Turning underused rooftops into climate adaptation assets
Cities across Europe are heating up.
In the summer of 2023, Rome, Athens, and Seville recorded some of the highest temperatures in their histories. Heatwaves are becoming more intense, more frequent — and more deadly. At the same time, extreme rainfall events continue to strain drainage systems, causing urban flash floods with growing regularity.
These are not isolated events. They’re the symptoms of a changing climate acting upon hard, impermeable cities. But amid these surfaces lies a largely overlooked opportunity: rooftops.
The Potential Above Our Heads
Green roofs — also called living roofs — are vegetated layers installed atop buildings. More than a design choice, they offer a form of nature-based infrastructure that cools cities, retains rainwater, improves air quality, and creates biodiversity pockets in dense urban fabrics.
They help cities:
- Mitigate the urban heat island effect
- Reduce stormwater runoff
- Improve insulation and lower energy demand
- Extend roof lifespan
- Create habitat for birds and pollinators
- Contribute to more liveable, healthier environments
The evidence is solid. A study in Berlin showed green roofs can reduce peak summer roof temperatures by over 40°C. In Copenhagen, they’re part of the city’s cloudburst management strategy. In Paris, they’re integrated into plans for urban cooling and food resilience.
Green Infrastructure, Not Green Styling
The European Commission has called for “climate-proof” urban planning in its Green Deal and Climate Adaptation Strategy. Nature-based solutions like green roofs are central to this vision — because they are scalable, multifunctional, and visible.
Some governments are already acting.
Germany has been a leader, with municipal incentives and legal frameworks since the 1980s. France now mandates green or solar roofs on new commercial buildings. Switzerland includes green roofs in its biodiversity protection plans.
But there is still untapped potential in many European cities — particularly in existing building stock. Retrofitting flat roofs, especially in social housing and public facilities, offers a low-disruption, high-impact way to bring nature back into the urban environment.
A New Role for the Roof
For too long, rooftops were seen as passive surfaces — technical spaces to be hidden or ignored. Today, they can become active tools for adaptation, regeneration and public health.
In an era where every square metre of the city must deliver more, green roofs stand out for one reason: they solve multiple problems at once.
Not tomorrow.
Today.