Christian de Portzamparc, winner of the Pritzker Prize (‘Nobel Prize of architecture’) in 1994, parades his ‘open block’ concept with this 3-building project comprising Galeo, Dueo, and Trieo which mark the entrance to the Municipality of Issy-les-Moulineaux on the road from Paris. A glass-scaled nugget, a soft pebble, or ‘Chinese lantern’ as Christian de Portzamparc calls it, Galeo stands in striking contrast to the brown, mineral cement composite façades of Dueo et Trieo. After dark, when the building lights up, Galeo puts on a singular light show for drivers on the Paris ring road.
In 2007 the entire complex was sold to Spanish investor Naropa Properties. Galeo is the Head Office building of Bouygues Immobilier, while Dueo is occupied by the personnel of Bull and Safran. Trieo too is occupied by Safran.
In April 2009 Bouygues Immobilier was awarded the ‘Silver Pyramid’ in the ‘Immobilier d’Entreprise’ corporate properties competition for its Galeo, Dueo, and Trieo project. Prizes in the competition go to the best new projects the Paris region has to offer in terms of architecture, functionality, comfort, and energy savings.
Galeo, Dueo, and Trieo are certified against the HQE®Bâtiments Tertiaires High Environmental Quality standard for corporate buildings. They achieve a 20 to 32% energy saving relative to standard office buildings compliant with the 2005 thermal design code. To attain this saving, Bouygues Immobilier multiplied the application of technological advances.
- Concrete structure clad with a first skin of zinc comprising external insulation and a second skin of glass made up of 700 screen-printed ‘scales’. The space between the two skins affords protection against noise and creates a thermally insulating atmosphere.
- External blinds reduce or enable heat gain, depending on the season.
- Active chilled beams with low energy consumption.
- External blinds, chilled beams, and lighting appliances controlled by the Building Management System (BMS) for automatic temperature regulation aligned with weather conditions.
- Presence detectors in office floors, stairwells, washrooms, ca rparks, and meeting rooms to optimise use of lighting.
Galeo, Dueo, Trieo
3, boulevard Galliéni
92130 Issy-les-Moulineaux, France

- Net floor area in m²Net floor area in m²: 24 000 m²
- Occupant capacity: 1 800
- Year of handover: Galeo et Dueo : summer of 2009 Trieo : February 2010
- Architect: Christian de Portzamparc