The new Bahnstadt district counts 116 ha and is thus larger than the historic city centre of Heidelberg and is one of Germany’s largest urban development projects. The public open space concept KOER is based on an urban masterplan by Trojan & Trojan, which envisages a large proportion of high-quality public spaces with sub-regional appeal and strong individual identities, applying green and resource-saving construction methods alongside stormwater management. Therefore the character of these new public open spaces of 29 ha played a key role in this transformation process from former railway tracks and US military sites into a neighbourhood of short distances. They offer easy access to nearby train and tram way systems, connects to existing urban structures and to superior cycle speed paths towards West- and Südstadt, Bergheim or Pfaffengrund.
Some uncontaminated existing elements were preserved in their authenticity. Soil components were connected to natural areas and ecological habitats. The KOER concept takes into account resilience issues such as amelioration of health factors and microclimate, heat equalization under given conditions, rainwater management, ecological compensation measures, infrastructure and development, recycling of materials and constructed elements, energy saving topics, phasing and costs.
Since 2005 striking open space qualities for a vibrant coexistence of the 12,000 residents and workers were created along former railway lines, in the spirit of Heidelberg's cultural urbanity. Besides the white, sustainable building structure, these linear green spaces shape the new identity for this neighbourhood. KOER supports social aspects for lively neighbourhoods with activity offers in their direct surroundings for people of all age. From the very beginning of this project citizens were involved in participatory processes.
Today a network of continuous open green spaces characterise the sector: the linear park promenade, which follows the former elevated railway embankment, with residential streets connecting to the Lange Anger. Tree structures try to balance the rather dry-warm in microclimate from the historic crushed stone layer of the former railway body. The new and parallel Lange Anger is water-articulated and tries to equalize climatic conditions in the hot summer months with it’s rather cool and shady character. With it’s increasingly growing tree canopies it will develop into a synergetic antipode to the promenade over time. The rainwater of the neighbourhood is retained to 50% on site and connected to the 9.5 m wide water channel, which does not only attract children and wildlife. This sustainable linear park offers new urban qualities in resilient green spaces with changing seasonal aspects, that bring people together and convey identity.
A multifunctional, communicative activity strip follows the linearity of the former railway tracks in a resource-saving manner. Lawns and play areas and positioned along the main promenade on the edge of the urban development. A long continuous retaining wall made from tamped concrete protects the elevated gardens of the residential blocks. It forms a hard architectural edge that defines the interface between private and public spaces. Playgrounds with different themes expand into parcours of movement. Historical railway relics were creatively integrated. The choice of trees and shrubs was adapted to climatic and specific regional conditions, e.g. even thermophile species like Ficus carica, Morus alba or Albizzia julibrizzin could be planted.
A curved seating step mediates between intensively used zones and ecological compensation areas. It separates the usable upper lawns, from the rather inaccessible lover ecological corridors for fauna and flora of thermophile habitats.
Objectives: Park and action area, increase of ecological diversity, equalizing the microclimate of hot summer months by shade of trees in green areas and streets, securing protected fauna and flora.
Lange Anger的蓄水池收集了屋顶和庭院的雨水，超出其蓄水量的雨水将通过过滤区系统渗入地面。50%的降水被保留在步道附近的地面上。纵向延伸的宽阔水渠，映衬着蓝天白云。水渠面积达5000平方米，东连Königsstuhl，西向Eppelheim方向的落日。四季变化，新建成的城市公共空间为居民提供了户外亲水空间、林荫纳凉场所甚至冬日打户外冰球的可能性。
The water reservoirs of the Lange Anger collects stormwater from roofs and courtyards and lets excess water seep into the ground via a system of infiltration areas. 50% of the precipitation water is retained in the grounds of neighbourhoods of the Promenade. The view along the wide, elongated water surface reflects the sky and covers 5,000 m². It is directed towards the Königsstuhl to the east and to the setting sun to the west towards Eppelheim. Throughout the year, new spatial qualities offer outdoor spaces near the water and in the shade for resting or to be used, e.g. for ice hockey in winter.
目标：创造新的微气候，减少热量吸收，通过植被增加降温效果和生物多样性。
Objectives: Creation of new microclimates, reduction of heat absorption, increase of cooling effect and biodiversity through vegetation.