Primary data priorities for the life cycle inventory of construction products: focus on foreground processes

Abstract

Purpose Life cycle assessment can support decisions for improving the environmental performance of construction products. However, the amount of data required for developing life cycle inventories limits the adoption of LCA. This work associates the interpretation of the impact results of construction products at the unit process level with a quantitative definition for the foreground and background system, for guiding primary data collection towards foreground processes that can be affected by decision-makers in the construction sector.Methods A set of construction products commonly used in Brazil is selected and their cradle-to-gate life cycle inventories are modeled using the ecoinvent database (version 2). Life cycle impact assessment is performed using the ReCiPe Midpoint Hierarchist method. The contribution of each process during the life cycle of construction products for each impact category is quantified. These processes are associated with economic sectors, which are classified as belonging to the foreground or background system from the perspective of the construction industry. Foreground sectors are those controlled or influenced by the construction sector and are defined based on the production share consumed by the construction value chain. The elementary flows defining each impact category are also identified. Results and discussionForeground processes show significant contributions to most impact results of construction products. Global warming, fine particulate matter formation, ozone formation, acidification, human carcinogenic toxicity, and terrestrial ecotoxicity are mainly caused by direct emissions and fossil fuel combustion in manufacturing processes. Land occupation for production activities contributes to land 2 use change, while the consumption of fuels, raw materials and water causes fossil and mineral resource scarcity and water consumption respectively. Freshwater and marine ecotoxicities and human noncarcinogenic toxicity have foreground contributions only for steel and copper products due to emissions from the landfilling of mining tails. Ionizing radiation and stratospheric ozone depletion are mostly driven by background processes. A reduced group of elementary flows covers a big share of the environmental impacts of most construction products. ConclusionsThe results indicate priorities for life cycle inventory primary data collection of construction products, by focusing on foreground processes and the corresponding elementary flows that cause many of the potential embodied impacts of construction. Increasing the availability of primary data for these processes improves the reliability of LCA-based decisions in the construction sector, especially in countries which still lack local LCI databases.

Hydrogen production, storage, utilisation and environmental impacts: a review

“…This also explains the fact that many studies did not include all the processes ranging from raw material acquisition to end-of-life management (summarised in Table 3). The two different kinds of data to be collected for an LCA study are: (1) foreground data for foreground systems which includes primary data that can be easily modified or improved and (2) background data for background systems typically comes from Life Cycle Inventory databases (Silva et al 2020).…”

Fluxo de materiais e eficiência no uso de recursos na indústria da construção.

“…A habitação é constituída por uma sala, uma cozinha, um quarto de banho, e três quartos, perfazendo uma área total de 66m 2 . A quantidade de materiais foi obtida em (SILVA et al, 2020 Por fim, importa referir que a participação de mercado, consumo de insumos minerais e energéticos tem alguma incerteza associada, sobretudo nos setores com mercado informal como areia, cerâmica e cal. De todo o modo tentou-se contornar estes problemas através de uma pesquisa bibliográfica abrangente e métodos de cálculo que permitissem uma estimativa próxima da realidade.…”

Proposal of life cycle-based environmental performance indicators for decision-making in construction.

“…Another recommendation for effective indicators is prioritising issues that construction stakeholders can measure, manage, and improve. Therefore, indicators determined mainly by foreground processes (from the perspective of the construction sector) should be prioritized (SILVA et al, 2020). Considering the eight uncorrelated environmental issues associated with the construction life cycle, the ones predominantly caused by foreground processes include: a) Global warming: the production of construction materials is intensive in fossil fuels, and fossil fuels are consumed during building operation (e.g., for electricity production, hot water supply, and heating).…”

“…For instance, calculating the global warming potential requires not only a robust characterization model (in this case, provided by the IPCC) but also collecting data for all greenhouse gases. CO2 represents more than 80% of the global warming potential of most construction products (LASVAUX et al, 2014;SILVA et al, 2020) and is relatively easy to calculate using emission factors (GÓMEZ et al, 2006;WALDRON et al, 2006). In contrast, other greenhouse gases are more challenging to estimate.…”

“…Detailed information is available in the Electronic Supplementary Material. Source: the author, based on the Electronic Supplementary Material ofSILVA et al (2020).…”