Yves Gabriel, Chairman and Chief Executive Officer of Bouygues Construction, said: “The renovation of Challenger, which has been carried out by Bouygues Construction teams, has achieved its objectives of increasing the building’s energy and environmental performance while improving the working environment for 3,200 employees. Challenge is a showcase for the Group’s expertise and a physical demonstration of Bouygues Construction’s ambition to be a leader in sustainable construction in both the new build and renovation sectors.”

Elan, a subsidiary of Bouygues Bâtiment Ile-de-France, was responsible for obtaining the certifications on this project.

Following the renovation, Challenger is now a positive-energy building¹. This performance has been achieved thanks to:
• A significant reduction in energy consumption, primarily by replacing 24,000 m² of double-glazed facade by a ventilated double-skin facade incorporating an automatic blind. In addition, as in an eco-neighbourhood, Challenger is equipped with a thermal water network which optimises the consumption of the heating and air-conditioning systems by transferring calories between the various buildings of the site.
• On-site power generation, thanks to the installation of 25,000 m² of photovoltaic panels, 300 m² of hybrid thermal/photovoltaic panels, 75 geothermal sensors and a geothermal doublet.
• Numerous innovations, developed by Bouygues Construction’s Research and Development teams in conjunction with industrial partners, among them a new air-conditioning system, a system of individual LED lighting, a system enabling photovoltaic panels to operate individually, hybrid solar panels producing both hot water and electricity, individualised management of blinds, etc.

Beyond energy-related issues, these certifications acknowledge the full range of Challenger’s pro-environment achievements, embracing energy, water, waste and the comfort of employees. 80% of the waste generated during the works were recycled. The consumption of mains water has been halved thanks to the creation of a phyto-purification installation which treats the site’s wastewater and stormwater while encouraging the development of varied flora and fauna.

Particular attention has been given to biodiversity over the whole 30-hectare site. Challenger has obtained the BiodiverCity® label, the first international label to take account of biodiversity in property projects, and it is part of the “Jardins de Noé” programme run by Noé Conservation, which encourages the preservation of biodiversity. In addition, Natureparif, the Agency for Nature and Biodiversity in the Île-de-France region, has awarded the EcoJardin label to Challenger in recognition of its environmentally responsible management practices.

The maintenance and operation of the site are managed by Bouygues Energies & Services, a subsidiary of Bouygues Construction, which has worked on the project right from the design phase in order to optimise costs throughout the building’s entire lifecycle.

¹Conventional scope