City of Eden – Rooftops – why not? honourable mentions

Honourable Mentions at the Rooftops – why not? Competition. For further information visit: International ContestA

The Ihme-Center was planned as a commercial and residential center in the city area of Hanover, Germany in the 1960s.
Situated next to the river “Ihme” it contains some of the highest buildings in Hanover. Only a few years after its construction in 1972- 1974 the failure of the concept of a “city in the city” became visible. A lot of concepts to revitalize the complex have been created, but until now none of them have been realized. The last construction work was stopped in January 2009 and left open spaces behind, which have been cored and are now secured with construction fences.


The concept of metamorphosis consists of transforming the Ihme- Center into a paradise for flora and fauna. The complex of buildings turns into a central European landscape refuge. The spacious roof areas of the Ihme-Center play an essential role within the concept: Due to their diverging heights the roofs have the advantage of heterogeneous locations with different climate and ground conditions. These will be increased by constructional arrangements like deploying substratum to achieve the highest biodiversity.

A vital ecosystem with different biotopes will be developed to offer a multitude of animals and plants a new habitat in the city.
The concept consciously plays with contrasts. While the complex of buildings is now dominated by concrete, in future its dull and grey appearance will be overgrown by plants.

The “City of Eden” does not exclude humans. Visitors can experience the paradise and take part in the newly initiated community gardens on the rooftops in the southern part of the complex.


In several buildings of the Ihme-Center, construction machines will rip openings through the attic, which will reach down to the ground floor. Umbrellas will be installed in the middle of these breakthroughs, so that they jut three meters out of the rooftop. The umbrellas conduce to catch rainfall and lead it into a lake at their bottom.

In months of low precipitation water from the lake can be pumped up through hoses, which are located inside the metal rails of each umbrella. The rails are equipped with several sprinklers, which serve the surrounding plants and animals with water. Sunshine and sprinkling create rainbows inside the breakthroughs. Outside the buildings the umbrellas will be installed freestanding in the river. In wintertime they can be closed to protect them from damage.


In the bigger part of the complex the quality of living conditions is so insufficient that the residents of the buildings with the highest vacancy will have to move out.


The deconstruction of the now abandoned buildings will be expanded to the upper levels. Not supporting walls and residual windows and materials will be removed and recycled.


To bring daylight into the floors, break- throughs with a diameter of 10m will be made going through all levels. This allows birds and seeds to gain access to the buildings. Together with the weather conditions they compose the stimulating factors for the metamorphosis of the habitats inside the Ihme-Center.

On the ground of each breakthrough there is a lake which reflects the daylight into the surrounding levels and therefore provides the lower levels with further light.


A new arm of the river “Ihme” will be built through the Ihme-Center in order to create alluvial meadows. Depending on the water level of the river, some areas inside the Ihme- Center will be flooded from time to time.


A walkabout guides through the whole rearranged complex and allows visitors to experience and discover the different biotopes. The path leads via stairs inside the breakthroughs up to the roofs.

From here not only the surrounding city can be viewed, but also the biotopes which cannot be accessed.
The different levels with their diverse habitats for plants and animals can be watched from the stairs.

At first substratum has to be deployed to create a basis for the vegetation. The plants and animals will be chosen according to the habitats. Especially endangered species receive new habitats in the Ihme-Center. The applied biotopes will be left to chance. The initial planting will be carried out as an urban township project. This way the residents of the district can take part in the transformation process of the once eyesore into a paradise.

Group member: Adrian Reinboth
More info:  International ContestA