Ecological timber hybrid construction

CANZLER has built a new administration building with an area of around 10,000 square metres plus an underground car park in timber construction for the growing district administration of Mainz-Bingen. The offices in the four-storey building in Ingelheim, Konrad-Adenauer-Straße 34, have now been occupied by the majority of the approximately 250 employees. With this sustainable building, the district administration wants to set a visible example for climate protection.

 

The design planning of the administration building in timber hybrid construction was based on a plan in conventional construction, which the district administration had designed itself in advance. CANZLER was then entrusted with the approval and implementation planning, as well as the tendering, awarding and site supervision. Sustainability was the focus of the overall concept from development and construction to use. Ecological and natural materials predominate both inside and out. The building was planned with an eye to the future so that it could be expanded if necessary.

 

"The aim of our planning was to leave the wood visible throughout the building and thus make it tangible," says Aleksandra Seifert, CANZLER's architect in charge. This becomes visible in the light-flooded foyer, which extends over two floors in the middle finger of the building. As a place of arrival, it conveys a natural impression through its organic design language and the glulam (glued laminated timber) supports made of birch, which were approved for the first time in Germany. "The skeleton construction method allowed us a very high degree of design freedom in the process."

 

High flexibility - natural materials

The first floor of the two-storey foyer houses meeting rooms, the ground floor the reception with telephone exchange and offices as well as the canteen with the adjoining seating area in the inner courtyard. The upper floors, on the other hand, are reserved for office use. In the outer zones there are individual, group and 124 standard offices with two workstations as well as larger meeting rooms. The grid of 1.35 and 2.70 metres provides the necessary flexibility. The standard office is located exactly between two support grids: BSH columns and beams made of birch form the frame. Below the windows, a paneled window sill serves as a shelf and for sitting. White plasterboard walls contrast with visible spruce BSP ceilings. So-called silent rooms for meetings are located in the central zone, separated by glass walls, as are service rooms, e.g. kitchenettes, mail distribution rooms or archive rooms. Cooling and heating is provided by radiant ceiling panels with integrated lighting. In the interplay of natural materials and earth tones, the exposed concrete on walls and ceilings in the stairwells stands out.

 

Construction according to the Lego principle
While the basement with underground car park was built in reinforced concrete, the floors above continue in timber construction. The structure was braced by three concrete cores with stairs and lift as well as load-bearing walls that form the fire compartments. The core consists of a modular timber construction made of prefabricated timber elements that were placed on top of each other floor by floor on the construction site - comparable to Lego building blocks. What sounds simple was a challenging task, explains Seifert: "With the size of the building, the materials and constructions of wood, steel and concrete used, and thus different processes, it was necessary to plan the execution down to the last detail. We drew up the construction schedule at a very early stage during the execution planning/tendering process to ensure deadlines and completion."

 

First, the façade of 400 prefabricated wooden façade elements with windows and sun protection was put together, starting on the ground floor. Construction was carried out in 16 sections, which resulted in rapid progress. After the building envelope was closed, the interior was finished from top to bottom. The energy efficiency of the building is reflected in the KfW 55 subsidy; it received a subsidy from the Landesbeirat Holz for its modular timber construction system.

"With this new building, the Mainz-Bingen district administration is setting an example in terms of sustainability and climate protection. By using wood as the main building material, we are making a valuable contribution to reducing the CO2 footprint and ensuring excellent energy efficiency. For SOCOTEC Germany, this successful project is an example of how we use our expertise to develop solutions for a sustainable future together with our customers," explains Ludger Speier, CEO SOCOTEC Germany.