A 231-metre sleek and bevelled silhouette thrusting into the sky, the First Tower holds the French record for height. This was the heaviest refurbishment programme carried out on an office tower in France to achieve High Environmental Quality (HQE) certification. It was an enormous challenge to remodel an ageing skyscraper while fitting it out with the most ultra-modern features. But the challenge was fully met: the 87,000 m² of office space – 10% more that the building originally contained – were handed over in 2011, following five years of design and construction, a month ahead of schedule!

The First Tower is no less pioneering in its geometry. It thrusts its bevelled arrowhead into the sky above La Défense, where all the tall flat-roofed towers congregate together, making an architectural statement like no other. The tower has retained its helix structure. The vertical extension of one wing and the layered lowering of the other two creates an extraordinary dynamic which makes it one of the principal focal points of the business district.

Ever since the programming and design phase, the First project has been engaged in a particularly challenging HQE certification process. The building as delivered bears witness to a very high level of ambition: five of the fourteen certifications sought were granted at “very high performance” levels. The project partners set stricter targets than those required by  the certification guidelines, concentrating their efforts particularly on waste management and reduced energy consumption. The focus on energy issues was also reflected by the choice of a gas heating system and heat pumps. Such features as these allowed it to obtain the particularly stringent THPE (Very High Environmental Performance) label.