Alternative pathway for a nearly zero emission building stock in 2050

This paper presents a comprehensive bottom-up approach to identify the final energy demand and GHG (Greenhouse Gas) emissions of the residential sector by 2050. The approach integrates the technical constraints of retrofitting existing residential buildings and the rebound effect, which are often overlooked in energy demand studies.

A detailed analysis of the current energy consumption patterns in the French residential sector is conducted through dynamic building simulation, followed by an assessment of the potential for energy savings through various retrofit measures. These measures are evaluated considering their technical feasibility and cost-effectiveness. The rebound effect, which refers to the increase in energy consumption resulting from improved energy efficiency, is also incorporated into the model. This is crucial as it can significantly affects the net energy savings achieved through retrofit measures. Historical figures are used to accurately assess the limitations of the HVAC systems replacement market and building stock destruction.

Then, each building typology and location are simulated, with retrofitting actions included, in a bottom-up approach from 2025 up to 2050, allowing a more realistic and comprehensive understanding of the residential sector’s energy demand and GHG by integrating detailed building constraints.

The results show that nearly zero emission can be achieved with a balanced-mix. By 2050, natural gas is replaced by bio-methane. The usage of bio-methane representing 20% share of the building stock energy consumption.