The ability of homeowning households to finance renovation investments is an often overlooked barrier towards achieving the long-term energy and climate goals. Especially a quantitative assessment of this financial barrier has been missing in the literature. A methodology to perform such an assessment is developed and applied to the Flemish region in Belgium, which can be seen as a proxy for similar regions elsewhere in Europe. Two empirical datasets are combined through a process of stochastic sampling, to estimate both the renovation costs (towards a 2050-proof level of energy performance) as well as financing capacities for a representative sample of households. The analysis shows that approximately half of the homeowning households cannot finance the necessary renovations. This finding holds regardless of whether renovations are financed and executed all at once, or spread over multiple years into the future. When the additional investment costs associated with comfort increasing measures that typically coincide with energy renovations are included, the share of households facing a shortage in financing capacity increases by 7 to 9 percentage points. The fact that half of all households can finance comprehensive renovations and yet decides not to do so indicates that new policies are required to activate them in the coming decade.