A new administrative centre
Until a short time ago, the public services for the 30,000 inhabitants of Houthalen-Helchteren, a town located about 15 kilometres north of Hasselt in Belgium’s Limburg region, were scattered across numerous different buildings, many of which were obsolete or unfit for their purpose. Hence the desire to build the New Administrative Centre (NAC) and to make it an example of innovative architecture in terms of aesthetic appeal and efficiency and sustainability. With its blue tower and roof garden, the building is a striking presence and serves as a local landmark. But most importantly it brings together the various municipal services under one roof – including social services, public library and police station – making life much easier for the town’s inhabitants. The ambitious brief given to the architects by the mayor was to create a totally eco-friendly urban landmark which would be able to cut energy costs with a view to recovering a portion of the investments in the long-term period. Following a public call for tenders, in 2010 the administration decided that the project proposed by Mandala Consortium, led by the Hasselt-based practice Holistic Architecture 50│5, was the one that best met the design brief. The project consists of a building with an organic, sinuous shape, reminiscent of a ship with its funnel gradually integrating into the surrounding urban landscape. Distributed over a surface area of 17,000 square metres, the NAC eventually proved to be one of the most sustainable public buildings in Belgium. The bold design reconciles energy efficiency with the maximum functionality for both staff and the public. The plasticity of the geometric shapes adapts intelligently to the naturally undulating surface of the site. The project has achieved efficiency by incorporating the various functions into a single architectural unit in keeping with the principles of the Cleantech Campus, a clean energy building with the long-term aim of reducing CO2 emissions by 90 percent.
The dominant characteristics of the building are its blue tower and the green roof conceived as a kind of roof garden. In reality, the benefits of using earth, plant fibres and turf or moss to insulate dwellings were well known to populations living in colder and more humid climates across Europe, from the Venetian Lagoon to Germany, the lowlands of Belgium and Holland, and Finland. The tower itself, consisting of 5 elliptical rings with a height of 19 metres and diameter of 22 metres, represented both a technological challenge and a landmark. Its shape is inspired by the large cooling chimneys of the coal mines and electric power stations that until 30 years ago were the main resource of the region. Standing guard over the main entrance to the building, the tower clad with small blue tiles also marks the union of earth and sky, a line that in the lowlands of Belgium and Holland is often rather hazy. The municipality’s inhabitants will have easy access to all services from the spacious central atrium tiled with Ecotech collection porcelain tiles from Floor Gres with high recycled content.
The NAC is now a benchmark for all aspects of energy saving and sustainability. It has 35 cm thick insulating walls, triple glazed windows with blinds, rainwater collection and reusable water separation systems, detectors in all spaces to save on power for lighting, and a heating and ventilation system integrated into the concrete supporting structure, which heats or cools the spaces through the ceiling. Everything is designed to achieve savings in running costs and to optimise the public investment over time. And if this is something worth celebrating, the NAC itself is the perfect place to hold a party as it is equipped with spaces for ceremonies, parties and catering facilities. So by hiring out the building for events, the municipality can make earnings and not just savings.
Floor Gres, Ecotech series
Water absorpion (ISO 10545-3): E ≤ 0,1%
Chemical resistance (ISO 10545-13): UA ULA UHA
Resistance to deep abrasion (ISO 10545-6): <150 mm3
Stain resistance (ISO 10545-14): conforme
Frost resistance (ISO 10545-12): conforme
Modulus of rupture and breaking strength (ISO 10545-4): >40 N/mm2
Slip resistance (DIN 51130): R10
Thermal shock resistance (ISO 10545-9): conforme
Crazing resistance (ISO 10545-11): conforme
Linear thermal expansion (ISO 10545-8): conforme