The construction sector plays an important role in moving towards a low-carbon economy. Life cycle assessment (LCA) is considered one of the most effective methods of analytically evaluating environmental profiles and an efficient tool for calculating the environmental impacts in building design-oriented methodologies, such as building information modelling (BIM). At early design stages, generic LCA databases are used to conduct the life cycle inventory (LCI), while detailed stages require more detailed data, such as environmental product declarations (EPDs), namely documents that provide accurate results and precise analyses based on LCA. Limitations are recognized when using EPDs in BIM elements at different levels of development (LOD) in the design stages, especially related to the data consistency and system boundaries of the LCA. This paper presents a method of achieving accurate LCA results, that helps with decision-making and provides support in the selection of building products and materials. The method is validated by its application in the structural concrete of an office building located in Germany. The method defines a safety factor adopted for embodied impacts (“cradle-to-gate”), based on EPD results to predict the environmental impact of BIM elements at different LODs. The results obtained show that by integrating the method to conduct the LCA, the range of errors and possible inconsistencies in the LCA results can be reduced.

This study aims to examine the feasibility of using environmental product declarations (EPDs) as a data source for life-cycle assessment (LCA) in two sustainable building assessment schemes–the pilot version of the European framework Level(s) and the German system DGNB (Deutsche Gesellschaft für Nachhaltiges Bauen). An EPD is a standardized and third-party certified label to communicate product-specific environmental data based on LCA. Some green building rating systems consider it a robust LCA data source and encourage its use over generic data. This work evaluates the environmental profile of the envelope of an office building in the context of level(s) and DGNB adopting EPD as a data source. The results indicate that the EPDs did not cover the mandatory scope of the schemes. Furthermore, there was a lack of EPDs appropriate to the geographical context of the case study, leading to the adoption of EPDs of products from places other than the building site and an overestimation of the environmental impacts of transportation. Moreover, the need for EPDs considering suitable and comprehensive scenarios as well as life-cycle stages beyond the product stage is highlighted. This gap, in fact, hinders the performance of a complete LCA within the analyzed building assessment schemes when relying solely on EPDs as a data source. With this paper, we wish to encourage the further development of EPDs related to the integration of more life-cycle modules and more comprehensive scenarios, considering the direction of the latest amendment of the ISO 15804 for EPDs of construction products.

The decarbonization of the construction sector, which is one of the most impactful sectors worldwide, requires a significant paradigm shift from a linear economy to a circular, future-proofed and sustainable economy. In this transition, the role of designers and structural engineers becomes pivotal, and new design objectives and principles inspired by Life Cycle Thinking (LCT) should be defined and included from the early stages of the design process to allow for a truly sustainable renovation of the built environment. In this paper, an overview of LCT-based objectives and principles is provided, critically analyzing the current state of the art of sustainability and circularity in the construction sector. The effectiveness of applying such design principles from the early stages of the design of retrofit interventions is then demonstrated with reference to a case study building. Four seismic retrofit alternatives made of timber, steel and concrete, conceived according to either LCT principles or traditional, were designed and compared to a demolition and reconstruction scenario on the basis of five common environmental impact indicators. The indicators were calculated adopting simplified LCA analyses based on Environmental Product Declarations (EPDs), considering the product and End of Life stages of the building. The results of the comparative analyses confirm that LCT-based retrofit solutions are less impactful than both the traditional seismic retrofit interventions and the demolition and reconstruction scenario.

The Life-cycle Assessment (LCA) method and the Environmental Product Declaration (EPD) each play a crucial role in reducing buildings’ embodied environmental impacts. EPDs provide the validated and geographically representative data necessary to conduct an LCA. However, the development of EPDs in the European context is still irregular. Countries such as Germany and France have many EPDs for construction products, while other countries, such as Spain, have a limited number of EPDs and more than one operator programme, which is pointed out in the literature as a possible limiting factor for comparing results. This study aimed to examine the use of construction product EPDs manufactured in Spain, to then use as a data source to conduct a building LCA. We analysed the comparability of the results among the different EPD programmes and investigated to what extent the use of Spainߣs geographically representative construction product EPDs can contribute to conducting a building LCA, including all the materials and products that compose a building, and covering all the building life-cycle stages (product, construction, use, and end-of-life). The results showed that plasterboard and thermal insulation products have the highest numbers of EPDs in different EPD programmes. The case study analysis showed that 20% of the construction products that compose a building can potentially use these EPDs as a data source to conduct a building LCA, and 89% of those product categories include at least the product, use, or end-of-life stage modules. Finally, recommendations and challenges to improve LCA development in the architecture, engineering, construction, and operation industries were included.

Scientific literature provides evidence that mitigating the effects of a building’s operation does not in itself ensure an overall improvement in its environmental performance. A Life Cycle Assessment (LCA) plays a key role in gauging the overall environmental performance of a building although several authors argue that the lack of LCA threshold values makes it difficult to compare design options or measure whether reduced impact targets are achieved. This has led the Green Building Rating Systems (GBRS) to include the LCA within their evaluation criteria and, in like Active House (AH), establish threshold values of the main impact categories to quantify the level of performance achieved. Since the reliability of the data sources is a crucial issue for applying the LCA method, the effectiveness of their implementation within the GBRS also strictly depends on the origin of the impact values. To quantify the extent to which the source affects the impacts calculated by the LCA threshold value in AH, the present study compared the outcomes of two assessments carried out in parallel using two different data sources: AH–LCA evaluation tool v.1.6 and the Environmental Product Declaration (EPD). A Passive House (PH)-compliant, small residential building was selected as a case study, as this is a standard that excels in ultra-low-energy performance. Moreover, given the crucial role that the envelope plays in the PH standard, the analysis was undertaken on the envelope of a PH-compliant building located in Northern Italy. To stress the influence of embedded effects in a Passive House, the assessment focused on the production and end-of-life stages of building materials. The comparison showed a relevant difference between the two scenarios for all the environmental indicators: e.g., deviations of 10% for Global Warming Potential, 20% for Acidification Potential and Eutrophication Potential, and 40–50% for Renewable Primary Energy.