The roof of concert hall and conference building the Doelen is covered with an overwhelming 2,581m² of greenery. That is the size of 10(!) tennis courts. The water storage on the roof has a capacity of 2000 bathtubs (300m³).
It is the first time that a large municipal building and national monument in the heart of the city has been given a multifunctional roof of this size. The roof will be completed during the Rotterdam Rooftop Days on Sunday the 5th of June.
“The new roof on the Doelen will be a green oasis in the centre of Rotterdam. The roof collects rainwater during heavy showers and contributes to cooling when it is hot. The changing climate calls for these kinds of smart solutions. This is not only possible in the underground, but also on roofs," says alderman of the outside space Vincent Karremans.
The new roof has now been given many more functions, although collecting water remains important of course. However, the way in which this collected water is handled has changed: a system with crates has been installed under the plants, in which the rainwater is collected.
The water is stored during rain showers and used during drought to supply the plants on the roof with water. In this way, the city adapts to the changing climate and sustainable water management is ensured.
The rainwater drainage of the Grote Zaal (the largest acoustic concert hall in the Netherlands) has also been adapted, so that the rain from that roof (2.524 m2!) is also collected.
The great variety of plants is a special feature of the new roof. There will be 84 species of native herbs, bulbs, ornamental grasses, plants and shrubs on the roof. There will be five insect hotels and the vegetation will attract bees, butterflies and birds. The green contributes to more biodiversity in the city.
On the Schouwburgplein side, there is a wooden platform of 480 m² on the roof, which will be used in the future for educational, social and cultural activities.
The design for the roof is by Kraaijvanger Architects. The planting plan was drawn up by Deltavormgroep in collaboration with Cruydt Hoeck. Gardening company Van der Tol constructed the roof.
The sustainable roof on the Doelen is one of the projects of Life@Urban Roofs, part of the European LIFE program for environment and climate action. And the roof contributes to the ambitions of the council in the field of sustainability, climate adaptation, the realization of 20 hectares of extra greenery and the restoration of biodiversity in the city.
The municipality of Rotterdam is the owner of this national monument. The roof was constructed in collaboration with the de Doelen concert and conference building, the Schieland and Krimpenerwaard water board, 7 Square Endeavour, the Rotterdams WeerWoord and Rotterdam gaat voor groen.