'Together we make the Netherlands greener'

In matters such as water storage and sewerage, green roofs are playing an increasing role. "Our field is becoming more and more multidisciplinary; more and more we are integrally involved in sustainable building designs," says commercial director Aart Veerman of Van der Tol - nationwide specialist in design, engineering and installation of roof gardens and vegetation roofs. "All our work at Van der Tol is done from our vision of the importance of green and sustainability for the city."

ECOcity is what Van der Tol calls it. Van der Tol's climate-proof ECOcity is greener, healthier and more livable, according to Veerman. "With the help of green solutions, biodiversity is promoted, rainwater is used effectively, warming of the city is prevented and the indoor climate is improved." Working together on the ECOcity of the future, Van der Tol does so with NLgreenlabel, Living on Roofs, The Healthy City, Amsterdam Rainproof, The Butterfly Foundation and Rooftop Revolution. "Our green solutions are offered constructively from an integral approach and can be found in a mini ECOcity in our Berkel en Rodenrijs location. A location that is continuously being developed with sustainable innovations." 

The roof gardens and vegetation roof segment has developed with the rise of sustainable building. Veerman: "In sustainable multiple use of space, a green roof can play a big role. We call it eco-engineering. We represent a product that is ideally suited for chain cooperation. Co-makership? We don't do anything else anymore." Starting around 1995, you saw the structural emergence of the roof garden and vegetation roof in building designs. "As a specialist, from the very beginning we both tried to answer a market demand and did pioneering work. We have the people in house to supervise both design, engineering and implementation, and we employ our own landscape architects. But we can't do it alone."

Living On Roofs

A green roof does not stop at roofing, "an industry we work closely with in product development," Veerman continued. "The key is to work together integrally with other stakeholders in construction to achieve intelligent buildings that contribute to the built environment." The Leven Op Daken knowledge platform takes integral collaboration to the next level. "Affiliated landscapers, roofers, installers, suppliers and manufacturers form collaborative teams within Leven Op Daken, which can provide guidance from advice to maintenance and management. We also step out together; ideally we would like to see greenery that disappears on construction sites replaced 1-to-1."

Integral solutions combined with green roofs can contribute substantially to the increasing peak load in stormwater runoff, argues Veerman. "From that starting point, government investments in water storage/sewerage can be approached differently in the future. For example, a sewer system is depreciated over 60 years. That means you have time to come up with new solutions together, such as gray water circuits or the complete disconnection of buildings from the sewer system." These then provide their own drainage, such as the completed Depot Boijmans van Beuningen in Rotterdam. "The technology is already there; so is the cooperation in the industry. Together, we are making the Netherlands greener."