Europe: ‘Urban Farming’: Are rooftop fields the future?
Up to two million square meters of roof space could be used for plant cultivation in Berlin alone. But the investment costs are still relatively high.
By Florence Schulz
EURACTIV.de
Sept 30, 2020
Excerpt:
In Europe, urban farming is still in its infancy.
“Every morning, I ask myself why not many more cities invest in it,” says Jörg Finkbeiner, architect and co-founder of the Berlin network ‘Dachfarm.’ The consortium consists of gardeners, agroscientists and architects, who together plan greenhouses for growing crops in the city.
However, Finkbeiner believes that this cannot be the case with urban farming, because most buildings are not statically suitable for it: “If you put crops in tubs on a roof and water them, you can quickly achieve 300 kilograms per square meter. Most buildings can’t support that.”
Dachfarm, therefore, relies on roof structures that are as light as possible and are built on top of existing buildings. The plants grow either in substrates such as pumice, lava or compost, as these are much lighter than soil, or in hydroponic systems, where the nutrient supply is provided directly via a nutrient solution.
The glass gardens are designed to operate as efficiently as possible by using the waste heat from the building, collecting rainwater or recycling greywater from households.
