Transformation of School Davos
The school complex in Davos Platz is converting its operations to a day structure and requires additional space for the assembly hall, cafeteria, administration and additional classrooms. The existing building from the 1960s was therefore to be demolished in favor of a new "ecological" building. In order to preserve the stored grey energy, an integrative solution with the existing building was proposed instead, in which the old structure is extended on the long sides and a storey is added to meet the growing requirements of the program.
The new building therefore is placed over the entire existing structure and completely encloses it with a new shell, which both meets the thermal requirements and pursues a new aesthetic standard. From the outside this hybrid appears to be a new building, while actually 40% of its volume consists of the existing structure.
The extensions are constructed from an efficient timber grid, which is based on the wall axes of the existing building. The third floor, which has been added on top of the existing roof, is carried off via the lateral extensions, which means that no additional load is placed on the existing structure.
While the public first floor is oriented towards the covered schoolyard, the classrooms and offices on the upper floors are arranged around a central communicative atrium. Together with the versatile corridor areas, this offers a variety of individual learning and retreat options, which enrich the traditional school operations in many different ways. The new part facing "Schulstrasse" is connected to the existing staircase landings, which means that the new and old buildings are each offset by a half storey. The extension towards the schoolyard allows to shift the classrooms away from the cores, resulting central circular route inside the building, where you can playfully switch between the existing and new building on each mezzanine floor.
Sustainability Concept
While a quarter of all CO2 emissions currently come from the building sector, every new building is faced with the task of ensuring resource-saving construction and energy-saving operation. Although the existing school building from the 1960s was no longer functional or structurally viable, it was well positioned in terms of urban planning and had a solid and flexible structure. It was therefore a matter of course to retain the existing building components and use them to design a concept for an extension.
This meant that almost 40% of the load-bearing structure in the new building and the staircases could be saved, which has a significant impact on resource consumption and CO2 emissions.
All new extensions were built in timber, which means that the building functions as a long-term CO2 store. As the solid existing structure has sufficient thermal mass, efficient heat storage in the new lightweight construction is unproblematic.
For all newly constructed parts of the building, the focus was on using regional and renewable building materials. The open timber structure, the massive wood ceilings with sheep's wool acoustics and the cork floorings create a cozy atmosphere and form a counterpart to the massive concrete structures of the existing building. Therefore a conscious distinction was made between old and new components so that the conversion process remains visible to the students.
The integral low-tech concept makes it possible to avoid controlled ventilation. All learning and working areas can be cross-ventilated by opening both the windows to the outside and to the central atrium. This nine-meter-high room can be opened up to the roof garden and acts as a kind of natural chimney. The building's own energy requirements are covered by a geothermal system and PV modules.
