3XN has officially debuted its first-ever French design just west of Paris’ La Défense business district in Nanterre.

Featuring a program that combines a traditional office and hotel accommodation through two separate volumes, joined along an east-west axis, that offer views of La Défense’s adjacent towers and Johan Otto von Spreckelsen’s monumental Grande Arche.

“As the first shape you encounter when arriving from La Défense, this building had to be eye-catching and dynamic,” 3XN Founding Partner Kim Herforth Nielsen explains. “The faceted façade and shifting volumes make it a standout in the busy district. The concept — two distinct but complementary designs — is unique in the area.”

The scheme makes use of semi-reflective aluminum panel cladding to distinguish the Hôtel OKKO as one unbroken massing, while its partner InDéfense office structure splits into smaller forms, extruding to “open the long and narrow site to its surroundings and add depth to the façade.”

An enclosed agora set between the two volumes is punctuated by a mural commission and spiral stairs. Inside the office function, another spiral staircase frames its entrance and offset north-facing atrium with expanded landings intended to facilitate conversation and team building amongst its tenant colleagues. 

“Stairs connect more than floors; they connect people,” Nielsen adds. “In this project, they are open and visible across all the floors and thread their way inside and outside of the building, making them a social and visual connecting element and making you more aware of your surroundings as you move through the building.”

The remainder of the structure includes a smattering of additional social spaces, with outdoor terraces situated leading up to the crown of the building and connected again by a network of exterior spiraling stairs. The rest of the copper-colored facade offers what 3XN calls a “dynamic play of push and pull” through its design of receding overhangs which play host to biophilic elements typical of contemporary office design’s intents on worker productivity and wellbeing.

Juxtaposed with this is the nine-story, 184-room hotel function, which includes a ground-floor restaurant and 3,230-square-foot lounge. It includes interiors designed by Studio Catoir, while the “shifting” effect Nielsen described on its exterior is accomplished by angular tinted aluminum cassettes that provide an alternatively metallic or transparent look to outside viewers depending on the time of day or location.

Both volumes’ facades are designed to high-level acoustic performance standards. The cassettes include perforated side-panel openings for ventilation sans any intrusive visible frames. “On such a long, visible site, the façade had to combine beauty and functionality,” Nielsen shares. 

The overall project will achieve WELL Silver, BREEAM Excellent and Very Good certifications. SRA Architectes aided with its site plan, which connects to the RER E Line extension and new M15 Les Groues station, seen as the source of a greater expansion of the district set to be enacted over the next few years.