New Minergie Apartments in Malley Overheat, Sparking Cooling Concerns

New Minergie and SNBS-certified apartments in Malley, Switzerland, built by CFF, are facing unexpected overheating problems, leaving residents struggling with high indoor temperatures. Despite the labels promising ideal living quality with minimal environmental impact, tenants who moved in mid-2025 are experiencing discomfort.

One resident reported that their apartment consistently exceeded 26.5°C, the recommended maximum for Minergie buildings, even before the recent heatwaves. This led them to install air conditioning. A non-representative survey by a new residents' association indicates that nearly 80% of respondents are suffering from the heat.

CFF's own readings show nighttime temperatures reaching 28-29°C during peak heat, even with proper use of sun protection and ventilation. While temperatures are more moderate outside extreme periods, the persistent warmth is a significant concern for inhabitants of these supposedly state-of-the-art buildings.

The recurring issue of overheating in energy-efficient buildings is prompting discussions about the necessity and feasibility of cooling solutions in modern, environmentally conscious housing.

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Before even the official heatwave, from the end of May, my apartment has exceeded 26.5°C daily, the recommended maximum for Minergie constructions.