France study finds nine in ten homes unfit for heatwaves

A joint study by the housing union Ignes, the Alliance of Electrical and Digital Building Solutions, and consulting firm Pouget Consultants analyzed around 9 million summer‑comfort indicators from the energy‑performance diagnostic (DPE) collected since 2021. It concluded that roughly 90 % of French dwellings are not equipped to cope with extreme heat, including many recent or highly rated energy‑efficient homes. About half of all residences can be classified as “thermal boilers” that retain heat and lack sufficient external shading such as shutters or blinds. The report highlighted several cities – Lille, Paris, Bordeaux, Reims and Perpignan – where the proportion of such homes is especially high. The authors called for coordinated action to improve building design and retrofit measures, noting that current DPE metrics do not fully capture summer‑comfort performance.