For their new premises at the existing company site outside Probstzella, the proprietors insisted on a timber construction. "Our client is very climate-aware. That is why we designed a zero-energy building where the heat dissipated by the production machinery is recovered for heating purposes," explains architect Martin Kopp from F64 Architekten. The photovoltaic plants installed on the roof of the building and in adjacent outdoor areas complement the carbon-neutral plant. For cooling, it is equipped with a geothermal collector system.
Lots of glass on ground floor topped by slate-clad façade
The ground-floor offices, recreational rooms and adjacent production space are fronted by up to three metre high glass façades, divided by columns every five metres. The office and the production areas are separated from each other by a sound-proof glass wall. "The glass façade emphasises the client's commitment to transparency and teamwork and the idea of equality and inclusion at the workplace," says Martin Kopp.
Above the ground floor level, the building is clad in slate, the region's traditional building material. The individual façade sections are tilted vertically at a range of different angles. "The angle changes the way the sunlight hits the building shell and the play of light and shadow produces interesting relief effects," says Martin Kopp. The building thus mimics a rock, reminiscent of the quarries in the nearby Thuringian Slate Mountains. The narrow triangles between the vertical and inclined façade elements are clad in silver-coloured sheet metal.
Transparent construction thanks to slender beech lattice girders
Slate is also found inside the building where the office area features a natural stone floor. In the production hall, a black industrial floor has been installed. Its dark colour is in contrast to the filigree lattice girder construction that appears to be floating above the ground and whose top chords are recessed into the hall ceiling. "We aimed at transparency and the impression of open space throughout the entire building," reports architect Martin Kopp. The production hall had of course to be high enough for the large machinery and rack systems of elobau. The elegant trusses spanning the 25-metre wide hall consist of slender BauBuche elements. "By using BauBuche, we were able to reduce the dimensions of load-bearing elements, achieving a more elegant look," explains Konrad Merz, who introduced the architects to the material from Pollmeier and proposed the type of construction. "BauBuche is simply the ideal material when it comes to modern lattice girder structures."
Dowel connections at truss nodes
A special feature of the lattice girder construction of the elobau hall are the truss nodes fitted with slotted metal plates and self-tapping dowel connections where the steel part is completely embedded in the timber. This joining method caters for high-precision connections between the top and bottom chords by uprights and diagonal elements. Konrad Merz describes the construction method: "Slits are produced in the timber into which the metal elements are placed before the dowels are screwed in." "The dowels are equipped with a self-drilling tip and come with a head that fits the screwing tool". They can thus be screwed into the timber and through the metal plates in one go. "The main advantage of this connection technique is its precision. Alternative methods with pre-drilling would be much more cumbersome and never as neat," explains Konrad Merz. "The method chosen for this building also saves time and thus money."
The posts and the wind bracing diagonals of the main support construction are also made in BauBuche. The ceiling and upper wall elements at ground floor level consist of triple layer boards with a white varnish finish suspended between the BauBuche posts and girders. These elements form an attractive contrast to the natural warm hue of the beech timber of the lattice girder construction. The south-west wall of the hall consists of a full-height glass façade for an uninterrupted view of the surrounding mountains.