38 Spotlight Photo: Too van Velzen Green roofs in Zuidas: enthusiasm and obstacles ‘There are tens of thousands of square meters grey gravel roofs in the area just waiting to be turned green.’ In 2017 Green Business Club Zuidas and the Zuidas Amsterdam Development Office declared the ambition to have realised 25 000 m2 of Parkdak in 2020. A Parkdak is a green roof with high-quality growth that can also act as a water buffer. Existing roofs The advantages of a Parkdak are obvious: it insulates, avoids water-flow problems and offers a green outside area. The Zuidas building envelope guidelines stipulate that roofs up to 50 meters high must include high-quality plant growth. With new property developments in the last years the amount of green square meters has increased impressively. For the instigators however, this is not enough and they want to see existing roofs turn green too, mainly because existing buildings in particular can use the extra energy saving and water buffering advantages. Roof scans Rooftop Revolution was tasked to make an inventory of the existing roofs, offer roof scans to owners and 31.158m2 green / blue roof in Zuidas (183,286 m2 total roof area), of which: companies and to put interested parties in contact with companies that can lay these types of green roofs. From the end of 2017 until the end of 2018 they made an inventory of 74 office buildings and 25 apartment buildings with a total surface area of 180 000 m2. Detailed advice was given on four properties with a combined surface area of almost 17 000 m2 to turn their roofs into green areas. Rooftop Revolutions director, Jan Henk Tigelaar, was involved in the Zuidas rooftops in 2018 and encountered lots of enthusiasm but also some obstacles. ‘One of the problems that we came across is ownership and the distance between the owners and their real estate. Many properties in Zuidas are 53 % green 11 % recreational use owned by international investment companies that hire a management firm to look after their real estate. It is the owners and not the leaseholders that decide whether to invest in a green roof. It turned out to be difficult to convey the local enthusiasm for green roofs to the owners. We performed a detailed analysis on a number of large properties and showed what could be achieved on the roofs. The roof scans can be decisive in putting a Parkdak in an agenda. We now also have a good overview of what the rooftop landscape looks like in Zuidas. There are tens of thousands of square meters grey gravel roofs in the area just waiting to be turned green! The urgency to start acting on this will hopefully get through to the owners quickly.’ 11 % solar panels 25 % water retaining
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