Skysail is designed to be a great hybrid streamlined tower.  Resembling a great hoisted sail that channels solar and wind energy, it is an energy-saving green tower that subtly adds to the skyline of La Défense by diagonally occupying the site. Thanks to its subtle footprint it frees up ground space at the base of the tower and favours the relationship with the public spaces in the area.

The tower is 350m high, at its base the tower is pierced with a golden arch that is formed by inverted terracing, a large 50m cantilever jutting out towards the centre of the business district.  A long restaurant-terrace overlooks this void.

It has a complex geometry combining verticals and curves and in profile looks like a huge staircase. The ridge is composed of a series of enclosed green terasses which capture the wind; the air is then distributed into false ceilings. This natural ventilation is accompanied by aeration through the dual-skin façade.

The office spaces are flexible and amply lit by natural light thanks to large glass strips which are protected by a slatted sunscreen system. The structure is a concrete-metal hybrid (reinforced concrete central core and mixed flooring). The load-bearing façades are composed of a mesh of steel posts that slope slightly, therefore following the curvature of the building.

The tower requires little energy. All the sun-facing façades are equipped with photovoltaic captors printed on the floor bands. The tower is lit up at night thanks to this harnessed energy.