential avoided impacts were related to cars and sidewalks that were not destroyed due to flooding. In terms of CO2eq. emissions, the environmental investment related to the FST was recovered when the destruction of one car or 84 m2 of sidewalk was prevented. The NEI of the FSTs resulted in significant impact reductions (up to 700%) with respect to not accounting for the avoided products. This approach can be implemented to any type of BMP, and more accurate estimations can be made with data for different events and different types of material damage., Peer Reviewed, Postprint (author's final draft)

The integration of rooftop greenhouses (RTGs) in urban buildings is a practice that is becoming increasingly important in the world for their contribution to food security and sustainable development. However, the supply of tools and procedures to facilitate their implementation at the city scale is limited and laborious. This work aims to develop a specific and automated methodology for identifying the feasibility of implementation of rooftop greenhouses in non-residential urban areas, using airborne sensors. The use of Light Detection and Ranging (LIDAR) and Long Wave Infrared (LWIR) data and the Leica ALS50-II and TASI-600 sensors allow for the identification of some building roof parameters (area, slope, materials, and solar radiation) to determine the potential for constructing a RTG. This development represents an improvement in time and accuracy with respect to previous methodology, where all the relevant information must be acquired manually. The methodology has been applied and validated in a case study corresponding to a non-residential urban area in the industrial municipality of Rubí, Barcelona (Spain). Based on this practical application, an area of 36,312 m2 out of a total area of 1,243,540 m2 of roofs with ideal characteristics for the construction of RTGs was identified. This area can produce approximately 600 tons of tomatoes per year, which represents the average yearly consumption for about 50% of Rubí total population. The use of this methodology also facilitates the decision making process in urban agriculture, allowing a quick identification of optimal surfaces for the future implementation of urban agriculture in housing. It also opens new avenues for the use of airborne technology in environmental topics in cities., Postprint (author's final draft)