Black, overheated rooftops still dominate many cities, but they also offer a unique chance for change. Green roofs – covered with native plants and flowers – provide cooling during heatwaves, capture rainwater, and enhance biodiversity. In the Netherlands alone, there are 460 km² of flat rooftops, an area the size of 67,650 football fields.
VU researcher Katinka Quintelier (School of Business and Economics) explores how this unused space can be transformed into a resource for nature, energy, and urban livability.
Green roofs: more than plants
A green roof offers multiple benefits at once: temperature cooling in summer, insulation in winter, water storage during heavy rainfall, and a habitat for insects and plants. When combined with solar panels, energy yields can even increase by up to 16%, thanks to the cooler rooftop surface. Green roofs also extend the lifespan of rooftops and provide residents with the wellbeing of overlooking greenery.
Challenges in practice
Still, there are obstacles. Costs and ownership are the biggest barriers. Quintelier explains: “Many people like the idea of green roofs, but the question is always: who will pay for it? That’s why we are exploring new ownership and service models, so that costs and benefits can be shared more fairly.”
The city of the future
According to Quintelier, green roofs can make a real difference, both on small and large scales. They contribute to cooler, healthier, and greener cities and buildings. “If we do nothing, heatwaves will cause more deaths and the economic and ecological costs will rise. Green roofs give us the chance to tackle multiple problems with a single measure.”