Dr Jaume Albertí, head of the Sustainable Construction line of research:

"In the future, we will have to analyse how to apply current LCA methods not just to a set of buildings but also to more complex systems such as cities. We will need a fresh perspective, since cities can’t be viewed merely as an assemblage of products and buildings but rather as more complex systems that call for a more holistic approach."


We help share best available techniques and practices on the Construction21 online platform for sustainable construction, which is managed in Spain by the Chair. We have also worked with private-sector companies (Hyspalit) as well as manufacturers of ancillary (BNL) or urban furniture products (JCDecaux).

Key papers

Appropriate selection of construction materials plays a major role in a building's sustainable profile. The study sets out a comparative life cycle assessment of indoor flooring systems of different nature. The flooring systems consisted of coverings and, where required, bonding material and/or impact soundproofing material. The following coverings were assessed: inorganic (natural stone and ceramic tiles), polymer (carpeting and PVC), and wood-based (laminate and parquet) coverings. The life cycle assessment scope was defined cradle to cradle, i.e. product stage, transport to the construction site, installation of all construction elements, use, and valorisation by recycling, as end-of-life transition scenario towards a circular economy. In the use stage, three scenarios were defined as a function of pedestrian traffic intensity, which determined maintenance, repair, and replacement operations and frequencies. The environmental impacts of the coverings product stage were taken from previously assessed and selected Environmental Product Declarations (EPDs), as these are standardised public documents devised to provide environmental life cycle information. The method adopted in the study suggests that, though the use of EPDs as information source is interesting, erroneous conclusions may be drawn if the EPDs are not comparable and/or if the comparison is not made in the building context. The results indicate that the flooring systems with inorganic coverings performed best in the global warming, acidification, eutrophication, photochemical ozone creation, and abiotic depletion for fossil resources impact categories, whereas laminates performed best in the abiotic depletion for non-fossil resources and ozone layer depletion impact categories. The carpet flooring system performed worst in every impact category except photochemical ozone creation potential.

Solar thermal energy is considered a ‘clean’ form of energy; however, environmental impacts occur during its life-cycle. The present work compares the environmental performance of two scenarios: a solar thermal system for providing domestic hot water (DHW) used in conjunction with a traditional natural gas heating system, and the natural gas heating system on its own. Weak points are found and different eco-design scenarios are evaluated in order to achieve a more circular economy. In addition, the authors explore what would be the national Greenhouse Gas emission reduction potential of a wider use of domestic solar hot water systems (DSHW) in China’s and Spain’s built environment. In this case, five displacement methods are suggested to show how the emissions reduction vary.

Through a review of the state of the art and a Life Cycle Assessment of a solar system the two scenarios are assessed. Some impact categories, such as global warming, suggest a markedly better performance of the solar system (-65%). However, weak points in the solar solution have been identified as there is an increase of impacts in cases such as acidification (+6%) and eutrophication (+61%), mostly due to the metals used. The components with higher environmental impact are the collector, the tank, and the copper tubes.

The reduction of national emissions by promoting DSHW depends on the actual displaced technology/ies. The consequences on national emissions reduction depending on these choices are assessed. The potential reduction of emissions, if 30% of the DHW were covered with solar sources, would be between 0.38% and 0.50% in the case of Spain and between 0.12% and 0.63% in China.


The goal of this article is to find out if an old Life Cycle Assessment (LCA) study remains valid or not after a period of time. To answer this we re-perform an LCA of a bus stop in the city of Barcelona that was performed about 20 years ago.


The LCA of a bus stop, performed and published in 1998, is re-performed and its results compared with those of the original study, keeping the same scope of the original system. The software used by the original study was SimaPro; the data came from IVAM LCA data, BUWAL 250, IDEMAT 96 and PRe4 databases; and CML 1992 impact assessment methodology was used. The new study used thinkstep GaBi6 software; GaBi6 Professional + extension databases; and CML 2001 methodology. The assessment includes an analysis of the key influencing factors that cause the discrepancies, such as models and databases. Moreover, a specific focus on evolution of the methodologies and its influence on the results is described. A 30% of difference between results is accepted as the threshold value to be able to state that the results differ.

Results and discussion

The overall results obtained in the two studies are quite similar or, at least, comparable. However, when analysing and comparing the systems disaggregated stage by stage, higher differences in each impact category are found. Therefore, the lower discrepancy at system level may be due to coincidence or compensation. The main causes of discrepancy have been found to be: (i) the update of the assessment methodologies and characterization factors, (ii) the improvement of the databases, and (iii) the change in the techno-sphere and the improvement of the environmental policies.

Conclusions and recommendations

After 15–20 years, LCA results cannot be considered reliable. Results can, however, be used as an indication for the expected order of magnitude of the impacts and for the relative importance of the processes in the different life cycle stages. The comparison is made through one case study only; therefore, it can barely be used as a generalization, neither for the difference in results nor for the sources of discrepancy. Nevertheless, this type of analysis can be considered a first step in quantifying the longevity of LCA results.

Research on Life Cycle Assessment (LCA) was initially performed to analyze specific products; however, it evolved to assess environmental impacts of more complex systems, such as roads. In this, the construction, use and maintenance stages are usually considered. The results of different studies revealed that all stages have relevant environmental impacts like topsoil loss, change in the use of land, modification of natural drainage and groundwater patterns, landslides, erosion, sedimentation, landscape degradation, increase in noise and dust levels, fuel and oil spills, waste generation, and air, soil and water pollution.

This paper presents the results of a literature review on the application of LCA in road construction as a tool to quantify the potential impacts derived from the use of traditional and alternative materials. The research showed that the most common materials found were recycled asphalt (concrete and bitumen), fly ash, and polymer. In addition, the environmental impact categories more commonly assessed were energy consumption and global warming potential (GWP). These results claimed that the construction of roads should be directed towards the fulfilment of technical, social, economic and environmental criteria. Finally, it was found that most of the studies were performed for high traffic volume roads; therefore, for developing countries, research is needed focussed on low traffic ones.


Porcelain stoneware tile (PST) is currently the ceramic tile of greatest commercial and innovation interest. An environmental life cycle assessment of different varieties of PST was undertaken to enable hotspots to be identified, strategies to be defined, differences between PST varieties to be evaluated and guidance for PST manufacturers to be provided in choosing the Environmental Product Declaration (EPD) programme that best suited their needs according to grouping criteria.


Analysis of previous information allowed three main parameters (thickness, glaze content and mechanical treatment) to be identified in order to encompass all PST variations. Fifteen varieties of PST were thus studied. The coverage of 1 m2 of household floor surface with the different PST varieties for 50 years was defined as functional unit. The study sets out environmental data whose traceability was verified by independent third parties for obtaining 14 EPDs of PST under Spanish EPD programmes.

Results and discussion

The study presents PST inventory analysis and environmental impact over the entire life cycle of the studied PST varieties. The natural gas consumed in the manufacturing stage accounted for more than 70% abiotic depletion–fossil fuels and global warming; electricity consumption accounted for more than 60% ozone layer depletion, while the electricity generated by the cogeneration systems avoided significant environmental impacts in the Spanish power grid mix. The variations in PST thickness, amount of glaze and mechanical treatments were evaluated. The PST variety with the lowest environmental impact was the one with the lowest thickness, was unglazed and had no mechanical treatments. Similarly, the PST variety with the highest environmental impact was the one with the greatest thickness, was glazed and had been mechanically treated.


The PST life cycle stage with the highest environmental impact was the manufacturing stage. The main hotspots found were production and consumption of energy and raw materials extraction. Variation in thickness was a key factor that proportionally influenced almost all studied impact categories; the quantity of glaze strongly modified abiotic depletion–elements and eutrophication, while the mechanical treatments contributed mainly to ozone depletion. The study of all PST varieties led to the important conclusion, against the current trend, that differences among them were found to be so significant that declaring a number of PSTs within the same EPD is not directly possible, and it needs preliminary verification to ensure compliance with the product category rule.

Key projects

Este documento de orientación es el resultado de la colaboración entre expertos en enfoque de ciclo de vida y turismo sostenible del ámbito de la academia, organizaciones internacionales y asociaciones industriales.

El objetivo principal del proyecto es promover la sostenibilidad de los destinos turísticos. Los principales resultados del proyecto incluyen el desarrollo de una metodología que incluye la combinación de ACV y tablas input-output para llevar a cabo evaluaciones de sostenibilidad de estos destinos, la selección de indicadores y la realización de una prueba piloto de la metodología.

El objetivo principal del proyecto es identificar las mejores prácticas relacionadas con los Edificios de consumo energético casi nulo (en inglés, Net Zero Energy Buildings, NZEB) y las soluciones de industrialización aplicadas a edificios en España y Francia, identificando los principales desafíos y oportunidades en relación con la aplicación de la Directiva 2010/31/UE del Parlamento Europeo y del Consejo sobre la eficiencia energética en los edificios. El resultado principal del proyecto incluye la creación de una plataforma euroregional y virtual en España, Francia y en el resto del ámbito europeo, para debatir las mejores prácticas relacionadas con la industrialización de los Edificios de consumo energético casi nulo y recopilar casos de estudio y productos.

El objetivo principal del proyecto es promover la eficiencia de los recursos y la reducción de los impactos ambientales asociados a la gestión urbana durante todas las fases de su ciclo de vida y también promover el uso de la metodología ACV. El resultado principal del proyecto incluye el desarrollo de una herramienta de software de ACV, en línea y gratuita, para la evaluación de los impactos relacionados con la energía y el consumo de agua de zonas urbanas de Francia, España y Portugal.

El objetivo principal del proyecto consiste en la construcción de una colaboración estratégica a largo plazo a través de las instituciones de enseñanza superior para mejorar la capacidad institucional y de investigación, en general, en términos de calificaciones académicas y prácticas de enseñanza. En particular, el proyecto tiene como fin desarrollar e implementar un programa de Másters sobre procedimientos innovadores de análisis de participación integrada de la viabilidad y conveniencia de los sistemas de energía en relación con la especificidad de los diferentes contextos socioeconómicos y geográficos.

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UNESCO Chair in Life Cycle and
Climate Change ESCI-UPF

Passeig Pujades 1, 08003
Barcelona, España
(+34) 93 295 4710

2024-06-25 15:25:18