Wadden Sea Centre | Dorte Mandrup Arkitekter

The Wadden Sea Centre

The unique Wadden Sea intertidal zone is a joint venture between human enterprise and the dynamic forces of nature. Since the Iron Age, humans have chosen to settle here at the edge of the generous marsh lands on human-made hill islands – created for protection against the tide. Viking farms and villages, built out of wood and thatched with straw, were opportunely placed here, close to Ribe, the first trade city in Scandinavia.

The Wadden Sea Centre is an extension to an existing, angled exhibition building from 1995. To ensure a cohesive layout and an easy flow, the extension has been designed to partly embrace the existing building in order to create a larger sense of unity. The four-winged farm typology refers to the original buildings of the region.

Traditional and regional craftsmanship

The use of water reeds as cladding for roofs has been in use since the Viking Age – and the craftsmanship remains essentially the same. From a distance, the exhibition centre has the appearance of a large thatched farm emerging as an island in the landscape. The soft, textural reeds are sculpturally processed with long precision cuts in order to create eaves, covered areas, and intersections between diagonal and vertical surfaces.

The entrance is placed in continuation of the existing building’s gable. This ensures a circular flow in the exhibition, easy connection to the existing café, and a meeting and service area with the least possible amount of conversion. A sense of arrival is conveyed with a diagonally positioned ramp leading to a covered terrace that runs the full length of the building.

Conjoining exhibition and architecture

The exhibition depicts life in and around the Wadden Sea including the cycle of migratory birds through 7 different rooms and themes.  It is shaped by various spatial geometries and moods. Different types of daylight and connection to the outdoor spaces is an important part of the experience. The exhibition space has been created in collaboration with the exhibition architect to create the optimal interplay between exhibit and architecture.

The teaching area has two large classrooms and outdoor storing spaces for equipment.  It is placed so that teaching and field work have sufficient space and access to the outdoor areas. Two covered areas provide shelter for students and large groups to convene and eat their lunch.

The existing brick building is clad with wooden slats on both the roof and the facades, and new and differently proportioned oak windows have been added to enhance the building’s visual coherence.

Technical description 

The existing building has been both extended and rebuilt. The constructional principle of the existing building is a steel-frame construction that carries both the roof and façade, with the infilled with masonry partitions and small window-openings. The brick-facades of the existing buildings have been rebuilt by changing the formats of windows in order to adapt to the overall expression of the new building, but apart form that the existing facades are left unchanged, but have all been clad in wood.

In the extension, the principle of the steel-construction has been maintained, only with partitions of prefabricated insulated wood-cassettes instead of brick. Furthermore the steel-frames are hidden in the construction in the new building as opposed to the existing building where all steel is visible.

The new education-building has a wooden construction including the roof, which has been formed from a system of wooden trusses. The facades consist of partitions of prefabricated insulated wood-cassettes. The attic is unheated, so the insulation is horizontally placed above the ceilings.

The extended exhibition-building as well as the education-building are clad on all facades and roofs with either thatched straw or wooden slats.

Exterior surfaces

In regards to the extensive use of thatched surfaces, especially the large overhangs, experts from both Denmark and Holland have been involved in developing the different solutions of the design. Special focus has also been given to the fire-issues of using thatched surfaces to such an extent. All surfaces are therefore fire protected with a special build-up behind the straw, as well as the surfaces around main access-ways and fire-escape routes, which have been treated with a fire-retardant on the actual surface of the thatch. The amount of thatched surfaces is 2.600 m2, and 25.000 bundles of thatching straw have been used. The straw has been harvested locally in two different inlets nearby.

The wood-cladded facades and roofs are done with the use of Robinia, also called Black Locust. The cladding has been pre-patinated and mounted with a distance between the surface behind, and integrated hatches for servicing the gutters etc. Underneath the cladding, the roofs are constructed as a traditional roofing-felt build-up.

Robinia is a high-density wood forested in central Europe, and requires no further maintenance. The slats will continue to patinate towards silver grey over time. 3.200 meters of wooden slats have been used in the process.

All glass-partitions are framed with oil-treated oak.

The boardwalk and terraces are clad with Thermowood, a heat-treated pine that is naturally impregnated. 

Interior surfaces

All new floors are cast concrete. Walls are made up of a plywood-enforced, light steel wall with gypsum board surface. The ceilings in the exhibition spaces are acoustic plaster, while the ceilings in the new education-building and secondary spaces in the exhibition have been fitted with sound-absorbent ceiling-plates. 

Sustainability

The choice of materials and overall design solutions reinforce the concept of the building growing out of the landscape. The thatch itself is one of the only materials that you can use directly as is from nature, as a durable building-envelope. The durability of Robinia makes it easily comparable with exotic hard-woods, but without the risk of further contribution to rainforest deforestation. The choice of a light structure, primarily in wood, further minimizes the environmental impact of the building.

The wall and roof build-up, the carefully placed windows and skylights etc. are a result of both the exhibition demands as well as an ambition to lower the energy consumption of the building, which means that without the addition of solar-panels or similar active measurements, the building has a consumption of 40 kWh/ year.

Architect - Dorte Mandrup A/S

Landscape Architect - Marianne Levinsen Landskab ApS

Engineer - Steensen & Varming and Anders Christensen ApS