Architectural practice Foster + Partners has confirmed that the Hermitage Plaza mixed-use development for La Défense in Paris will open by the end of 2014.

Designed by Foster + Partners, the twin tower buildings of Hermitage Plaza will take the form of interlocking triangles which face one another and enclose a large public piazza.

As the towers rise, they will turn outwards to offer sweeping views across the city from large feature windows.

Covering a total site area of 161,458sq ft (15,000sq m), the first tower will have 91 floors and the second will have 92.There will be 538 apartments, as well as the panoramic spa, a hotel and offices.

Design features will include glazed façade panels with different points catching the light throughout the day as the sun moves.

The building will be braced by a diagrid structure and incorporates a number of sustainable features. These include angled façade panels, which will promote self-shading, and vents which can be opened to draw fresh air inside. Work is scheduled to begin in 2010.