•Optimising insulation thickness for the building’s envelope.•Eco-efficiency analysis of life cycle and cost assessment.•Sensitivity analysis by varying the building’s energy demand ...scenarios.•Emerging naturally-based insulation materials were the most eco-efficient.
Thermal insulation materials play an important role in the challenge of nearly zero-energy buildings thanks to their potential in reducing building’s energy demand and carbon emissions. However, increasing the thickness of the insulation material in the building’s envelope has implications from the energy, environmental and economic viewpoints. In this context, efforts should be made to optimise insulation thickness to balance all these aspects.
This study presents a methodology to analyse optimum insulation material for the building’s envelope (roof, façade and floor) and its thickness to achieve energy demand reductions in the operation phase of the building, which is based on the Life Cycle Assessment and Life Cycle Costing methodologies to integrate both environmental and economic aspects, respectively. The system boundary includes the life cycle stages of product and use defined by recent European standards. A selection of eleven alternative insulation materials, both conventional and emerging ones based on natural products, were chosen to conduct the study. After applying the methodology to a single-family house in Spain and performing a sensitivity analysis, the results revealed that sheep wool and recycled cotton, jointly with traditionally used mineral and glass wool, should be promoted in the construction industry as they offer the highest eco-efficient performance among the analysed insulation materials. Reductions of up to 40% in energy demand compared to regulations standards can be achieved in theeco-efficiency context.
This study presents a methodology that allows the analysis of how an existing product design meets the design guidelines required from the circular economy perspective, and which are the design ...guidelines that would need to be incorporated into its design to become a better circular design product. For that, as a starting point, the design guidelines required for the circular product design have been identified from an extensive literature review. Then, criteria have been defined to measure the margin of improvement of a product design based on the level of compliance of each circular design guideline, and the relevance of each circular design guideline for the specific product category to which it belongs. Finally, the methodology has been applied to a representative sample of 127 appliances belonging to different categories of small household electrical and electronic equipment. The circular design guidelines related to extending life span and to product/components reuse have been identified as those that more urgently need to be incorporated, while the urgency of those related to connectors or product structure is moderate.
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•This research reviews design guidelines from the perspective of circular economy.•A methodology is proposed for evaluating the level of circularity of products.•The paper introduces a case study on 127 small electrical and electronic equipment.
Although methodological development of Life Cycle Sustainability Assessment (LCSA) is still under discussion, an increasing number of case studies have been published in recent years. A necessity to ...strengthen methodological trade-offs and obtain a consistent basis for future LCSA case studies exists. The aim of this research is to identify how LCSA is being applied for each of the pillars of sustainability (environmental, economic and social) and how results are being integrated into the decision-making process. To achieve this aim, a systematic review of case studies was conducted. The methodology followed includes research questions to guide the process, search guidelines for selecting case studies to analyse and assessment rules to identify information to extract. The descriptive and content analyses of case studies provided key findings related to the main goals, divergences in the scope of the pillars of sustainability, data collection sources, the most readily applicable impact indicators for each of the three pillars of sustainability, operational research methods applied as drivers for communication and decision processes. In addition, the incipient interactions between LCSA and new sustainability approaches as circular economy and Sustainability Development Goals (SDG) is analysed. As a final conclusion, further research should be carried out to achieve consistency in the selection of the scope for each pillar of sustainability. This would make it possible to develop more accurate indicators for quantifying the social impact and to point out advantages and disadvantages of operation research methods for communication and support in decision-making.
•100 LCSA case studies have been analysed (descriptive and content).•Goal, scope, inventory data and indicators analysed for each sustainability pillar.•Consistency is needed when selecting the scope for each sustainability pillar.•Methodological framework for defining social indicators is in progress.•Research is needed to communicate sustainability indicators.
Higher Education Institutions (HEI) or universities, as organisations engaged in education, research and community services, play an important role in promoting sustainable development. Therefore, ...they are increasingly linked to the initiative of calculating their carbon footprint (CF), which is a tool to assess sustainability from the perspective of greenhouse gas (GHG) emissions. The aim of this study is to carry out a systematic review of the current situation of CF assessment in academic institutions by analysing different key elements, such as the time period, methodologies and practises, calculation tools, emission sources, emission factors and reduction plans. The review protocol considered articles published until March 2021. Of the articles reviewed, 35 are aimed specifically at calculating the CF of HEI, while the remaining articles consist of review, activity-specific CF assessment or GHG emission reduction articles. Clear differences have been identified when results are compared for the normalised CF (average of 2.67 t CO
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e/student, ranging from 0.06 to 10.94) or the percentage of carbon offsetting, only considered in 14% of the studies and ranging from 0.09 to 18%. The main reason for this is the lack of standardisation as regards the time metric (year, semester), functional unit (student, employee, area) and data collection boundary (scope 1, 2, 3), the emissions sources and emission factors, mainly for scope 3 (water consumption and treatment, waste treatment, office, ICT and laboratory consumables, commuting and travel, construction materials, canteens, etc.), and the inclusion or not of the effect of carbon offset projects to offset the CF (aim of the project and absorption sources and factors). However, despite the differences, a reduction over time is clearly observed. Therefore, CF in HEI requires further improvements and solutions to a number of challenges, including the definition of representative emission sources, the creation of a robust emission factor database and the development of tools/methodologies that cover all the needs of this type of organisation.
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The use of tools capable of evaluating the sustainability of buildings throughout their life cycle represents a key point enabling the transition towards a sustainable built environment. To this end, ...different Green Building Rating Systems (GBRS) have been developed over the last few decades. All of them are voluntary schemes and propose a set of indicators to evaluate the associated impacts of buildings throughout their life cycle. However, it is unclear how GBRS are addressing sustainability dimensions and the life cycle frameworks, and particularly in residential buildings, which are responsible for a great part of these impacts. The aim of this study is to explore, in detail, how indicators in GBRS are covering the three dimensions of sustainability (environmental, social and economic) and the information modules proposed by EN 15978, along the life cycle stages of the building construction process. To do so, eight GBRS were selected and the 387 sustainability indicators included in them were analysed and clustered according to three different classification criteria, namely, sustainability dimension, information modules and stage of the construction process life cycle. The analysis and clustering process of indicators was carried out by a panel of experts in the field of study, with multidisciplinary academic and professional background, throughout an iterative process of four rounds and meetings, which led to achieve a consensus in the findings. The results of the analysis revealed that the environmental dimension is the one that is considered most among the tools, and both the social and economic dimensions require more attention to achieve a good balance. GBRS are more focused on the evaluation of the embedded impacts of the building, since most of the indicators are related to the product and construction stages (A1-A5) and therefore need to acquire a more holistic approach throughout the whole life cycle; the indicators should be considered in the very early design stage (not when the building is in operation), when decisions are made and have more potential to improve the sustainability performance of the buildings throughout its lifespan. It was not possible to cluster one set of indicators as they referred to aspects beyond the EN 15978 system boundary (such as site, transport or domestic waste management), thus highlighting the need for more coherence between a building's life cycle and GBRS frameworks, on the one hand, and the inclusion of new information modules covering the above-mentioned additional aspects, on the other.
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•Eight GBRS and 387 sustainability indicators were comprehensively analysed.•The three sustainability's dimensions require to be more balanced in GBRS.•GBRS should be applied from the early design stage of the building to succeed.•Life cycle information modules in EN 15978 fail to cover all aspects in GBRS.
This study presents a methodology designed for selecting, from an environmental point of view, the best end-of-life scenario for electric and electronic equipment which breaks before the end of its ...life span. To this end, the environmental impact of the life cycle of the equipment is evaluated for two different end-of-life scenarios: repair & reuse vs. replacement. As a case study, the proposed methodology is applied to a representative sample of nine categories of small household electric and electronic equipment (120 appliances). Repair & reuse scenarios consider the life span and the typical failures and repairs associated with each electric and electronic equipment category and the use of the repaired equipment until the remaining life span after its breakage. Replacement scenarios also consider the life span associated to each electric and electronic equipment category and the replacement of the broken equipment by an equivalent during the remaining life span after its breakage. The environmental impact obtained for both scenarios for each small household electric and electronic equipment category is compared in order to identify the best end-of-life scenario. To do so, the life cycle assessment methodology is applied, using CML and ReCiPe as midpoint- and endpoint-impact assessment methods, respectively. The results indicate that for all the analysed categories, the repair & reuse scenarios generally prove environmentally better than replacement scenarios, as Directive 2012/19/EU promotes. However, for some types of failure, e.g. those related to motors or printed circuit boards, if the failure occurs at the end of its life span, replacement is a better option than repair & reuse, since the environmental impact of the repair activities is not offset by the environmental benefits of extending the useful life until the end of the life span.
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•Repair & reuse option is analysed against replacement option for the EoL of EEE.•Nine categories of small household EEE are analysed.•Different repair types are considered for each EEE category.•Repair & reuse option generally proves environmentally better than replacement.•For certain repair types, replacement is the best option.
•Habits and practices towards the storage, repair and second-hand purchase of small ICT devices have been identified.•A survey conducted to a representative sample (95%confidence level and 5%margin ...of error)•73.9% of the respondents store disuse small ICT devices at home.•65.5% of the respondents have never taken to repair broken small ICT devices.•87.6% of the respondents have never purchased second-hand never bought second-hand small ICT devices.
This study analyses the current habits and practices towards the store, repair and second-hand purchase of small electrical and electronic devices belonging to the category of information and communication technology (ICT). To this end, a survey was designed and conducted with a representative sample size of 400 individuals through telephone interviews for the following categories: MP3/MP4, video camera, photo camera, mobile phone, tablet, e-book, laptop, hard disk drive, navigator-GPS, radio/radio alarm clock. According to the results obtained, there is a tendency to store disused small ICT devices at home. On average for all the small ICT categories analysed, 73.91% of the respondents store disused small ICT devices at home. Related to the habits towards the repair and second-hand purchase of small ICT devices, 65.5% and 87.6% of the respondents have never taken to repair and have never purchased second-hand, respectively, small ICT devices. This paper provides useful and hitherto unavailable information about the current habits of discarding and reusing ICT devices. It can be concluded that there is a need to implement awareness-raising campaigns to encourage these practices, which are necessary to reach the minimum goals established regarding preparation for reuse set out in the Directive 2012/19/EU for the category small electrical and electronic equipment.
This study presents a survey to identify current habits and practices regarding the repair and second-hand purchases of small household electrical and electronic equipment (EEE) in Spain, and to ...identify the profile of consumers who are more or less prone to this behaviour. To this end, a survey was designed and conducted with a representative sample size of 400 valid responses obtained through telephone interviews. It allowed the identification of the most frequent small EEE in households, and consumer habits as regards replacement, repairs and second-hand purchases. Consumers used small household EEE for an average of 6.25 years; 9.56% of those interviewed had never repaired broken small household EEE, and only 0.75% had bought second-hand small household EEE at some time. The analysis of the relationship between consumer attitudes and their socio-economic characteristics using logit models indicated that older consumers and females were more prone to repair small household EEE, while older males with medium family incomes tended to purchase second-hand small household EEE more. Finally, consumers indicated that they considered it is important that the design and labeling of small household EEE included aspects and information about their durability. The obtained results are useful for designing and targeting future awareness campaigns to proper audiences that promote extending the lifetime of EEE by repairing and second-hand purchases. These actions can help to achieve the minimum recovery targets for preparing for the reuse stated within the waste policy framework.
•Habits and practices towards the repair and second-hand purchase of small household EEE have been identified.•A survey conducted to a representative sample (95% confidence level and 5% margin of error).•9.56% of the respondents have ever repaired broken small household EEE.•0.75% of the respondents have ever bought second-hand small household EEE.
The upward trend in the residential sector of energy use has significant consequences in terms of environmental impacts. Determining the carbon metric (CM), as part of the whole carbon footprint of a ...building, contributes to quantify the carbon emissions related to the building's use stage. Although many carbon footprint calculators exist in other sectors, none has been specifically designed and applicable to the building one. However, ISO 16745 provides guidelines for calculating and reporting the CM of existing buildings in operation. In this context, this work sets a methodology to measure the CM of existing households' use stage, based on ISO 16745 and split into three stages. The implementation of the methodology to a case study proved its applicability since it enabled the data collection task through the designed survey, and allowed the energy carriers and end-uses be disaggregated, quantified and clearly reported for user's knowledge. The study outlined that calculating the CM and, more specifically, reporting and making the results publicly available, help raise users' awareness about reducing greenhouse gas-related emissions, and provide new ideas for monitoring, benchmarking and proposing policies at individual member state and EU levels.
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•Carbon metric calculation and reporting of households' use stage.•Methodology based on International Organization for Standardization 16745:2017.•Proposal of a survey for data collection and a disclosure report template.•Energy use data collection from household's actual consumption.•Contribution to users' awareness on reducing household emissions-related.
Green Public Procurement (GPP) plays an important role in facing the challenge of reducing the environmental impacts from construction sector-related products, services and works, and creating ...environmental and innovative value for society in favour of a greener and more sustainable economy. The European Commission recently developed GPP criteria for the “office buildings” category. In parallel, Building Sustainability Assessment (BSA) tools help estimate a building's impact on the environment based on a life cycle approach. Many of the aspects and measurable indicators included in BSA tools are clearly related to the criteria covered by GPP. However, other important ones are missing and should be integrated to ensure green procurement initiatives. This study critically reviews the GPP criteria proposed for office buildings and crosschecks them with the sustainability indicators included in three BSA tools to reinforce the GPP framework for the office buildings sector. It provides, on the one hand, an evaluation of the rate of improvement achieved in the tools when applying GPP criteria and, on the other, a proposal for a weighting system for awarding points to the offers in tenders. The results will help contracting authorities to introduce more objectivity into the tendering process and to make informed decisions while evaluating bidders' proposals.
•Integration of Green Public Procurement and Sustainability office buildings' criteria•Gap analysis of topics and criteria covered reveal strong relationship•Applying Green Public Procurement on building tools provides optimum rating levels.•Energy in Green Public Procurement should be given a weight ranging of 20–28%.•Transport, life cycle, water, daylighting and global warming should be also boosted.
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