A prospective model of the residential heating equipment stock for decarbonisation scenarios

France has committed to achieving net-zero emissions in the residential sector by 2050, a target that largely depends on replacing fossil-fuel heating systems with low-carbon technologies such as heat pumps, district heating, or green gases. Public policies (including energy performance standards, renovation subsidies, and the phase-out of fossil boilers) are expected to strongly influence household investment decisions. However, their effects on the pace and structure of residential decarbonisation remain difficult to assess with existing aggregated energy models.

This paper develops a prospective model to simulate the evolution of the residential heating-system stock. By explicitly representing equipment ageing, replacement events, and replacement decisions at the dwelling level, the model is designed to assess how public policies shape technology trajectories and energy-carbon outcomes over time. This paper presents the construction and validation of the framework; the simulation of explicit policy instruments is the subject of ongoing work.

The framework relies on an annual simulation in which each dwelling is associated with a main heating system. Equipment lifetimes are modelled using Weibull survival functions calibrated from technical reference quantiles by technology, generating probabilistic end-of-life events. When replacement occurs, technology choice is governed by a three-matrix decomposition combining technical feasibility (dwelling type and existing system), territorial constraints (urban density, local energy availability), and household characteristics (income, tenure status, and energy performance class). The stock is updated year by year, and aggregated indicators (technology shares, final energy consumption, CO₂ emissions) are computed.

Validation focuses on the 2022–2024 period through comparison with observed heating-equipment market shares. The model is then applied to three energy carrier decarbonisation scenarios extending to 2050 to evaluate their implications for residential energy demand and CO₂ emissions.