The south of France has the lowest number of poorly-insulated houses, a new study has shown.
Only 4.2% of homes were classed as F or G in terms of energy efficiency in Perpignan (Pyrénées-Orientales), and 6.6% in Nîmes (Gard).
The French diagnostic de performance énergétique indicates how energy-efficient a property is from A to G, with better ratings sometimes fetching higher sale prices.
Good insulation also means that a house will be warmer in winter and cooler in summer.
Nice and Montpellier also ranked highly in the study – both with 7.2% of poorly-insulated properties – and Toulouse and Aix-en-Provence came in just behind with 7.3%.
The study, which was carried out by energy consumer advice platform Hello Watt based on data from the Agence de l’environnement et la maîtrise de l’énergie, also showed that Ile-de-France is the region with the highest number of poorly-insulated houses.
Hello Watt stated that the better insulation of houses in southern France is down to the building materials, “which varies according to the region.
“In Provence, for example, many houses are made from stone, which allows them to store the heat during the day and diffuse it progressively through the house while the temperature falls.
“In addition, the low proportion of older houses can also explain the good results.”
On a departmental level, Gironde was the best place for effective insulation, with 94.6% of properties having it.
In Ile-de-France, the high number of homes built before 1970 means that fewer buildings have good insulation. In addition, property prices in the capital often dissuade people from investing in homes with good insulation, which can be more expensive.
In Paris, 24% of homes are poorly insulated, with 22.3% of properties in Saint-Denis and 21.8% in Argenteuil.
‘Richer’ areas do not necessarily contain homes with better insulation; the study showed that 58% of poorly-insulated properties were home to middle or high-income households.
Alpine departments also performed poorly in the study: 30.2% of properties in Hautes-Alpes had low energy ratings, while it was 28% in Savoie and 26% in Haute-Savoie.
In these places, this was due to the “cold and harsh climate, which requires significant heating systems and increases consumption per m2.”
Since the adoption of the 2021 Loi Climat, landlords will from 2023 be banned from renting out the 90,000 homes which consume more than 450kWh per m2 per year.
This ban will extend to properties with a ‘G’ energy rating from 2025, those with an ‘F’ rating from 2028, and those with an ‘E’ rating from 2034.
There are currently around 1.7 million rented properties with G and F ratings in France.