Cooling the city with green roofs.

Green roofs have gained more attention since recent research demonstrated that adding volcanic ash to roofs can stabilize temperatures, prevent weeds, withstand harsh weather, drain water effectively, and require less maintenance. Germany, Switzerland, and Scandinavia have conducted most of these pioneering studies.

According to the German Green Building Association (BuGG), by the 2020s, Germany had accumulated approximately 3.1 million ^square kilometers of green roofs. In 2015, France became the first country to pass a nationwide law requiring the roofs of new commercial buildings to have greenery or solar panels.

According to the latest market research, the green roof sector in North America has grown by more than 45%, with approximately 1,215 green roof projects. Chicago, the city with more green roofs than any other city in the U.S., installed approximately 56,000 ^m² of green roofs last year and plans to undertake 600 projects to bring the total number of green roofs to approximately 650,000 ^m² .

Research on green roofs in North America began later than in Europe. The environmental consulting firm American Rivers estimates that a $10 billion investment in green roofs could create 190,000 jobs and cover 4.5 billion ^square meters of roof space.

Dr. Chris Lawson, senior designer at CK Architectural, said that despite growing awareness of carbon neutrality and environmental concerns, green roofs still face significant barriers related to investment, cost, and trust. Some areas encourage building owners and developers to install green roofs. For example, the City of Philadelphia offers a tax credit that covers 50% of the cost of a green roof, up to $100,000.

Large eco-resorts are also recognizing the benefits of green roofs. At the NH Collection Copenhagen hotel in Denmark, 3,000 square meters ^of evergreen plants cover most of the roof area. These plants are aesthetically pleasing, changing color from green to yellow and pale pink, while they absorb 50%-70% of rainfall.

Circe Sher, co-founder of Piazza Hospitality, shared that guests at the H2hotel in Healdsburg constantly request to see the vibrant roof adorned with flowers, birds, and bees. 75% of the roof is green, mimicking the surrounding hills.

David Goldberg, Director of Stensgar Pavilion Design at the Coeur d'Alene Casino Resort Hotel in Idaho, USA, stated that the board wanted to showcase the environmental benefits of living roofs, such as heat reduction and cooling, creating a livable environment, and managing stormwater.

As green roofs continue to develop, their potential to transform urban landscapes is becoming increasingly clear. With proven benefits such as enhanced biodiversity, energy efficiency, and stormwater management, the future of green roofs is expected to yield even more advantages.

LAM DIEN