'Good Urban Practice' brings more green to cities

Hertogensite/Janseniushof: greenery up to the roof of the underground parking lots

The Hertogensite, the former hospital site in the heart of Leuven, is being transformed into a new city quarter. Whereas in the past this historic site mainly housed care, the new interpretation focuses on 'unburdening' the future inhabitants. Here people will live in green surroundings along the Dijle, which will once again flow above ground, amid historic buildings and numerous commercial facilities. A place where housing, nature and culture merge into a whole that honors the past and embraces the future. And for the "green roofs," Disaghor-Dockx guarantees!

Those who love nature had best come to live in the center of Leuven these days. Because the formerly petrified hospital site is being redeveloped into an inner-city green lung in which water and nature play the leading role. In addition to the abundance of greenery, the 'Aa' and 'Dijle' watercourses are also being given oxygen again. The latter crosses the area from north to south, forming a structuring and image-defining element of the Hertogen site. The entire site is strongly anchored within the surrounding urban fabric, by numerous green passages, boulevards, squares and bicycle and walking paths. The 1.6-hectare central city park, with its sunbathing lawn sloping towards the banks of the Dijle, forms a central resting point. The tree species chosen guarantee ecological diversity and the flowery hay meadows add an aesthetic touch.

Lots of greenery, including on rooftops

But the greenery in this case was also extended to the roofs of most of the buildings. An expert in the field is Disaghor-Dockx. The company is one of the main suppliers for (garden) contractors and public authorities in Belgium. Through a strong network of depots and technical support 'on the field', they are an important trading partner for all companies and authorities active in 'green space'. Indeed, the Ruiselede-based company, currently managed by Sébastien de Cartier d'Yves and Celine Van Rijckeghem, takes the greening of urban environments very seriously, partly through their 'Good Urban Practice' project. 

Intelligent long-term vision

Sébastien de Cartier d'Yves, Managing Director of Disaghor-Dockx: "Gradually, the livability of our urban environments in Flanders, Brussels and Wallonia is reaching its limits. Our 'space' has become a scarce commodity. Flanders is one of the busiest regions in Europe. The steady growth of the population and annexed villages and cities put unprecedented pressure on the living environment and nature. Resolutely opting to integrate 'green' within spatial planning demonstrates an intelligent long-term vision. Through 'Good Urban Practice' we want to inform the various actors about the latest possibilities to achieve together a sustainable, social, economic and ecological integration of 'green' in public space.

Green roof construction the only solution

Sébastien de Cartier d'Yves, business manager of Disaghor-Dockx: "For De Hertogensite and Het Janseniushof, a lot of green areas were provided. This greenery was even extended to the roof of the underground parking spaces. And because we had to start from a concrete floor plate, a green roof structure was the only solution. For this we worked with substrate on the drainage system, 50 cm at Herrgensite and 40 cm at Janseniushof. In the places where the trees are, we then raised the substrate. In addition, to prevent the trees from blowing over, we placed a concrete net on top of the drainage material. The root ball anchors were then attached to this.'

'Where the parking lots are, sub-base lava 0/32 was used as a sub-foundation plus a laying bed. On this laying bed-substrate we then placed the grass slabs. The pathways were then worked out again in mixed rubble with stabilization on top, and the clay clinkers were placed on top of this. In addition, on the Hertogens site, phase 3B, almost everything is permeable to water, think cobblestones with grass joints, cobblestones with gravel, grass tiles and Nidagravel with gravel. This project was carried out by Q-landscape bv from Zoutleeuw, in collaboration with general contractor Algemene Bouwonderneming Vandebos nv from Alken.'