Refurbishment of the Ministry of Defence




Ministère de la Défense / Opale Défense


Ateliers 2/3/4/ (architect + landscape designer) - Egis - Elioth (engineers)

Nature of the project

Large buildings, Tertiary, Restructuring, Landscape design


Refurbishment of the « Cité de l’air » :
Urban and landscape planning, offices and administration
Restauration, conference Center and library
Sports Equipments, child care center, central Fire Department, logistical and technical buildings., data center




Total area 8 ha
Demolished area 13.500 m²
New building area 6.000 m²
Heavy refurbishment area 47.500 m²
Light refurbishment area 109.000 m²
Outdoor equipments area 5.5 ha


Completion phase 1: september to april 2015
Completion phase 2: january 2017


phase 1 : 172 M €ht
phase 2 : 30 M €ht

Construction compagnies



©Nicolas Fussler ©RichardNicolas-Armée de l'air

Two transformation issues coexist here; a site more than 8 hectares in area but also the now somewhat disparate buildings constructed throughout the previous century.
The transformation depended on two main ideas:
– to make the site a unifying « mat » whilst the visible support of a new, completely pedestrian use of the site; and
– to inscribe this unity upon the buildings themselves.
Cleared of vehicles, the site becomes a vast meadow brought alive by its topography and the large and small building alterations, all decked in a deep brownish rust color. The 3,000-tree plantation, a large water basin, a sculptured staircase reinforce the extraordinary mutation.
As for the transformation of the buildings, it follows an internal logic specific to the typology of each building.

Three main buildings were identified:
– the ENSTA from the 1930s whose rehabilitation demolished the additions that partially disfigured it;
– the base of the elliptical tower with its two radical features – a depth of over 50m in places and the omni-presence of a circular configuration. Without denying it, a new meaning was given by systematically introducing daylight into the center of the mass; and
– the residential tower annex with the same excessive depth defect. There too, inserting a patio has given life to the new program.

Avant / Après
Tracés générateurs/ Interventions architecturale/ Intervention paysagères
Bâtiment BC (centre de vie) : Hall
Bâtiment BC (centre de vie) : restaurant RIE
Bâtiment BC (centre de vie) : rdc
La prairie
Cour bâtiment BC (centre de vie)
Bâtiment BC (centre de vie)
Bâtiments 28-30-32 (ENSTA)
Bâtiments 28-30-32 (ENSTA) : rdc
Bâtiment 28/30, (ENSTA) : bibliothèque / 30 000 ouvrages
Bâtiment 28/30 (ENSTA)
Escaliers de l'ENSTA
Auditorium de l'ENSTA
Bâtiment G (centre sportif)
Bâtiment G (centre sportif) : plans