The Building At the beginning of May 2009, Boele & van Eesteren started work on the construction of TNT's new head office in Hoofddorp. The office building has a semi-submerged parking garage with six office floors above that. The atrium is very prominent and the steps it provides are designed to entice people to take the stairs. The façade at ground level is an aluminium curtain wall, while an aluminium window frame strip and an aluminium parapet element close off the façade on the upper floors. What at first glance appears to be an ordinary office building turns out to conceal a number of surprising elements. For example, once ready the building is expected to be the top sustainable building in the Netherlands. To achieve this, the building will have to earn two certificates, one of which has never been used as the basis for constructing a building in the Netherlands.
GreenCalc First of all, the building will have an Environmental Index of at least 1,000 points in accordance with the GreenCalc methodology. This is more than 1.5 times better than the current building with the highest Building Environmental Index. This index is determined on the basis of the materials and the quantities used. During the design and preparation for the construction of the building continuous attention is devoted to assessing whether the choice of materials is the most environmentally friendly and whether the quantities remain within estimates so as to guarantee that the building achieves an ultimate index of at least 1,000. Not only materials count towards this goal. How water and energy are treated also contribute to a higher index. The TNT Green Office will have a bio-CHP (heat-power coupling to biofuel) for the purpose of generating power. As a result, the building will require little to no power from external sources.
LEED is an American methodology for assessing the sustainability qualities of a building. The assessment takes place in the area of design, implementation, the ultimate use and management. This is tracked in five categories: materials, energy consumption, efficient water use, interior environment and the environment. By way of example: the location is important, therefore including the proximity of the building to the public transportation network. But the methodology also extends to the need for documenting the specific properties of the paints used. These may not contain larger quantities of harmful substances than those prescribed by LEED. In addition, a prescribed minimum quantity of recycled materials must be used and a large percentage of the materials used must be ‘regional'. That means, extracted and processed within a radius of 800 km from Hoofddorp. Credit points can be earned within the five categories listed above. The higher the number of points earned, the higher the score. The highest certificate that can be issued under this methodology is the LEED Platinum Certificate and this will indeed be the certificate awarded to the building once it is complete.