Residential neighbourhood in Preddvor, Slovenia

Multi-storey multi-dwelling in timber construction represents a new milestone in construction technology. It involves many additional challenges that are almost negligible in terms of complexity in prefabricated individual construction. In addition to the proverbially more problematic seismic construction in Slovenia, which requires a very different approach for lightweight timber structures than for solid ones, achieving adequate fire safety is proving to be the most pressing problem. Unlike other types of buildings, such as kindergartens, office buildings or secondary schools, where the whole building is used by the same occupant, in the case of flats it is necessary to ensure that all the flats are separated from each other by fire.

In conventional solid construction, the risk of fire spreading upwards through the façade or interior of the building is manageable, mainly due to the non-combustible materials. The same technique is in principle also applicable to timber construction, whereby all timber surfaces, both on the façade and on the interior of the building, must be covered with non-combustible materials. In reality, the choice of material is reduced from its symbolic role to a purely utilitarian one. The timber structure “disappears”, the real structure of the building is completely obscured.

In the design of the competition project for the northern edge of the larger residential neighbourhood that will be built in the next few years on the site of the Jelovica factory in Preddvor, we have made every effort to design a wooden multi-apartment building where its organic and low-carbon structure is revealed both externally, i.e. on the façade, and in the interior of the apartments and the common communications. Based on the default layout plan, which specifies the layout and dimensions of the three blocks of flats, the selected programme was divided into three characteristic layers. The ground floor is mainly public amenities, retail and catering outlets, health services for the wider local community, a kindergarten and a few apartments with their own small garden. On the next two to three floors, there are mixed-structure dwellings, mostly smaller and medium-sized. Under the undulating roof contour, we have placed several larger apartments. This has resulted in a predominantly public and pedestrian character of the ground floor and the external layout. Most of the parking spaces are located in the underground garage.

When choosing materials and construction technologies, we follow the principle of using materials that are as simple as possible, whether inorganic or purely natural. We avoid synthetic and composite materials that are difficult to reuse or recycle. The ground floor is constructed with thermal insulating bricks, while the floors above are timber-framed in combination with cross-laminated panels. A structural and artistic peculiarity is the terrace floor, where the structural logic is reversed. The façade becomes load-bearing in a dense rhythm of doubled supports following the structure of the timber roof truss. The fully glazed façade is set back in depth and thus suitably shaded. The entire roof is glazed and visually separated from the more “massive” base. The character of the building is also defined by the uniform structural rhythm, which continues down the façade as a wooden ‘curtain wall’ of blinds, railings and technical mesh.

Given that the zoning plan predetermined the final dimensions of the individual buildings, located at an extremely exposed entry point to the Preddvor settlement, we have also paid a lot of attention to their relationship to the current surrounding and also traditional architecture. The design of the undulating roofline adapts to the varied scales of the environment, while the uniform rhythm and articulation of the façade follow the logic of the larger commercial buildings in the Slovenian countryside. It is defined primarily by a simple, repetitive and clearly legible structure. The synthesis of the programme, i.e. the individual and varied dwellings and the much more unified envelope, is a dynamic balance between the individual, the collective and the contextual.

Authors: BLENKUŠ Matej; CIMPERMAN Katja; VALENČIČ Grega; KLOBČAR David; GAZVODA Matevž