LCA-based study on structural retrofit options for masonry buildings

Abstract

Purpose: Over the last decade, the rehabilitation/renovation of existing buildings has increasingly attracted the attention of scientific community. Many studies focus intensely on the mechanical and energy performance of retrofitted/renovated existing structures, while few works address the environmental impact of such operations. In the present study, the environmental impact of typical retrofit operations, referred to masonry structures, is assessed. In particular, four different structural options are investigated: local replacement of damaged masonry, mortar injection, steel chain installation, and grid-reinforced mortar application. Each different option is analyzed with reference to proper normalized quantities. Thus, the results of this analysis can be used to compute the environmental impact of real large-scale retrofit operations, once the amount/extension of them is defined in the design stage. The final purpose is to give to designers the opportunity to monitor the environmental impact of different retrofit strategies and, once structural requirements are satisfied, identify for each real case the most suitable retrofit option. Methods: The environmental impact of the structural retrofit options is assessed by means of a life-cycle assessment (LCA) approach. A cradle to grave system boundary is considered for each retrofit process. The results of the environmental analysis are presented according to the data format of the Environmental Product Declaration (EPD) standard. Indeed, the environmental outcomes are expressed through six impact categories: global warming, ozone depletion, eutrophication, acidification, photochemical oxidation, and nonrenewable energy. Results and discussion: For each retrofit option, the interpretation analysis is conducted in order to define which element, material, or process mainly influenced the LCA results. In addition, the results revealed that the recycling of waste materials provides environmental benefits in all the categories of the LCA outcomes. It is also pointed out that a comparison between the four investigated options would be meaningful only once the exact amount of each operation is defined for a specific retrofit case. Conclusions: This paper provides a systematic approach and environmental data to drive the selection and identification of structural retrofit options for existing buildings, in terms of sustainability performance. The final aim of this work is also to provide researchers and practitioners, with a better understanding of the sustainability aspects of retrofit operations. In fact, the environmental impacts of the retrofit options here investigated can be used for future research/practical activities, to monitor and control the environmental impact of structural retrofit operations of existing masonry buildings

An Integrated Method to Evaluate Sustainability for Vulnerable Buildings Addressing Life Cycle Embodied Impacts and Resource Use

“…At this point, real-world applications of retrofitting can be investigated to assess their environmental impacts [38]. Some studies [47,[51][52][53][54][55][56][57][58] focused on structural retrofitting of the existing building and their environmental impacts. Some [29,59] combine structural and sustainability metrics with economic terms implemented by monetizing CO 2 emissions.…”

Embodied carbon mitigation and reduction in the built environment – What does the evidence say?

“…57,118], in light of cradle-to-cradle design and circular economy approaches which have recently received increased attention as a valid and viable alternative to the traditional linear make-use-dispose paradigm. Intini and Kuehtz [55] investigated the use of recycled plastic bottles to manufacture thermal insulation in Italy and concluded that recycled polyethylene terephthalate (PET) can reduce environmental impact as much as 46% with respect to GWP.…”

Indicators for quantifying environmental building performance: A systematic literature review

“…Moreover, San-José Lombera & Aprea [52] emphasise that the sustainability of industrial buildings should not only be structured around energy consumption, but also include land, water, and material usage. The reuse potential is not covered substantially, but there is for example research showing that the recycling of building materials in masonry buildings generates environmental benefits due to avoided impact of virgin material production [55]. Related to reuse potential, Munarim et al [47] compare building rehabilitation with new building construction and disclose that the construction of a new office building would require about 250 years more to amortise total energy impacts when compared with the rehabilitation and transformation of an old hotel building to an office building.…”