Our positive-energy head office

Nearly thirty years after it was built, the head office of Bouygues Construction has undergone a complete transformation and is one of the very first positive-energy renovated buildings. Showcasing the Group’s expertise, the site has become a flagship example of sustainable renovation.

Sougra Mamodaly,
Bouygues Construction employee at Challenger
“The office equipment is more modern and ergonomic, the storage space is more functional and there is much less noise in the open-plan offices than previously. The working zones are more personal, and I particularly appreciate the installation of cubicles on every floor which allow more confidentiality. And an important final point: the replacement of our old dustbins by recycling bins.”


The modernisation and extension of working and living space is central to the renovation of Challenger. The goal was to create a more pleasant working environment for the 3,200 employees working on the site. This has resulted in an overhaul of workspaces and car parking areas, as well as the acoustic and thermal insulation of the building. 


Challenger is experimenting with latest-generation equipment to achieve optimal management of energy. It has the strong ambition of achieving a tenfold reduction in consumption. Built in Guyancourt in 1988 on 30 hectares of green land, Bouygues Construction’s head office was originally considered to be a showcase for 20th century technology. The Challenger site’s makeover in 2014 turned it into a benchmark project for energy renovation and environmental management thanks to its eco-efficient systems for recovering, storing and transforming energies.


The majority of glazed facades were replaced by a ventilated double-skin facade that improved the thermal performance of the outer shell, thanks to the circulation of natural air. The building has also opted for relocalised electricity production, harnessing solar and geothermal energy. It was awarded the BBC (low energy-consumption buildings) label for new buildings, which is extremely rare for a renovation project, and it obtained triple LEED, HQE and BREEAM certification, meeting the strictest international standards with regard to green building.


Challenger makes careful use of the site’s natural resources to produce the green energy it requires to operate. The site harnesses the constant temperature of the earth, using 75 geothermal sensors at a depth of 100 metres. The most recent innovations in photovoltaic technology further boost Challenger’s energy self-sufficiency and performance. The building incorporates some 21,500 m² of the latest hybrid photovoltaic panels spread over terraces, roofs and a specially built solar farm. Meanwhile, water consumption has been reduced by the creation of 2,800 m² of filtering gardens.

Human capital

The new interior installations at Challenger have been designed with our employees in mind, and in consultation with them. This was the case for 100 new dedicated meeting spaces that have been created, along with 1,500 m² of new offices. Many features have been added or renewed with the aim of improving our employees’ working environment and offering them the highest possible levels of comfort, performance and safety. Examples include more individualised lighting, glazed partition walls, automated blinds to reduce glare from the sun, more ergonomically designed and better isolated zones for reprographics and for relaxation, and 400 additional parking spaces – all helping to improve the quality of people’s daily work.

In Short
saving in water consumption performance
of the facade replaced by a double-skin facade with very high thermal
25,000 M²
of photovoltaic solar panels