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Coach of the project :

David Volk, EBF

How and Where?

The rooftop greenhouse is located in the centre of Oberhausen directly on the Altmarkt. 

This research greenhouse has been built on top of the five-storied administrative building in Oberhausen. It is accessible to the public from the greened steel scaffolding (the vertical garden) that connects the rooftop greenhouse with the Altmarkt square on ground level.   


Production: 1260 m², 1100m² production, 160m² research to cultivate herbs, salads and strawberries. 


The objectives of the greenhouse are partly production, partly research. 

The stairway to the rooftop greenhouse appears as a vertical garden. A spatial scaffolding serves as a supporting structure for stairs, platforms, freight lift, plant and filter troughs as well as climbing aids. In this way, a varied course is created that offers visitors a variety of places and views and invites them to participate in "urban gardening".  


The rooftop greenhouse was conceived as an experimental field in the field of food production in cities. It’s now a research greenhouse and participatory "urban gardening" project for schools etc. 

The rooftop greenhouse Altmarktgarten is open to interested visitors or e.g. school classes as part of guided tours. The ebb and flow tables can be rented by residents or restaurants; for example, a restaurant operator on the market square grows his herbs directly on the roof of the job centre.  

The very central location of the production facility in the city centre eliminates long supply chains, so the ecological footprint of the products is also minimised. 


Project leader and organization: Friedhelm HAAS, Head of the company. 

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