First prize

 

Author:
Dirk Krolikowski, Asc. Prof. Dipl.-Ing.
Falko Schmitt, Dipl.-Ing.
Jan Grimmek, Dipl.-Ing.
Steffan Robel, Dipl.-Ing.

Collaboration from:
Courtney Jones, Michael Huang, Betty Liang Peng, Lorand Goncal, Svenja Siever, Lara Prinz, Michael Baumgartner

Technical planning:
Structural planning Mayr | Ludescher | Partners: Dipl.-Ing. Hubert Busler, Dr.-Ing. Anne Bauer

DECISION OF THE PRIZE JURY:

 

The clear lines of this work are convincing and would draw in the attention of the visitor. The work emphasises the transition into the landscape and is emblematic in the form of the layered roofs that gradually increase in elevation. It is an inviting solution to the task, although the construction it requires is complex.

The development is understandable, albeit retrograde in parts. The planned lorry charging points are barely viable since the exit can only be used by reversing.

All car parking spaces are covered, as is the access from the parking spaces to the central service area. The short distances along the access paths to the central service area is welcomed, however the entry concept for this building requires some revision. The stark division of the service point into two buildings and the quality of stay between the two buildings were critically discussed.

The charging area results in a not insignificant area of sealed surface. The feasibility of the parking areas and the central connecting routes with turf joint pacing was questioned by the jury in terms of winter servicing (salt spreading) and shade. In addition, the needs of users requiring barrier-free access should be considered in the design of the topology. The establishment of long-term vegetation beneath the roof structure is also questioned and should be reviewed.

The proposed PV shingles are sensible given the large contiguous roof area.

The centrally located entry and exit routes between the two roundabouts also function in the event of slight tailbacks. The slightly modified trace of Christenstrasse has been sensibly designed, the meadow fringe to the west is welcomed as is the retention of a repurposed barn.

The charging station can be realised easily in two construction phases. The first phase of construction would then be fully functioning, and the sealed surfaces reduced accordingly.

The image of the gently floating timber wings in the landscape convinced the jury; the building will be a symbol and landmark for the site and for Kaeser as the sponsor.

 

Explanation of the design

Explanatory text

The maxims

The vision for the new Coburg Charging Station is a new generation of infrastructure that is sustainable, attractive and highly integrated. The perception and experience of the building clearly sets itself apart from familiar models of infrastructure, which it reinterprets on the basis of the interplay of architecture, landscape and the logic of the car as a mode of transport. With its independent identity, the new charging station represents a modern lifestyle and adheres to an innovative, integrated approach in defining the relationship of nature, technology and life. At the same time, the construction is instantly recognisable in order to live up to the site’s overriding urban ambitions and establish the new charging station in Coburg not merely on the basis of a high level of user experience but also because it stands out from afar as an elegant and striking form. The new charging station’s excellent architecture lives up to the exacting expectations of Kaeser and Coburg.

The logic of the new charging station

The construction is seen as part of the landscape and with the elegant, formal logic of the roof and building will become just that. The author has deliberately avoided prototypical, generic solutions and instead is pursuing a site-specific design to meet the requirements for integration and originality of the construction. The charging station roof sets an elegant pose extending from the topography of the landscape with which it engages in conversation.

While the ground plan shows the roof cubes arranged radially around the compartments forming around Christenstrasse, the roof looks out towards the areas of the main road in terms of urban development and presents a stand-out address. The sides of the modern timber construction have a plain geometry. The constant roof height over a 2% inclined floor level results in a differentiated interior space that is visibly not linear but compressed to the east by the changing height. The entrance area bids a high-quality welcome with its lofty dimension. At this point the roof and its PV skin come into view thanks to a fold that is also an active structural element and marks the driveway. The roof rises in the centre and expands the central charging garden. This links the user flow to the service buildings via a greenspace chain leading up to the open space of the upper parking area. The topography of the roof forms a differentiated space of experience that helps users establish their location and find their way. Breakout and hang-out niches can be found in the areas below the roof while the users appreciate the opportunity to access the service areas across dry ground. In the elevation, the morphology of the 12m high roof represents an exciting urban high point.

The silvery surfaces of the timber roof are created by PV shingles that adapt scale-like to the roof geometry and emphasise the geometry of the flowing form of the silver roof bands, which appear to be animated by the air, with attractive iridescent light reflections. This also highlights the energy conversion process. The warm tones of the timber construction below mark the internal space of the charging station and with their pleasing material nature contribute to the comfort of the public areas. Internal and external surfaces of the roof form are clearly distinguished by contrasting materials and support the spatial effect when viewing the roof construction. ETFE cushions filled with compressed air allow daylight to permeate and make a feature of compressed air as a construction material. When illuminated at night and in the dark these can act as torch-like pillows of light.

As the parking space and charging garden area are modelled on an accessible plateau with a 2% gradient, the topographical shift in the landscape is used to provide a lift along Christenstrasse. A kink in Christenstrasse provides space through this change in elevation to accommodate the self-service building and therefore integrate it optimally into the landscape at the level of the contour. The technical infrastructure and delivery areas are also integrated into this space and thus become a non-visible part of the landscape. At the same time, the building’s roof acts as a viewpoint across the campus and the attractive charging station with views of the surrounding landscape. There is a landscaped staircase that fluidly connects the charging garden greenspace chain with the park landscape. The charging garden greenspace chain is complemented by the upper open space in the park, around which a rich offer is focused, including e-bike hire and charging points as well as a play park. Users of the charging points and parking spaces are drawn into the park while the service areas are made accessible to the user groups from the landscape park side.

The new, contemporary interpretation of infrastructure in connection with identity-forming architecture and an elegant silhouette produces a special location, a landmark that is readily recognisable. The high level of integration demonstrates how innovative technology and modern lifestyle can combine in a new generation of infrastructure. With high expectations for sustainability and therefore a construction culture with a significant sustainability component, the new charging station is pioneering and representative of the Kaeser brand, efficiency and passion, and for the city of Coburg.

The roof and its construction

The canopies of the EV charging station unfold to the sides from flat, delicate and almost horizontal surfaces in cross-laminated timber with a central skylight formed by a continuous widening translucent opening. At the heart, the roof surface, which is designed as a torse, continuously reaches upwards to a height of approximately 12m above the ground towards the new 2205 main road and at the same time bends slightly in a V-shape on both sides, creating a spatial, three-dimensional form that blends harmoniously into the site area. The bearing structure has been investigated and verified in respect of all significant load cases using a computer model. The roof supporting structure consists of a longitudinal supporting structure arranged in the centre next to the skylight with two main cross-laminated timber beams spaced approximately 1.0m to 4.7m apart over a length of approximately 105m and 130m, the height of which is adapted to the moment progression. The longitudinal supporting structure is supported by V-shaped inclined cross-laminated timber columns clamped on both sides and resting on reinforced concrete foundations. In the transverse direction, the 10cm thick cross-laminated timber panels of the roofing are supported by cantilevered, haunched cross-laminated timber cross beams at intervals of approximately 4m, which are connected to the longitudinal structure at the same height via steel connection plates to prevent bending. The three-dimensional shape also supports the cantilevers in the centre area, as this activates a shell load-bearing effect of the solid cross-laminated timber panels and a spatial load transfer. In the area of the flat overhangs at the roof ends, the cross-laminated timber panels are doubled to 20cm thick panels on the top side to increase rigidity. To provide horizontal bracing, the higher roof to the north is angled downwards at certain points, creating additional support and stiffening of the roof structure in the transverse direction in the event of wind loads. Preliminary vibration analyses have shown that the first natural frequency of the roof structure is 1.60Hz. In the subsequent planning phases, the stiffness ratios can be optimised and more detailed investigations of the dynamic wind load components caused by height-induced vibration components can be carried out. In order to optimise the component dimensions, this can be supplemented by wind tunnel tests and analysed in more detail using computational fluid dynamics simulations (CFD simulations). Experience has shown that the dynamic wind load components will only occur in the unblocked state. In the blocked state, which is decisive for the design of the components, no increase in vertical wind loads is to be expected. The roofing consists of PV shingles that can track the radii of the single-curved cross-laminated timber panels. The light slot is covered with ETFE cushions. With the timber roofing and concrete substructures, materials are chosen throughout that are robust, durable and fully recyclable. The cubic volume of wood used in the roof stores almost the same amount in tonnes of carbon dioxide and removes it from the environment, while at the same time substituting other emission-intensive materials through the use of wood. The roof structure can be prefabricated in the factory on a large modular scale. The individual parts are transported by road and can be lifted into place using a mobile crane. This achieves a desirable high degree of prefabrication in the factory with effective use of machinery and reduces assembly times with corresponding weather influences to ensure quality.

Traffic areas

The locations of the entrances and exits are strategically positioned away from the roundabouts to avoid traffic jams at the entrances. Firstly, there is a large orientation area on the site where the driver is shown a parking space via an information system. The lanes are set at a comfortable 6 metres for two-way traffic. Water-permeable asphalt is planned for the surfaces to counteract surface sealing. Grass paving is planned for the parking spaces, which is only partially sealed. In the walkable gaps, the grass paving compacts into pavements that diffuse laterally into the green areas. The strip-like system of grass joints adapts to the logic of the architecture and translates the theme of air currents into a striking floor pattern. Freely scattered small trees and interspersed seating elements bestow a garden-like character on the area below the shady roof. The selection of tree species is adapted to the available height under the shade canopy. Lorry parking spaces are arranged in the green apron area and coordinated with the necessary towing curves. Covering the lorries is not considered appropriate.

Expansion stages

The charging station roof consists of two structurally independent roofs. These can be constructed in phases. The first phase comprises the roof that is directly adjacent to the service buildings. It should be borne in mind during the planning process that the additional costs for roof structures are by no means linear and that a full fit-out could already make sense in the first phase. While the long-distance urban image of the larger roof elevation only unfolds its full power in the second phase, the roof is nevertheless effective in terms of urban development and fully active architecturally. The buildings are shown in their possible final stage of development, but are also flexible in size as they are embedded in the slope.

The charging station area and the outdoor facilities

The design approach views both the new charging station and the entire park area as an opportunity to strengthen the existing location in the northern industrial estate and to create an important urban link between the neighbouring urban structure, the landscape areas and the Goldbergsee lake. With its open space qualities and range of uses, the new charging station acts as a link and makes an important contribution to the integration of the commercial campus into the urban open space structure. Sweeping views as far as Schloss Callenberg and the Glenderwiese nature reserve strengthen the connection with the surrounding area.

A network of paths, which formally detaches itself radially from the course of Christenstrasse, stretches out greenspace cells that condense into a neural point at the square by the park steps. Towards the edges, these cells dissolve into larger-scale meadow segments, thus mediating the urban space between the urban core on the square and the large-scale nature of the neighbouring commercial structures. The strong interpenetration of landscape and architecture seeks a close relationship between mobility, urbanity and landscape. The result is a place that stands out thanks to its creative power, but also thanks to the variety of uses embedded in a park-like infrastructure. There are constantly changing views, not only for motorists but also for cyclists and pedestrians in particular; depending on the angle of view, the complex presents itself either architecturally or scenically.

The slightly modified course of Christenstrasse enables the different areas of the entire park to be dovetailed precisely. The striking bend forces a change of direction and deceleration at a central point. The service building forms the interface between the accessible areas with charging infrastructure and the park-like areas where people can take a break. At the same time, it mediates the difference in height between the two levels – to the west as green topography and to the east as an architectural façade. The processes of arrival, charging and relaxing are closely interwoven and well coordinated. Depending on the length of stay, the user either shuttles only briefly between the EV charging point and the self-service area or uses the neighbouring parking infrastructure for a longer stay. While the car park with charging infrastructure celebrates arrival and the dynamics of movement, a green haven of peace is being created here in the centre for lingering and slowing down. The open spaces below the roof of the charging station form a greenspace chain that leads the user through the charging garden via the car park stairs with integrated, accessible ramp system to the upper level. The user is thus guided fluidly into the park. A central feel-good square in a green setting with a high quality of stay is being created here. The programme uses are concentrated at this central point and are accessible to all user groups – service area with café/shop, e-bike station, children’s playground, outdoor gym equipment, as well as relaxing garden-like areas. At the same time, the square is an anchor point for users from the surrounding areas, inviting them to pause for a moment and allowing them to use the self-service areas. The extensively greened roof surfaces of the buildings, which slope towards the park, also offer viewing terraces over the site and the elegant roof shape.

Another potential centre of attraction within the park is the barn at Hessenhof in the southern part of the park. Here, the park’s programme is seasonally expanded and enriched with conceivable uses such as the Hessenhof pop-up food festival, petting zoo, art gallery with temporary studio spaces and an open-air cinema, for which the barn serves as a projection screen.

Outdoor space materials

The parking spaces are made of grass paving and give the normally very functional areas a green, park-like character, focused in a central lane with small trees and integrating individual seating elements. The permeable pavement surfaces allow partial rainwater infiltration on site with infiltration systems placed underneath. The former Christenstrasse will be rebuilt as a combined footpath and cycle path with a width of 4 metres, made of light-coloured asphalt with mineral grit that is easy to roll over. The finely branched side paths made of water-bound surfacing create a park-like feel. Concrete upstands create isolated seating areas and pick up on the tectonics and design language of the self-service building. The green areas at the sides are designed as shallow infiltration troughs and allow rainwater to accumulate, especially during heavy rainfall, and regulate heat through evaporative cooling. By removing existing asphalt surfaces, the proportion of sealed surfaces is significantly reduced. The valuable tree population along the former Christenstrasse will be preserved as far as possible and will form the core of the new climatic forest. Complementary shrubs condense the linear row of trees into a flat, shady grove. The dense shrub layer is removed in favour of a new clarity. The transition to the neighbouring industrial estate to the west is defined by a meadow border consisting of different seed mixtures of field margin perennials and meadow herbs, which picks up on the atmosphere of the neighbouring field structures. The geometry of the park is supported by a subtle patchwork of varying colour tones.