Bio-based insulation materials: an opportunity for the renovation of European residential building stock – Evaluation of Carbon uptake benefits through a dynamic life cycle assessment (DLCA)

Abstract

European Union, as party to the Paris Agreement, shall contribute to hold the increase in the global average temperature to well below 2°C, that, according to the Fifth Assessment Report of IPCC, implies the Carbon budget shall not be exceeded. Building sector in Europe is responsible for 36% of the GHG emis- sions, and its renovation represents a priority. A common tendency dealing with energy e ciency is to focus only on operational energy, neglecting the impacts coming from materials production, on site construction, and disposal. Actually, such environmental burdens may result to be cumbersome, especially if a short- term perspective is considered. The task of the present work is to investigate and holistically assess the bene ts deriving from the use of bio-based, renewable materials for the energy retro t of the European residential building stock. Ap- plying a dynamic LCA, that allow the consideration of a dynamic time horizon and a consistent accounting of the biogenic CO2, the work aims to show how much the choice of the insulation material can a ect the overall Carbon balance. A simulation of 200 years starting from 2018 at the current renovation rate is performed. Five di erent external walls alternatives for the building retro t, including fast-growing bio-based, wood, mineral and polystyrene solutions, for three di erent end of life scenarios, are investigated. Results show that, beside to the primary goal of increasing passive performances, a large-scale use of bio- based building insulation materials can lead to a climate mitigation e ect, as the biomass regrowth induce a bene cial Carbon sink e ect since the rst years. Furthermore, renovation rate has proved to be by far the most important para- meter to control; for achieving its rise, modular pre-assembled facades should be encouraged. Addressing rapidly the transition toward a zero-carbon society is the priority. In this perspective, bio-based materials represent an opportunity that should not be wasted.