in the middle
Status: 10.11.2022 1:00 p.m
Green instead of grey: the bunker in Hamburg is getting a huge roof garden. 4700 plants and trees should ensure a better climate in the city. What grows at a height of 60 meters and why is there criticism?
It is supposed to be Germany’s most spectacular roof garden: the high-rise bunker on Feldstrasse in Hamburg. Since this week, a huge park with green and common areas has been created above the roofs of the Hanseatic city. In addition, 1700 square meters of the facade and a 300 meter long “mountain path” will be greened.
For this purpose, the high bunker was increased by five pyramid-like floors to 58 meters: the gray bunker in St. Pauli becomes a green bunker. In the future, up to 900 people will be able to enjoy the view of the Michel, the Elbphilharmonie and the harbour.
The visualization shows what the green bunker should look like.
Image: picture alliance / Bunker Planning Office/Visualization\ Bunker Planning Office/dpa | planning office Bunker
“An English garden would not suit St. Pauli”
Construction on the project started in mid-2019, but the greening was repeatedly delayed due to Corona and delivery bottlenecks. Now the traditional Hamburg tree nursery Lorenz von Ehren started with the planting work – mountain pines and columnar juniper were transported to the bunker by crane and planted.
These are plant species that are primarily native to northern European and Alpine regions and can withstand frost, heat and storms. “An English garden would not suit St. Pauli. So it will look natural and unspoilt here on the bunker roof, a little wild, a little disheveled,” says Frank Schulze, spokesman for the project. Thanks to the specially produced substrate, the plants should always stay green and feel at home even at a height of 60 metres.
Fight against the urban heat islands
The bunker is to become a showcase project for green architecture and climate change adaptation. Cities are particularly affected by global warming due to heavy rain, heat waves and air pollution. At the same time, there are fewer and fewer green spaces due to the housing shortage, so metropolises are increasingly becoming urban heat islands. “We need more vegetation in the cities,” says climate expert Marco Schmidt from the Institute for Architecture at the Technical University of Berlin.
Because plants on the roof and facade store moisture and can thus bind water and return it to evaporation. Their evaporation capacity ensures cooling in summer and at the same time relieves the drains, which are overwhelmed by heavy rain. Over the next five years, the scientist will use sensors in the bunker to collect important data on heat storage, evaporation processes and biodiversity. So he analyzes how plants can improve the climate in the city.
Landscape architect Felix Holzapfel-Herziger shows an illustration of the converted bunker.
Image: dpa
First anti-aircraft, then media location
A memorial and information center for the victims of the Nazi regime and the Second World War will also be set up to commemorate the history of the building. Because the bunker was built in 1942 by forced laborers. During the Second World War, the Luftwaffe used it for its anti-aircraft guns, and up to 25,000 people found shelter in the building during bombing raids.
After the war, the bunker changed again, becoming a “media bunker” for musicians, photographers and media workers. NDR, then NDWDR, broadcast the first in 1952 daily News out of the bunker.
Opening planned for 2023
Now the bunker should get a new function. The idea for this came from a local residents’ initiative in 2014. Her suggestion: a roof garden that is freely accessible to everyone. This plan is now being implemented by client Thomas Matzen and his company Matzen Immobilien KG. He also bears the costs for the conversion: instead of the planned 30 million euros, they now amount to 60 million euros. The company will also cover the cost of tending the plants once the roof garden is complete.
In addition, rooms for exhibition areas, urban gardening opportunities, accommodation for scholarship holders and artists, a hall for school sports and cultural events as well as catering facilities and a hotel will be created in the bunker.
Critics complain about the commercialization of such a historic place and fear that the warning monument character of the bunker would be lost. The supporters, on the other hand, hope that the roof garden and the additional offers will get more people to deal with the history of the bunker. The “Green Bunker” is scheduled to open in early 2023.