Heat waves are intensifying and lasting longer. Across Western Europe, hot periods are projected to extend from June to October by 2040–2050, with nights remaining warm for several consecutive days.
Cost indicators: (€) low · (€€) moderate · (€€€) significant investment
Core strategy: Rather than cooling your entire home, focus on one cool room per person. It is the most efficient and cost-effective approach.
Short term — act now
Houses and flats
- Close shutters, blinds, and curtains before 9 am on south-, west- and east-facing windows
- Ventilate at night as soon as outdoor temperature drops below indoor temperature — fit a insect screen / mosquito net (€) so you can keep windows open without letting insects in
- Use a fan as an extractor: placed facing an open window, it pushes hot air out
- Solar window films (€) — reduce solar heat gain by 30 to 70 %
Houses with outdoor space
- Shade cloth stretched over an exposed terrace (€)
- Water plants in the evening — evapotranspiration cools the surrounding air
Medium term — plan over coming weeks
- High solar-reflectance curtains or blinds (€)
- External shutters or louvres, if not already installed (€€)
- Portable air conditioner for one room (€€) — no installation needed; pair with good window shading
- Awning or bioclimatic pergola for a balcony or terrace (€€)
Long term — planned works
- Fixed reversible heat pump — air-to-air (€€€) — heats in winter, cools in summer; install in 1 or 2 key rooms
- Flats: check co-ownership rules regarding the outdoor unit
- Roof / loft insulation (€€–€€€) — top priority for houses; poor roof insulation can add 5–8 °C inside
- External wall insulation (€€€) — reduces facade overheating throughout the day
- Green roof or living walls (€€€) — can lower temperature under the roof by 2–4 °C and improve thermal inertia
A well-insulated home uses two to three times less energy to achieve the same comfort level. Insulation is the foundation of any climate adaptation strategy.