New Town Hall Oy-Mittelberg
Identity
The design task poses the fundamental question of how to deal with the village structure of Oy-Mittelberg and the associated surroundings. The new town hall is meant to form a symbiosis with the existing structure and closes the urban space towards St.-Anna-Square. The result is a building that continues the structural form of the site and implements functional necessities. The orientation towards traditional construction methods, the associated choice of materials and optimization of the building services contribute to a contemporary administrative building, which considers the issue of sustainability over the entire life cycle of the building from production, through use, to deconstruction.
Urban concept
A clear basic volume with an appropriate front area, gabled to the St.- Anna-Square, fits itself into the built environment. The gable roof forms a horizontal termination. The street space of Haager Street widens to the west opening up the public parking lot on the back side of the building. The topography along the main street is taken up by the outdoor facilities. An underground parking garage is embedded in the terrain.
Architectural concept and functionality
The form develops from a combination of the given: the program with its functional references and the identity derived from the surroundings. The building, which is uniformly clad from the roof surface to the base of the building, forms a homogeneous structure, which is intended to reflect the identity of the village community. The main entrance is oriented towards St. Anna Square. IT is set back, open and inviting. It provides weather protection and articulates a transparent relationship with the outside space and the villages citizens. The ground floor accommodates all civic functions in addition to a foyer. The main linear staircase provides access to the up- per floors and establishes a direct relationship to the other administrative spaces. The meeting room on the top floor opens a wide view across the close public space to the wide alpine panorama.
The design of the new building should neither form a modern contrast within the village center nor pretend that is has already been there for generations. New and yet in such a way that the question in which time the house was built is uninteresting. In other words, a house for the second glance, in captivating craftsmanship, with familiar materials, beautiful joints and a clear spatial concept that invites you to linger.
Construction and materiality
The load-bearing structure of the buildings ground floor and first upper floor is executed as a solid structure with reinforced concrete. This base- ment protects the wooden structure of the attic from rising damp. Glulam beams are used for the large spans of the roof structure. The roof truss as well as the interior and exterior walls are erected as a wooden structure. The façade appearance of the simple and compact house is determined by the clear structure of vertically arranged, rear-ventilated timber cladding.
The amount of window openings is limited to a necessary measure. The roofing was executed as a coated aluminum standing seam sheet roof.
The wall surfaces of the corridor partitions are boarded with silver fir boards. The interplay of the white office partitions and acoustic ceilings with the natural, light wood creates unagitated interior spaces with a pleasant atmosphere. The floor coverings of the public areas on the ground floor are designed as polished screed surfaces with additional aggregate of regional natural stones. Otherwise, parquet flooring is used.
As a matter of principle, great importance was attached to the use of durable, biologically harmless and ecologically sensible materials for the whole building structure. All material decisions were made with a view to their life cycle and coordinated between the client and planners in an interdisciplinary manner.
Energy and sustainability concept
The building structure has an optimized envelope surface, which results in low heat losses. The quality of the individual components complies with current energy-standard values, which means that the building is oriented towards the standard of low-energy construction.
The design is based on traditional construction methods in order to achieve an optimum level of comfort with the lowest possible use of building ser- vices, which is comprehensible to the users. This reduces the ecological footprint already during the construction of the building, which is also optimized in the utilization phase through lower energy consumption and reduced maintenance and repair work. In the event of deconstruction, all materials can be separated by type and reused. The wooden walls and the roof truss contribute to the compensation of the CO2 emissions of the concrete base required for the construction in the alpine terrain.
Heat is supplied by connection to the local district-heating pipeline. Within the building, heat is distributed via underfloor heating, which can be up- graded to cooling as well. Passive cooling is provided by means of mechanically controlled night ventilation, which uses the building's thermal storage capacity and activates it by increasing air exchange during the cool night hours. As an additional measure, it is possible to retrofit a heat exchanger for active cooling. The low percentage of window area prevents overheat- ing and avoids more costly cooling measures. For reasons of room hygiene, a ventilation system with heat recovery and time program was implemented to optimize consumption. In addition, all rooms have constantly set air volumes depending on use. A photovoltaic system generates the en- ergy for the building's technical installations; the system of the existing city hall was integrated.
In order to achieve an energy-optimized concept, engineers and architects worked together in an interdisciplinary manner from the very beginning. All planning was carried out on an open product basis in order to achieve the best possible CO2 balance during production, operation and later decon- struction. The architectural design of the building and, above all, the deci- sion for a contemporary transfer of traditional building elements from the Allgäu foothills of the Alps were intensively discussed. We as architects benefited greatly from this discourse. As a result, the design has been sharpened throughout all phases of planning as well as execution and has led to a result that is consistent for us.
