In Vienna, near the Westbahnhof, at the highest point of Felberstraße, a two-storey rooftop extension has been added to a late nineteenth-century house. In a fully built-up area where it it is hard to find any additional residential volume, the architects Regina M. Lettner and Günter Lagler of skywood by baukult set a new two-storey space on top of the existing building. The rooftop extension, called ‘Bird of Paradise’, is an example of excellence in urban densification, in terms of cost-effectiveness, ecology and adding value to the property. Lightweight and quick construction is often the key to success with extension projects, and this makes special demands on planning and materials. Here, the architect and owner skilfully used the light and high-performance materials wood and steel, which gave her the most freedom with the design while respecting the existing structure. The extension is made mainly of prefabricated wooden elements with some steel. The structure is exposed and visible in the interior, making an architectural statement. The wide-span Kielsteg elements form the roof structure and set new standards for urban wooden building by reducing the load on the substructure and creating pillar-free floor plans. The roof is partly green and partly covered in photovoltaic panels. After only five weeks in construction, the new living space is inviting, spacious, open and full of light, with fantastic views into the far distance. Wherever the existing structures and the planning regulations allow, this type of rooftop extension in wooden construction offers the perspective of activating valuable and much-needed reserves of urban living space with a low CO2 profile.
The town of Ried im Innkreis is building a new centre for its public works department and decided to be ambitious about both the functional concept and the architecture. Urmann Radler architects from Linz won the competition to design a building as a headquarters for the street cleaning, maintenance and waste collection and the vehicle fleet. The new single-storey building stands between an industrial zone and a residential area on the southern edge of the town. The building with a floor area of 2270 m² gathers a number of public works activities in one place that were previously scattered across multiple locations. This creates a clear functional structure where people don’t have to go far between the offices, the different workshops and the garages. The new public works HQ occupies a sensitive site between the industrial and residential zones, resulted in a number of special aesthetic and functional requirements for the design. All of the activities that produce noise, the garages and their access ways face towards the industrial zone. The garage for cars is set into the slope of the hill along the edge of the site next to the residential district, which hides the facility from sight and also creates an acoustic barrier. The low-level garages enabled the creation of a green strip with bushes and trees that forms an additional natural boundary. All the vertical parts of the building are made of reinforced concrete, with a combination of solid walls and skeleton framing. To cover the large spans of the workshops, Kielsteg elements are used to create a visible roof structure. The advantage is the flexible use of the space, with the ability to respond to changes in the layout and equipment over the coming years. The facade is clad in vertical pre-greyed larch strips, underlining the unity of the building, with a quiet ambience at the transition between living and working areas.
The municipality of Fels am Wagram in Lower Austria has extended the buildings of its primary school and ‘Neue Mittelschule’ secondary school by adding a new sports hall. Besides providing the schools with a new gymnasium, the building also adds new spaces for afternoon supervision in the form of a foyer, a library, and a kitchen with serving area, and can also be made available to outside organizations for sports and other events. The sports hall was designed by Christian Galli architects from Krems, tender and building inspection was managed in cooperation by Atelier Langenlois Kerzan u. Vollkrann. The result oft concept have made the complex with the two schools into a very attractive central meeting place with clear functionality. The new space concept has a total usable floor area of 1,143.34 m² and incorporates an old vaulted basement, which was retained from the existing building. The flat roof of the 430 m² gymnasium is formed by cambered Kielsteg elements, 56 cm high, which cover the 15 m width of the building in one span. The choice of Kielsteg resulted in a significant reduction of total material use thanks to its unusually low height – achieving the required interior height with a lower total height of the building. Another advantage of Kielsteg is that by combining the load-bearing function with the roof skin in a single uniform layer, it allows attachment of sports equipment and ventilation systems at any point in the roof. The hall went into operation on time at the beginning of the 2019/20 school year.
Stylish and functional is a good description of the KIELSTEG roof of the EDEKA supermarket in Beckingen, in the Saarland region of Germany. In the building with a 1,500 m² floor plan, the Kielsteg elements span 26 metres and form a projecting roof over the entrance area another 6.5 metres deep. In this way the sales floor has a large area, uninterrupted by pillars, where the furniture can be arranged and rearranged flexibly. The prefabricated Kielsteg elements, which have an environmental product declaration (EPD) and therefore a transparent CO2 footprint, create a congenial ambience in the space with their natural, striped wooden surface. The effect is completed by the design of the lighting and utilities suspended from the ceiling. The supermarket opened in April.
With an eye to sustainability, the roof of the new EUROSPAR supermarket in Hartberg, Austria, was built using around 2,300 m2 of Kielsteg wooden construction elements. Other factors in the choice of Kielsteg were its elegant appearance, rapid construction and structural performance. The large clear spans result in a shop floor area of circa 1,700 m2, with the stylish natural wooden surface contributing to a smart but relaxing ambience. The flat roof, which is only half a metre high, is constructed so that half of its area can be green. For the building, which is 31.1 m wide with a 5.4 m projecting roof, only one central support axis is needed, with two pillars. The Kielsteg elements that form the front section with the projecting roof are 21.1 m long, and the elements that cover the rear section are 15.4 m long.
Kielsteg elements have proven themselves in a large number of projects across the EU and beyond especially as a way of creating large clear spans and achieving high flexibility of use of interior spaces in buildings. This was possible thanks to good cooperation with a sales network of competent local designers and builders, now with partners in six countries. To further strengthen Kielsteg in regional and international markets, it became important to obtain a European Technical Approval for the technology. Following almost three years of work with MPA Stuttgart as the testing centre managaing the process, the ETA has now been issued by DIBt Berlin. For us and our partners in Austria, Belgium, Switzerland, Germany, Italy, and Norway this is a step up to the next level. In the member states of the EU, the manufacturing and use of Kielsteg is now regulated by the European Technical Assessment which is the basis of the CE label.
Building with wood reduces CO2 emissions in two ways. Wood is a natural building material. To make it, trees need earth, water, air and sunlight, and as they grow they store CO2, which directly affects climate change. In the processing phase, wood needs much less energy input than bricks, concrete or steel. Building with wood is the most efficient method of avoiding CO2 emissions. Lightweight construction systems such as Kielsteg use up to 50% less material compared to solid materials. So Kielsteg should be understood as a contribution to the discussion about the future of sustainable use of wood. But if we make claims about sustainability, we should be able to back them up. So to support we have decided to voluntarily make the CO2 footprint of Kielsteg transparent for our customers over the whole life cycle of the elements. The accounting of the CO2 indicators was carried out by the IBO Austrian Institute for Healthy and Ecological Building and verified by Bau EPD. At the beginning of April, Kielsteg became the first holder of an EPD for wooden construction materials issued as part of the Austrian EPD programme listed and verified by Bau EPD. EPDs environmental product declarations), are internationally recognized and standardized instruments for certification of buildings. Environmental product declarations for building materials are not mandatory at the moment, but can make an important contribution to climate protection by promoting low-CO2 building. Our Kielsteg EPD is certified according to international and European standards ISO 14025 and EN 15805, and is therefore used by our sales partners in Europe and in other parts of the world as part of their approach to creating buildings with low CO2 footprints.
Our Scandinavian partner Control AS has completed a project using Kielsteg for the roof of a CO2-certified supermarket. The Kiwi supermarket chain, which has 650 stores in Norway, has opened a new shop in Skollenborg, a town about 90 km south-west of Oslo. The company has set itself the goal of operating as sustainably as possible: for this reason 70% of the products sold are from Norway and the building materials are CO2 certified. The Kiwi store won the architecture prize. The jury commended the clear architecture, the accessibility features for vision-impaired people and the easy-to-navigate organization of the shop, and highlighted the significantly reduced CO2 footprint of the whole project. The building is constructed to passive standard. The Kielsteg roof covers an area of 1300 m² and has clear spans of 23 m while remaining strong enough to withstand Scandinavian snow loads. The CO2 reductions were partly achieved by insisting on materials that were produced with lower-than-normal CO2 emissions – including the concrete, insulation material, steel and asphalt. Kiwi’s head of store development, Jan Eilif Johansen, says the prize shows that their design is well accepted by the market. The way this store was built applied new knowledge to achieve even better functional and environmental benefits. As the chain with the most stores in Norway, the company sees its role as setting an example of how to deal with people and the environment responsibly.
In Pirching near Gleisdorf a new complex of a building center in a very modern design is realized for Landring. For the shop building with 3,530 m² of floor area, the company has chosen a wooden roof structure for its sustainability, performance and aesthetics. A further important reason for the selection of Kielsteg elements was the flexible use of the building, which results from the outstanding structural performance of the wooden elements. The Kielsteg elements used aware as a visible roof structure which is resting on a classical concrete primary structure. This efficiency pays off handsomely.
The Styrian family business Faustmann has been producing furniture and interior fittings to the highest craft standards for 26 years. Their growing production operation in St. Johann near Hartberg, and 11 showrooms with expert customer service in Styria, Carinthia and Burgenland demonstrate the company’s determination to expand. Faustmann decided to build a new factory from scratch to increase capacity and also to improve competitiveness. The new 5,000 m² production space is designed to be as flexible as possible, so that it can be easily adapted to changing market demands. The structure is entirely made of wood and expresses the same clarity of form and material as the company’s furniture. It uses Kielsteg elements as a structural roof and also uses their aesthetic underside as a visible ceiling in the interior of the factory. Elements 16 m in length are being used in three spans across a frame of primary and secondary glulam beams and posts, with a span length of 5.25 m. The building uses a total of 3,569 m² of Kielsteg elements in visual surface quality.