Timber Hat
Architect: rundzwei Architekten BDA
Location: Rottenburg-Ergenzingen, Germany
Type: Headquarters, Operating Facility
Year: 2023
Photographs: Gui Rebelo | Estúdio Elefante
The following description is courtesy of the architects. In an ordinary industrial park south of Stuttgart, rundzwei Architekten BDA have designed an unusual headquarters and operating facility in timber construction. The translucent, all-round canopy made of carbonized larch wood – the eponymous “wooden hat” – protects against the weather and gives the building its characteristic shape.
“When a long-established family business builds anew, things don’t always have to stay the same” says Architect Marc Dufour-Feronce.
Hald & Grunewald specializes in the sale and rental of forklifts, telescopic handlers, work platforms and container solutions. Training, maintenance and repairs are also part of the offer. Around 90 employees work at the new main location in Ergenzingen, between Schönbuch, the northern Black Forest and the Swabian Alb.
The aim of the project was to bundle all the company’s functions at one location. At the beginning of the project, the architects analyzed and optimized the existing workflows together with the employees. The aim was to “rethink” the long-established family business, to question old structures and to create a contemporary commercial building with optimal workflows and quality of space for all user groups.
One place to work for all
Hald & Grunewald’s new building consists of two elements: a 10-meter-high hall section (factory building) and a three-story office section for administration (operations building). Both building parts are directly connected to each other and together form a flat cuboid. Of its floor area, the three-story operations building accounts for about one quarter and the plant building for three quarters. The third floor of the office section is cantilevered on both sides by 6m over the lower volume. A circumferential, hood-like canopy connects the main body and the crossbar to form a structural unit.
The construction and supporting structure of the entire building follow the motto „as much wood as possible”. The hall of the plant building consists of cantilevered glulam beams supported on glulam columns. The hall façade is also of timber construction. A surrounding exposed concrete base protects it from mechanical damage. A fire wall made of in-situ concrete separates the hall section from the operations building, which extends from here to a facade made of precast concrete columns and timber frame elements. The floor slabs consist of cross laminated timber (CLT) slabs, supported on glulam beams. Only the area above the atrium was designed as an in-situ concrete floor. In its oval open center, a representative steel staircase swings up from the first floor.
This spiral staircase connects the three office floors and provides direct lines of sight into the offices, training rooms and communal areas such as the café for employees. Generous window fronts let natural light into the building and create an open, communicative working atmosphere. The transparent design of the interiors, e.g. through glass partition walls between the offices and light acoustic ceilings made of wood, promotes communication and cooperation between the employees.
Sabine Marquardt, Managing Director of Hald & Grunewald, reports: “They are proud to be able to work here – and are much more open with each other. In addition, the new “corporate architecture” of the family-owned company also assists in recruiting personnel: “We have received unsolicited applications – simply because of the location and the building.“
Canopy and facade: carbonized larch wood protects untreated larch wood
The full perimeter canopy stands out from the rest of the building in terms of design, while at the same time connecting the main body and the crossbar. The canopy cantilevers six meters and then tilts vertically. This simple but effective design not only provides protection from direct sunlight and rain, but also contributes to structural thermal insulation. Around the building, the canopy creates protected circulation areas and workspaces, as well as parking areas for picking up and dropping off rental vehicles. At the same time, the translucency of the canopy ensures natural lighting of the hall areas in the area of the factory building as well as the offices of the company building.
In the choice of materials for the new company headquarters, the client’s wish to make the ecological construction method visible was paramount. The façade also had to be durable and low-maintenance. To this end, rundzwei Architekten combined two different types of larch wood: the vertical surfaces of the canopy consist of orthogonally screwed wooden lamellas. They were charred – i.e. carbonized – by hand according to the Japanese tradition of yakisugi, thus protecting them from the weather. Wood treated in this way absorbs less water and is protected from mold, weathering, rot and water. In contrast, the wooden façade of the actual building structure is made of light-colored, natural larch wood. Due to the wide overhang and the height of the canopy, these untreated facade surfaces are protected from weathering.
Cost-effective heat supply and recreation on the roof
Sustainability and energy efficiency also play an important role in the building services of this commercial building. A combined heat and power unit supplies the underfloor heating in the factory building and the office section with cost-effective heat; it also covers a large part of the electricity requirements of the building, which is insulated to low-energy standards.
In summer, the absorption chiller ensures a pleasantly cool climate in the rooms. A large part of the roof area was planted as an extensive green roof, which serves as a habitat for birds and insects and is available to employees for recreation on the adjacent roof terrace. Fresh air is supplied via windows that can be opened manually. In addition, the moisture-absorbing wooden surfaces of the structure contribute to the natural air conditioning of the room air.
Project Details
- Name: Timber hat
- Location: Rottenburg-Ergenzingen, Germany
- Client: Hald & Grunewald GmbH
- Architecture: rundzwei Architekten BDA
- Project team: Paolo Bradicic, Marc Dufour-Feronce, Sunghoon Go, Asya Güney, Deborah Matter, Marie Nägele, Hannah Reckenthäler, Andreas Reeg, Shadi Zaghloul
- Project management: Ulrich Franke GmbH, Bau Consulting + Control, Berlin
- MEP engineering: Janowski Ingenieure, Berlin
- Fire protection consultant: brandschutz plus, Berlin
- Building physics: ELB Energieberater im Land Brandenburg, Potsdam
- Structural engineering: knippershelbig, Stuttgart
- General contractor: Brüninghoff GROUP, Heiden
- Heating and plumbing: Gühring Heiz- und Sanitärtechnik, Rottenburg
- Electrical systems: elektro breitling, Holzgerlingen
- Painting work: Heinrich Schmid
- Photographer: Gui Rebelo / Estúdio Elefante
