STEP Berlin Climate adaptation in the growing city

Berlin has to become more resilient. Adapting the city to climate change is crucial for it to grow without losing quality of life. Berlin has to be designed in such a way that heavy rain no longer leads to flooding and that people and nature can survive even long periods of heat. StEP Klima KONKRET shows how this can be done - with detailed information on which measures make sense in which environment. The growing city offers a unique opportunity to implement this adaptation. Where there is a lot of building and rebuilding, adaptation measures can be taken care of without too much effort - as a piggyback. The prerequisite is that everyone involved in planning and building cooperates: in administrations, authorities, planning offices and in the real estate and construction industry. Climate adaptation is a task that concerns everyone - and from whose solution everyone benefits.

StEP Klima KONKRET supplements the 2011 Urban Development Plan on Climate by deepening and profiling its contents (which remain valid) and providing practical guidelines. It incorporates the latest findings from research and pilot projects on adaptation to the consequences of climate change, also from Berlin.
The guiding principle of the compact city remains unchanged. The task of urban development in Berlin is to decouple the growth of the city from negative consequences. Further densification does not stand in the way of adaptation. The fact that a lot is being built even opens up the opportunity to realise adaptation measures on a larger scale: "piggybacking". Here, the focus is not on sectoral climate adaptation measures, but the entire surface of the city becomes space for action for the water-sensitive and heat-adapted city. In the sense of multicoding, climate adaptation becomes one task among many in shaping the surface of the city.

Focus on heat and flooding
Urban heat (heat days/tropical nights) and urban flooding (after heavy rain) are core tasks of adaptation: both weather extremes will occur more frequently in Berlin due to climate change. Coping with them is essential to safeguard the quality of life in the city. The heat-adapted city and water-sensitive urban development are becoming key issues.
Key strategies against urban heat are: ventilate, shade, increase back radiation, cool by evaporation. New buildings should leave paths open for air exchange, architecture and trees should provide shade, and bright, smooth surfaces of buildings and surfaces should prevent heating up. New feel-good spaces are being created.
Above all, however, it is important to intensify cooling evaporation. This task is performed by trees, urban wetlands, vegetation and soils, which must be sufficiently supplied with water. This is not limited to public and private open spaces. Roofs and facades play an equally important role; in street space, evaporation beds or unsealed verges can support cooling.
The key strategies of water-sensitive urban development are: infiltration, evaporation, storage, retention and discharge via emergency waterways. This also relieves the combined sewer system, prevents overflows and thus benefits the water bodies.
The task is to transform the surface of the city. Buildings, courtyards, streets, squares and green spaces should - according to the principle of the sponge city - also absorb heavy precipitation. Emergency waterways divert surpluses from residential and commercial quarters to less sensitive areas. From there, they flow away with a delay. Roofs and urban wetlands store water even longer - as a resource for dry summer periods.

Concretisation according to development structure
Bundling adaptation opens up synergies: measures work best where they interact systemically and are coordinated with the location. For this reason, StEP Klima KONKRET develops bundles of measures and strategies for seven common building structure and area types in Berlin, for example, dense perimeter block development, new multi-storey residential buildings and streets and squares.

Integrating adaptation
To accelerate implementation, StEP Klima KONKRET focuses on integration. The goal is adaptation in the form of no-regret measures that make social, economic and ecological sense even without climate change. Therefore, StEP Klima KONKRET also names instruments and ways to integrate adaptation into processes, programmes and projects at all planning levels.
Adaptation also requires an interdisciplinary approach: it addresses all disciplines - from housing to transport or wastewater planning. Reference projects serve as models and pilot projects. Examples and calculations provide argumentation aids to increase the acceptance of adaptation measures.