3XN, a Danish architecture company based in Copenhagen, completed its first project in France, the InDéfense office and Hôtel OKKO situated side by side between the railroad and a road in the Les Groues neighbourhood of Nanterre, overlooking the La Défense business area.

The building had been erected with "different but complimentary" faceted checkerboard facades made of reflecting and bronze-coloured aluminium. The two buildings were created with a similar formal and material language and joined along one of their edges to make a longer piece of street front. This was done to produce a powerful visual emblem for the busy neighbourhood.

"As the first shape you encounter when arriving from La Défense, this building had to be eye-catching and dynamic. The faceted facade and shifting volumes make it a standout in the busy district. The concept – two distinct but complementary designs – is unique in the area," said 3XN founding partner Kim Herforth Nielsen.

A covered cut-out beneath the office building joins the front and back of the site where the two structures meet, and a dark spiral stairway rises up into the building. The office is more extended and divided into many block-like shapes that have been "pushed and tugged" to give a sensation of depth, and little terraces for the top floors, whilst the hotel is organised in an L-shaped form that twists the street corner.

"Where Hôtel OKKO, clad in semi-reflective aluminium panels, remains an unbroken mass, the InDéfense office building is split and shifted into smaller masses, each pushed in or extruded to open the long and narrow site to its surroundings," said the practice.

The hotel has 184 rooms spread across nine levels, a second public restaurant on the ground floor, and communal areas, including a sizable lounge for guests on the first floor. Studio Catoir designed the hotel's interior.