Make your flat roof contribute to the health of your city. Netherlands-based Dakdokters (Roof Doctors) make this possible by transforming your roof into a breathe of fresh air. Founded in 2010, the Dakdokters aim to increase the biodiversity in cities by making the city roofs healthy and more livable for plant, animals and people. They got their initial idea while thinking of the long lists of endangered plants as well as the troubled decrease in the bee population, a very essential chain in our ecosystem. Their plant of choice is sedum, a family of flowering plants, members of which are commonly known as stonecrops. The beauty of the Roof Doctors’ solution is the multitude of advantages a green roof brings the city and her environment.
The green roof has many advantages
The modern city has a big challenge in processing the rainwater as the rain showers are getting more concentrated and heavier while the amount of green in the city remains the same. This puts a lot of pressure on the current sewage system, which would require a huge investment to extend. The Roof Doctors have invented a system they call the Polderdak. The Polderdak consists of a small dike construction on the existing roof. The height of the dike is determined by the desired water storage capacity on the one hand, and the carrying capacity of the roof on the other. The dike is provided with valves, which controls the water level and the level of outflow. Control of the valves can be linked to various parameters such as the water level on the roof or the expected rainfall in the next 24 hours.
Green roofs have cooling qualities. In the summer, the original black bitumen roof can reach up to 85 degrees Celsius compared a maximum temperature of a green roof of 35 degrees Celsius. Moreover, the inside temperature is lowered by up to 4 degrees as well. This has a direct benefit on your energy bill during hot summers.
Green roofs extend the lifetime of the bitumen, increases the performance of solar panels (output increase of 6%), absorb heavy metals, reduce noise and above all make the city breathe again.