Gastronomy in the hall of Asher
Located on the outskirts of Lengwil, close to Lake Constance in north-eastern Switzerland, is the Ekkharthof Community and Gastronomy Centre. Set behind thick hedges the Ekkharthof settlement only becomes visible after you've turned off the motorway onto the narrow country road. At first, a chimney stands out, before behind it stands a pillared hall made of ash wood sitting on a raised concrete base that grows out of the gently sloping terrain: the new cantina. Massive, angular pillars support a widely cantilevered roof. The massive wooden construction - almost thirty meters long and fifteen meters wide - appears open and light.
In the 1970s, the Ekkharthof healing and educational center was built in Lengwil in Thurgau. Around two hundred people in need of care live and work here in the centre organised around Anthroposophical principles. In addition to a special school, a dormitory, and numerous workshops, there is an estate business, from which a large part of the food for the restaurant comes from. For a long time the community sought and worked separated and secluded from much of society. Over recent decades, however, the care philosophy has changed - from one of isolation to openness and inclusion. When, after 40 years of operation, the buildings were supposed to be adapted to new requirements and legal regulations, there were concerns from the sponsoring association that the intended opening of the facility would also be structurally visible.
A selective competition was launched for the renovations and new buildings with a total value of CHF 24 million, in which Zurich studio, Lukas Imhof Architektur’s design, impressed the jury. At the end of 2018, after the first construction phase, the restaurant building was put into operation. The cloakrooms for the staff as well as the technology and the storage rooms are in the basement he housed etc. Chef Manuel Müller guides you through the cold rooms, in which fruit and vegetables from the farm, sacks of herbs and also milk and yoghurt from our own dairy are stored. Cooking takes place in the gastronomy kitchen on the basement floor, where Müller and his twenty-person kitchen team prepare menus for around 300 people every day.
A large part of the food is distributed directly to the living groups. In the cantina, up on the mezzanine floor, the staff and loyal guests who come from outside eat. The dining room has around 200 seats.
Like a barn, the interior is symmetrical and the canopy is pulled down towards the inner courtyard so that it covers the terrace. The massive frame structure made of ash is self-stiffening, and the walls have been completely waived. Due to this rigidity of design, the stress on the frame corners, which also act as nodes, is particularly high. Accordingly, the geometry of the components is stronger above the supports - the form following this logic, creating space for metal connectors and is at the same time an architectural expression.
This principle is particularly evident on the protruding canopy. Towards the front, where the load is low, the four girders and roof supports taper both in height and laterally. The girders run continuously from the inside to the outside. In line with the windows, the beams are double and insulated in between. Extra-wide window frames also prevent the thermal bridge, which means that the required energy efficiency is maintained.
When asked about the special features of this construction project, Christoph Angehrn, project manager at Kolb Ingenieure, knows how to point out numerous details, such as the structural wood protection. Although the canopies protect the structure from moisture, the connection between the supports and the exposed concrete masonry had to be detailed so that rainwater would run off. The builder and carpenter had to set the steel parts very precisely because the wooden supports did not allow any tolerances at the top. Accordingly, a lot of communication was required on the construction site. “Even if it looks simple at first glance, almost all the support legs have a slightly different geometry,” says architect Lukas Imhof, describing the complexity of the construction.
It was clear early on in the project that the design should be implemented with wood. The structures would not have been possible in either concrete or steel. Hardwoods have strength values that are higher than those of construction woods made from softwoods, such as Norway spruce, which are most frequently used today. Above all, the transverse compressive strength and the transverse tensile strength, but also the shear and tensile strength parallel to the fibre are significantly stronger than the softwood levels. In addition, there is the higher performance of the fasteners in the hardwood. The specialist hardwood manufacturers, Neue Holzbau AG in Lungern – see the Ashes to Beech engineered hardwood piece here - supplied the primary supporting structure in ash with frames, some of which were assembled in the factory.
Imhof also decided in favor of ash because of its aesthetics, which he preferred to that of beech, which has similar strength values. In the cantina, the supporting structure creates a space - the supports are statics, architecture and interior work in one. That is why the way in which the wood is layered and glued was even discussed. When the supports are widened, dark glue joints stand out clearly from the light wood and show the typical properties of the material. “An honest approach”, thinks timber construction engineer Angehrn.
Ash can also be found in the furniture. Because the architects could not find any products that met their requirements – tables that were foldable, stackable chairs, as well as solid yet homely, Lukas Imhof and Carlos Wilkening, the project manager, set to to design a furniture series themselves. The furniture was designed to be able to be manufactured in-house, in supervised workshops within the Ekkharthof community, one reason for the technical and manual possibilities of the manufacturing process which had already been taken into account in the design: the number of individual parts is reduced, able to be high-precision CNC-prefabricated, with a simple series of work steps. Like the columns, the angular yet simple and robust furniture blends harmoniously into the room. Since then, Imhof and Wilkening, together with the Ekkharthof community, have set up a furniture making company, WIMMobel.
The wooden ceiling also contributes to this homely atmosphere. Behind the acoustic cladding, there are prefabricated, insulated ceiling elements which, in addition to the load-bearing rafters, also contain ventilation and various technology. The air ducts run in the roof turret - the fresh air is blown in above the windows and sucked out again at the ridge. Every connection, every light is carefully framed and detailed. You hardly notice any of the technology.
The architect Rex Raab built the Ekkharthof in the 1970s. In doing so, Raab oriented himself on what was known as the anthroposophical style with the second Goetheanum building in Dornach: eye-catching roof shapes, beveled angles - right angles are largely dispensed with - and different shades of color. Despite this concise context, the cantina blends harmoniously into the existing ensemble. Imhof referred to the original ideas of Rudolf Steiner, the founder of Anthroposophy, whose first Goetheanum was built in wood.
Notes
1 The buildings are grouped around the inner courtyard like a wagon castle. The new catering building encompasses the square to the south and at the same time closes the courtyard to the surrounding agricultural zone
2 The glass front, framed by massive wooden pillars, leaves the view of the rural surroundings unobstructed
3 The structure is reminiscent of a Vierendeel system. It is built in a self-bracing manner, without walls. The nodes are decisive for the moment load.
4 In the design, the architect Lukas Imhof referred to the Goetheanum in Dornach. Beveled corners and trapezoidal pier heads are characteristic of the building.
This piece first appeared in Holzbau Schweiz's First magazine
