Foster + Partners has completed a headquarters building for Ernst &Young at the gateway to the Vivaldi-park area of the new Zuidasdistrict, south of Amsterdam. Commissioned by ING, the towerestablishes a landmark on the route into the city with its diagridfaçade. Ten per cent more efficient than the target Dutch environmentalstandards, the building also extends the public realm with a watercourt at its base.

The 24-storey building is divided into two twelve metre-wide columnfree towers with open, flexible floor plates. The blocks are staggeredin plan to admit as much natural light as possible and to make the mostof the northerly city views. The northern façade is fully glazed, whilepartial thirty per cent glazing to the east, west and south limitssolar gain. Combined with ground water storage to further save onenergy for cooling, the overall environmental strategy is highlyefficient.

Linked by a shared transparent core, the offices are serviced bydouble-height meeting spaces and light-filled social spaces allowingcommunication between different floors. The structural steel diagrid isclad in silver aluminium and is offset by opaque black panels, whichreduce the definition of the individual floor levels. This latticescales the entire 87-metre high facade and gives the building itsidentity. At the base of the building the height of the diagrid createsa triple-storey lobby space, while at the top of each tower north andsouth-facing terraces are set into the structure.

The towers are approached via a water-court with an ecological pondbeneath an overhanging canopy. Defining the relationship between publicand private, this space houses the social functions, such as staffrestaurant, terrace, auditorium and bar, clustered around thewater-court. Coupled with a green roof on the restaurant building, thepond has an important environmental contribution. 65 per cent ofrainwater is retained on site while the run-off feeds into theAmsterdam canal system to control water levels following peak rainfall.The pond is naturally cleansed by a planted biotope of reeds, waterlilies and grasses.

David Nelson, Senior Executive and joint Head of Design at Foster + Partners said:
“Our first building in Amsterdam not only exceeds Dutch environmentalregulations by ten per cent, but provides a striking marker for theVivaldi park area, a high quality, flexible working environment fortenants Ernst & Young and a lively public water-court with aworking ecological pond at its base.”
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