A groundbreaking ceremony was held today to mark the beginning of construction on Foster and Partners twin towers in the Vivaldi urban quarter of Amsterdam. The 87m-high 24-storey tower was commissioned by ING Real Estate in 2002 - with Ernst &Young as the principal tenants. It is one of several office buildings located at the eastern gateway to the mixed-use Zuidas development, south of Amsterdam. The towers rise above the elevated motorway to the north, and are linked to each other by a transparent core that accommodates shared service functions. The appearance of the building is determined by a distinctive 'diagrid' that ensures the tower is readily-identifiable on the drive into Amsterdam.
The structural steel diagrid is clad in silver aluminium and offset against the dark glazed cladding panels, which reduce the definition of the individual floor levels. This creates an elegant and arresting lattice that scales the entire facade. Set back from the street, the towers are approached along a south-facing water-court under an overhanging canopy, which defines the relationship between public and private. The social and communal functions, such as staff restaurant, 'living room,' and entrance hall, are clustered around this water-court, and the canopy - when joined to those of the adjacent developments - will provide sheltered access to nearby transport links.
The office accommodation is divided into two 12.6m-wide column free blocks with equal floor plates of 600m2 each, allowing for multi-tenant occupation if required. The blocks are staggered in plan to admit as much natural light as possible and to make the most of the northerly city views. The central circulation core incorporates six lifts, escape stairs and toilet facilities. On the upper levels, the lift lobbies open onto double-height meeting spaces that are located between the two office wings. With the insertion of stairs between connecting floors, these spaces can serve four separate office floorplates by enabling horizontal and vertical connections. Executive facilities are located on the uppermost floors, and car-parking for 240 vehicles is provided underground. Access for all service traffic is at the rear of the building, via a dedicated service route that will ultimately connect all the towers on the Vivaldi site.
The scheme includes a series of environmentally progressive measures and is 10% more energy efficient than current Dutch requirements requires. Local legislation also stipulates that a large percentage of rainwater must be retained on site, before being released to the surface drainage system of this polder area. To achieve this goal, the lower plinth buildings have green roofs and the courtyard pond acts as buffer storage, with a biological filter of self-cleaning water plants. Any additional rainwater is directed into the building's service water.
The project is scheduled for completion in March 2007.