Bouygues Batiment Ile-de-France to renovate highest tower in la Defense business district
Bouygues Bâtiment Ile-de-France, Bouygues Construction's subsidiary operating in the Paris region, has signed a renovation contract worth more than 300 million euros with Axa, Beacon Capital and Cogedim for the CB31 Tower (1) in La Défense.
The renovation of the CB31 Tower is part of a major programme to modernise La Défense in order to ensure that the business district continues to appeal to users and investors. It is a world first in terms of scale and technical complexity.
The building, which comprises three wings and stands 155 metres tall with 40 storeys above ground, will be raised 10 storeys to reach a total height of 218 metres and become the tallest building in La Défense. The works also include 10-storey "levelling" of upper floors. The office floor space will be increased by nearly 10% to 87,000 sq. metres. The entire structure will be reinforced and the building envelope will be totally rebuilt with close to 50,000 sq. metres of slope glazing and curtain walling, including 30,000 sq. metres of naturally ventilated double-skin façade.
Renovation lead times and road traffic complications at the La Défense site call for particularly rigorous management of works phasing (cramped storage space, unloading areas, etc.).
The scale and technical complexity of the renovation project required Bouygues Construction to pool its broad range of skills in geotechnical investigations, special foundations, structural design of high-rise buildings, structural steelwork, façades, pre-stressing and renovation.
The CB31 Tower will win High Environmental Quality (HQE) certification as part of a far-reaching sustainable development approach.
The renovation work will be carried out by the Rénovation Privée unit of Bouygues Bâtiment Ile-de-France and will last three years. Close to 1,000 people will work on the site at peak periods.
The contract bolsters Bouygues Construction's position in La Défense. Bouygues Bâtiment Ile-de-France has built and/or renovated a large number of skyscrapers (Exaltis, Opus 12, Cœur Défense, Total Tower, Areva Tower, Vista Tower, etc.) and is currently completing construction of the T1 Tower.
(1) Previously known as the Axa Tower.