AZPA . SpreierTrenner Architekten . Restricted Competition. Finalist
Our proposal for the Wedel Kraftwerk is an attempt to resolve the conflict between the natural ecology and the manmade environment.
An Experiment in Ecological Aesthetics
The harnessing and deployment of energy and its intersection with the natural ecologies is perhaps the central question of the civilization we inhabit. It is therefore crucial for Vattenfall, a corporation that is vested in the generation and distribution of energy to address this question, not only as a technical problem, but also as an aesthetic and cultural subject. We need to develop technologies that will make the artificial part of the natural ecosystems. This project is aimed at providing Vattenfall with an aesthetic manifestation of a new integration between manmade processes and the natural environment. It would be a mistake for the facilities to appear as industrial facilities, emphasising their artificiality through the use of steel and concrete and sharp geometries. On the contrary, our proposal gravitates around the possibility to make the the artificial as close as possible to the natural, by designing an envelope for the Wedel Vattenfall plant which will appear as continuous with nature, while being economic and efficient. In short, we have tried to produce a camouflage strategy for the new plants, which we hope to convert into a giant topiary game, of a scale never seen before, a green mountain surrounded by dense vegetation.
Our proposal has been generated from an array of specific considerations, including Vattenfall’s profile as a leading energy company, its specific location in Wedel, and its relationship with the landscaping and public operations being developed along the banks of Elbe.
Wedel Kraftwerk occupies a significant site. Its location on the banks of the Elba, its climate and the activities which take place there… this intervention will be crucial to the town of Wedel and to the region of Hamburg, creating an important landmark for Wedel.
A crucial consideration for the project has been its ecological performance. The project will contribute in terms of architecture, urbanity and landscape to the consolidation of this site as a place for high environmental performance and quality. And also this intervention should bring back something to the citizenry in terms of environmental quality, architecture, landscape, and public space.
Other considerations have been of economic and technical nature. Within these considerations, the economic viability (by applying adequate resources both in capital investment and in maintenance), energy conservation and sustainability have played a decisive role in the design of the proposal.
Green Cloud
Our first concept departed from the idea that we could produce a corrugated envelope to the new plant, made from creepers which could absorb a substantial part of the carbon emissions of the plant because of an increased surface area, produced by a corrugation of the green envelope. The green envelope will become a green mountain, a giant topiary, using the geometry of the future complex as a departure point and using corrugation as a structural device to stabilise the new envelope. Given that this green envelope will require some research in terms of its maintenance costs, our current proposal retains the aesthetic qualities of this concept and replaces the vegetation of the façade by a green textile structure. Our proposal allows for Vattenfall to develop research on the possibility of making the membrane literally out of vegetation. The geometry of the envelope has been designed to allow for the progressive replacement of the green textile by vegetation in the future, once the investigation has taken place. The geometry of the envelope has been designed to be easily replaced by a wiremesh for the creepers to climb on.
Landscape: An Artificial Ecosystem
Our proposal for the landscape is to maximise the presence of nature as the new image of the plant. We aim to bring back the original ecosystem that once populated the margins of the Elbe: the riparian forest. This type of vegetation is also one of the most avid consumers of CO2 and we believe there are real advantages to the use of this ecosystem as the image of the new Wedel plant.
The environment of the Kraftwerk must be integrated into the “nautical mile” of the Elba, and therefore with its gardens, viewpoints, bike routes… Our aim is for the Kraftwerk to become not only integrated in this emerging public real, but to become one of its main features. We have given serious consideration to the preservation of the historical remnants of the old plant, where the historical and emotional memory of the community is vested. Respect for this historical memory, while maximizing economic viability has led us to propose an intervention that integrates as many elements as possible from the existing plant. One of our proposals is to preserve the two existing chimneys, thereby retaining a familiar trait of the local landscape, while saving the cost of demolition.
Our proposal is to create a densely packed riparian forest with the local vegetation of the banks of the Elbe around the Powerstation, both as a carbon sequestration device and as an aesthetic device, making the powerstation into a large green cloud which will become a new landmark in the Wedel skyline. This riparian forest will follow the spirit and extraordinary environmental quality of the Stadtpark in Hamburg, which is configured as the city’s Central Park.
This strategy will be followed around the station, and will act as a backdrop to the public spaces being developed along the banks of the Elbe. We propose to deploy this strategy throughout the central area, if and when it does not interfere in any way with the normal activity of the Power Station.
In controlled and restricted areas of massive tree clusters, we have considered the implementation of a system for the growth acceleration by using controlled emission of CO2 from the power station, conveniently filtered and cleaned.
Retrieving the Riparian Forest
The riparian forests that once populated the banks of the River Elbe were swallowed by industries, especially in this area of Germany. Our proposal wants to retrieve the primeval ecosystem and integrate the new buildings with it.
The riparian ecosystem will provide a high environmental quality while mitigating the plant emissions. For that reason, we have tried to maximize the green area in the plan, and maximized the density of trees too. We have used an agent-based algorithm to calculate the overall number of trees, fed with the natural parameters of growth, to calculate the maximum number of trees to be planted around the plant. The densely packed tree planting is a strategy of CO2 storage and carbon sequestration, which relates to the overall ambition of optimizing the environmental performance of the complex, while generating an environmentalist aesthetic. Fast growing trees such as poplars will be planted for CO2 sequestration and replaced when mature, giving to the project a temporal dimension, and possibly a participatory one. Projects like the 7000 Oaks, initiated by Joseph Beuys in Kassel in 1982 are a precedent to our strategy, which in Wedel will be aimed to replicate the primeval ecosystem of the Riparian Forest, which does not need any maintenance, as it was developed for centuries without human interference.
We have designed the plantings to produce large masses of trees of the same species, growing around the new building in a gradient of height which will minimize the visual impact of the buildings. The gradient of tree species from tall to short, as we move away from the building, will contribute to diminish the visual impact of the plant buildings.and the tree packing will also be developed over time. The taller trees in the riparian ecosystem, the poplars, will be planted closer to the building, and the different species will create a diminishing gradient of height for the tree masses, creating a layering effect of the trees around the new buildings. The last layer, the green undulating surface of the building’s envelope will represent the tallest green mass in this sequence of green masses, as if it was the tallest mass of vegetation in the new riparian forest that is to become the new image of the Wedel Power station: a giant topiary work which will become a landmark in the city’s profile.
Species
The site will be hosting a selection of local species. It will become a miniature forest of the surrounding region. The distribution of the species in the site happens in a gradated fashion radiating from the factory. The plant building will become the central green mass, defining the peak of the green forest, from where the species are gradated towards the periphery of the site, where the more public uses will be located. Large/tall/high foliage trees will blend with the proposed green skin of the factory. As we approach the riverbank in the South and the railway pedestrian pathway in the North, the scale of the trees will decrease introducing species that relate more with the public scale such as fruit trees. We intend to keep as many existing trees.
List of species:
Small Scale (2-5m)
Prunus avium ‘Kassins fruhe Herzkirsche’
Malus domestica ‘Alkmene’
…
Mid scale (8-12m)
Aesculus x carnea
Acer Platanoides
Betula nigra
Betula pendula
….
Large scale (12-20m)
Salix Alba
Salix Alba ‘tristis’
Alnus glutinosa
Populus nigra
….
3 areas of intervention:
Private area:
Kraftwerksgelände Südteil / the factory, the green peak:
We propose to minimize the hard surface areas (Even parking areas 1/2 green pavement)
We have kept the existing topography to minimize costs.
The two entrances (the one to the North is more logistic while the main personnel entrance is to the West adjacent to the Machine hall) will be framed with the trees defining view corridors framing views to the factory.
The limits of the site will also be formalized as a green hedge, consistently with the overall aesthetic intent.
The brief asks for 5000m2 of hard surface to store machinery every 4 years which is to be located in front of the machine hall. We propose to use this area for public uses with temporary fences, and when required the fencing will be replaced and moved to the Southern perimeter until this area can again be recovered for public use. In order to extend this area in front of the Machine hall, the position of the car park has been rotated and shifted a bit towards the north.
Public areas:
Pedestrian walks (connecting the housing area to the West – Wohngebiet am Elbhochufer and and the new office area to the East –Business Park Elbufer.
Elbpromenade – the Dyke Walk,
We have designed the Sudteil and Elbpromenade as a single unit of ladscape. In this area there will be 2 main walkways:
The dyke walk/cycling path
In order to avoid flooding in the factory, the topography has been manipulated to raise 7.5m above water. This new topography, will create a sloped public space, and in its crease a walkway will be proposed: the dyke walk. From this pathway, it will be possible to enjoy 360-views to the water, to the business park etc..
-The riverside walk. This pathway by the water will create a continuity with the proposed walkways towards the East and West.
In the space between these two pathways, most of the public activities in the area will be located:
– Leisure park
– Beach
– Ships, nautic area
– Markets
– Performance areas
-…
In order to maximize the public areas, in the concrete arena in front of the machinenhall (where the brief asks for 5000m2 of hard surface to store machinery every 4 years) we propose to introduce a sport leisure park.
– Football pitch
– Tennis Courts
– The Machinenhall facade, green wall / climbing (wall) The east façade of the old turbine building will be covered by a climbing wall.
The configuration of the pedestrian promenade will refer the presence of coal at the site through the use of materials which reflect this pre-existence.
Krafwerksgelände Nordteil – Rail Walk:
Northern pedestrian pathway, area of recovery of rail tracks. We choose to seamlesly introduce the pedestrian paths in this area keeping the traces of the tracks.
Architecture
The new plant will have a notable presence in Wedel’s profile because of its sheer volume and the proximity to the river. This is a great opportunity to create a new landmark for Wedel, which will become a reference for the banks of the Elbe in respect to the city.
This is the reason why our proposal attempts to make a single yet complex entity from all the different parts of the plant. Like a cloud, like a mountain, like a forest… A fragmented approach will only insist in the artificial quality of the facility, an aesthetic of assemblage. Our green cloud relates to the forms of nature, which are systematic yet differentiated. Our proposal is to achieve a unified image of the different parts of the plant, with a geometrical system capable to adjust to the different conditions, like a cloud adjusts its shape to the thermodynamic patterns of the atmosphere. A pliant geometry, suitable for growth and differentiation will provide a highly expressive form, while preserving the capacity for growth, dialogue with the immediate natural environment, and change.
Our proposal is to wrap the volumes of the plants with a skin capable of providing a clear identity, and to relate to the landscape patterns in the surroundings. as efficient as possible in terms of economy, maintenance, and sustainability.
For this purpose we have chosen a textile skin, a thin film with a high degree of permeability to permit illumination and ventilation of the interior spaces of the plant where necessary. The wind resistance will decrease with this permeability, and thereby minimize the sizing of the support structure of this textile envelope. This veil will give to the formal solution a large expressive potential. This is a solution which may come to resonate with local specificities as the undulating surface of the Elba, the sails of pleasure craft, and the colours of the local fields.
The characteristics of this textile finishing guarantee its performance in terms of safety and durability. The choice of colour and finish will be realised according to their ability to integrate into its appearance the effect of time.
The formalization of the surface will be made by the textile double curvature. This optimizes the functioning of the solution in terms of finish and structural optimization
As a standard solution, our proposal for the building envelope consists of a first lightweight enclosure of prefabricated sandwich panels fixed to the structure of the plant. These panels will adapt to the acoustic and thermal insulation performance that the plant requires. Then we will place a galvanized steel substructure as efficient and light as possible on which we will tense our textile coating.
This standard solution is organized in a strata of horizontal bands coating the building mass in order to provide it with a unitary image from any subjective viewpoint. The base of the façade is in reinforced concrete up to a height of 4.5m, where the standard solution of envelope textile begins.
Green Cloud
The economic efficiency of the building envelope, which stresses the fabric in two directions to avoid deflection an rippling of the surface, introduces an organic geometry which turns the severe and artificial geometry of the industrial facilities into a more natural, curvilinear geometry which modulates the scale of the facility to the scale of the trees that will be planted around the building. It is a strategy of camouflage, where the massive volume of the plant is turned into a green cloud of ambiguous profile and a tree-like scale and colour. The curvilinear geometry used in the structural solution resonates with the fluvial nature of the landscape on the Elba, associating itself with the organic qualities of the surrounding landscape.
The color of the fabric will mimic the surrounding landscape, and ensure that lasts for a long time without much cleaning. The green mesh, frequently used in garden enclosures and agricultural furniture will not get dirty easily, and will resonate with the agricultural spirit of the proposal. Other possibilities of colouring, perhaps using printed DPM patterns on the fabric, may be investigated further.
Data sheet
Wettbewerbsverfahren GuD-HKW Wedel
Restricted Competition: 2013
Finalist
Cost: Façade:18M € Landscape:4.5 M€
AZPA Team: Alejandro Zaera-Polo, Maider Llaguno, Pep Wennberg , Robert Berenguer, Ravi Lopes Calamita, Pere Raventos, Charles Valla, Guillermo Fernandez-Abascal, Manuel Eijo, Valle Medina.
Landscape Architect: RAINER SCHMIDT LANDSCHAFTSARCHITEKTEN
Local Partner: *SpreierTrenner Architekten
