Tunnel construction rapidly raises the height of a high-rise tower

Seven days per floor on a narrow lot

Seventeen stories of tunnel construction in 160 days, and for the tower, the repeating top eleven stories were built at a rate of one story per seven days. This is how Casco Bouw Nederland constructed the concrete shell of the De Oosterlingen high-rise tower in Amsterdam. It was the first collaboration with general contractor Vink Bouw, on a lot where space was extremely limited.

Casco Bouw was responsible for the tunnel construction of blocks 6 and 7—the highest part of the project. This was followed by the lower-lying blocks 1 and 2, where Casco Bouw Nederland constructed the concrete walls and wide-slab floors. For Vink Bouw, this was the first time the entire concrete work—including concrete, rebar, and formwork—had been subcontracted. “That worked out very well for both parties,” said Director Jan Hokse. “A great collaboration between down-to-earth companies with the same culture. That’s when you know the project is bound to go well.”

Cramped construction site

The biggest challenge was space. “It’s all very cramped in downtown Amsterdam. That requires a lot of organization, mutual consultation, and cooperation,” said Hokse. Speed remained the guiding principle throughout the project. “We completed the repetitive floor levels of the tower at a rate of one floor per seven days.”