Two large feature were needed for The Edge building in Amsterdam, which upon completion received the highest BREEAM rating ever recorded by the Building Research Establishment, the global assessor of sustainable buildings.

The most prominent feature of the building’s atrium is a vast staircase, which gets narrower as it is climbed. Nine metres wide at the base and over four metres wide at its peak, the staircase weighs 24 tonnes and required specialist construction. The width of the staircase meant that each oak tread had to be reinforced with steel.

The second staircase is a freestanding structure that is constructed from matching oak treads, LED lighting and glass balustrades. Ending in a cantilevered terraced platform the staircase provides a space for speakers to address large groups of people in the heart of the building.