From limit values to carbon budgets: Assessing comprehensive building stock decarbonisation strategies

Abstract

Several countries are moving towards imposing mandatory limit values that consider the life-cycle greenhouse gases emissions (GHGE) of new construction projects. While they offer valuable guidance towards low-carbon practices, they may not be sufficient to ensure the building activities alignment with ambitious climate goals. To do so, it is imperative to integrate all stock-level activities dynamics and consider the evolving nature of limit values influenced by the decarbonisation efforts in the energy and industry sectors.This article introduces a methodological framework designed to explore the potential evolution of the dwelling stock GHGE, with the ultimate goal of assessing their alignment with climate objectives. By using a national building stock database, alongside drivers of stock-level activities and scenarios for the decarbonisation of upstream sectors, it facilitates the creation of multiple scenarios and the calculation of yearly and cumulative Whole-Life Carbon (WLC) emissions.France is taken as a case study to investigate the compatibility of its recent implementation of climate and sectoral policies. The findings suggest that prioritising the elimination of fossil fuel usage emerges as an optimal strategy for decreasing operational GHGE. Regarding embodied GHGE, the more ambitious the scenario, the greater its relative contribution, potentially accounting for up to half of the WLC emissions by 2050. In addition to the ambitious transformation of energy-inefficient dwellings, the deep decarbonisation of energy carriers and construction materials plays a pivotal role in the overall decarbonisation of the dwelling stock, while sufficiency measures significantly impact embodied GHGE.