Globally, rising urban populations are increasing the number of people, and the amount of infrastructure, exposed to climate change-related extreme weather events. At the same time, the growth of cities has contributed towards climate change through increased emissions.
HafenCity, a resilient European city on the waterfront
One city that is exploring urban solutions that protect both people and infrastructure from climate change, while mitigating emissions, is Hamburg which is in the process of developing HafenCity, currently Europe’s largest inner-city development project that will become a blueprint for the development of a European city on the waterfront.
HafenCity, located along the River Elbe, is being transformed from a mainly derelict, former dockland site into a lively city with a maritime environment that combines working, living, culture, leisure, tourism and shopping. The development, covering nearly 160 ha, will have 7,000 homes for 12,000 residents along with commercial developments that will offer more than 45,000 jobs. By the 2020s when it will be completed, HafenCity will have resulted in Hamburg’s city center being enlarged by around 40%.
Adapting to extreme weather
HafenCity lies in the south of the main Hamburg dike and therefore has no protection from storm surges. During the planning phase, it was agreed that surrounding HafenCity with dikes would create disadvantages for the district, including depriving residents and visitors of sight lines to the water as well as numerous technological and economic challenges of constructing a dike before any buildings had been constructed: hampering the successive development of the district.
Therefore, to protect itself from storm surges all buildings in HafenCity are built on artificially structured plinths Click & Tweet! that are compacted to a height of 8-9 meters above sea level. In the interior of HafenCity, the plinths provide ample space for underground carparks, reducing the amount of car parking space required in the streets of the new development. Meanwhile, to ensure vital infrastructure is out of harm’s way, all streets and bridges are sited at flood-protected levels, at least 7.8-8.5 meters above sea level, so even during a storm surge traffic within HafenCity, as well as between HafenCity and the inner city, can flow uninterrupted.
Mitigating emissions in construction
HafenCity has established an Ecolabel for buildings Click & Tweet! that realize sustainability in their designs including lowering of energy consumption. There are two types of Ecolabels awarded – ‘silver’ or ‘gold’ – to buildings that have achieved ‘special’ or excellent’ ratings in the five categories of:
- Sustainable management of energy resources: A significant reduction of primary energy consumption (well below statutory requirements) for running a building
- Sustainable management of public goods: For instance, advanced sanitary equipment to reduce water consumption
- Use of eco-friendly construction materials: Buildings must be free of materials containing halogen, volatile solvents or biocides and all tropical wood must stem from certified, sustainable sources
- Special consideration of health and well-being: Rooms in buildings need to have comfortable temperatures, contain non-allergenic fixtures and fittings and offer sound insulation
- Sustainable facility operations: Buildings should have low-maintenance requirements and have a monitoring certificate that shows the actual consumption of energy in the building’s first two years of operation.
In all cases, it is mandatory for buildings awarded an Ecolabel to fulfill the conditions of category 1 (sustainable management of energy resources). To receive Silver, buildings incorporate ecological qualities that generate either no extra costs if stipulated at an early stage of the construction process or additional construction costs if they are economically justifiable, while Gold-labelled buildings incorporate extraordinary innovative measures. Moving forwards, buildings that include residential uses will only be able to be built if they comply with the gold standard ecolabel.
Urban expansions can simultaneously adapt to climate change and decouple from resource use to mitigate emissions.
*Robert C. Brears is the author of Urban Water Security (Wiley), and of the forthcoming titles Blue and Green Cities (Palgrave Macmillan) and The Green Economy and the Water-Energy-Food Nexus (Palgrave Macmillan). He is Founder of Mitidaption, which consults on climate change risks to business, governance and society.