No abstract

The climate crisis is urging us to act fast. Buildings are a key leverage point in reducing greenhouse gas (GHG) emissions, but the embodied emissions related to their construction often remain the hidden challenge of any ambitious policy. Therefore, in this paper, we explored material GHG neutralization where herbaceous biobased insulation materials with negative net-global warming potentials (GWPs) were used to compensate for building elements that necessarily release GHGs. Different material diets, as well as different building typologies, were modeled to assess the consequences in terms of biobased insulation requirements to reach climate neutrality. Our results show that climate-neutral construction can be built with sufficient energy performance to fulfill current standards and with building component thicknesses within a range of 1.05–0.58 m when timber- and bamboo-based construction is chosen. Concrete-based ones require insulation sizes that are too large and heavy to be supported by the dimensioned structures or accepted by urban regulations. Moreover, a time horizon of 20 years is more appropriate for assessing the contribution of material shifts to biobased materials in the transition period before 2050. This paper demonstrates that this is technically feasible and that climate neutrality in the construction sector just depends on the future that we choose.

No abstract

In the building sector, the new standards for energy efficiency are reducing the energy consumption and the carbon emissions for building operation to nearly zero. As a result, the greenhouse gases emissions and related environmental impacts from materials production, and especially insulation, are becoming dominant. In the next future, most of building stock is expected to be refurbished and a great amount of construction materials will be consequently required. A relevant share of waste is generated from building construction and demolition and limiting the volume is a priority of the EU community. In this work the renovation of industrial buildings in a dismissed area located in Lecco, Italy, was considered as case study. Five alternative construction systems for renovating the building envelopes were assumed, and a life cycle assessment (LCA) adopted in order to measure the environmental impact of each alternative. The results where compared with a scenario which includes demolition and reconstruction of a similar building with the same net volume and thermal resistance. The results showed that timber and concrete are the most valuable materials to rebuild the structures in case of demolition, contrarily to steel which leads generally to higher environmental impacts, except land use. Refurbishment scenarios generally account for a lower global warming potential (GWP) even if demolition, waste treatment and benefit from recycling/reuse are taken into account.

This work brings together some recent research and results activities aiming at investigating the environmental benefits of using bio-based materials for the construction and refurbishment of residential buildings. The positive environmental effects of wood and other biogenic materials replacing other, more important, conventional ones, analysed through the application of Life Cycle Assessment methods, are here reported. Moreover, the investigated strategies for Carbon Capture and Storage (CCS) are here discussed, to evaluate the potential of carbon uptake of fast-growing biogenic materials when used as insulation systems. The results show the effectiveness of bio-based materials in contributing to the mitigation strategies of the impacts due to climate change.