The scale of the project is quite small, located on a rooftop on a typical Dutch city house built in 1909. Not only small by size, also old in terms of structure. Our ambition was to create a luscious garden space in between the ground and the clouds. In 2005 the roof decking was renewed. A wooden terrace (18 sqm, hardwood FSC), green roof part (approximately 30 sqm), sunroom, indoor stairs, and fence were added.
A mix of perennial plants and dwarf shrubs such as lavender, thyme and origanum was planted according to the recommendations for ZinCo’s green roof system “Lavendelheide”, a hardy plant community suited to rooftop weather conditions as well as living conditions on a soil package of approximately 10 centimeters.
Then began the experiment. Through the years, I’ve added various plants, mostly perennial sorts, to the green roof part, and I was surprised by the marvelous volume created by Lindheimer’s beeblossom, (bloody) cranesbill and a piony, to name a few. The feeling of being immersed in a green world with quite a scenic view of the skyline has made up to the promise of a garden, attracting bees and other insects as well as birds. Notwithstanding its small size, the ecological dynamics I’ve been watching are fascinating, the plant community changing its appearance according to small differences in living conditions such as shadow, sun and rain. I try to implement the esthetics of this plant community to my work as a landscape architect and designer, as I’ve realized a mix of pink, rose-colored, white, violet with yellow and orange can indeed be beautiful!
Rooftop oasis – perennial jungle | Rotterdam Netherlands | Astrid Hölzer
planning, design, implementation | A. & D. Hölzer, landscape architects bnt (tuin- en landschapsarchitect bnt)
structural analysis | Leo Looije
green roof system | Zinco Nederland
roof decking | Archeno/F. Scheen
photographs and text | Astrid Hölzer