BESIX has completed a major construction phase on the Triangle skyscraper in Paris, marking the end of a three-and-a-half-year period of intensive concrete works that have shaped one of the French capital’s most striking new landmarks.
Located in the city’s 15th arrondissement near the Parc des Expositions at Porte de Versailles, the 180-metre-high tower — designed by celebrated Swiss architecture firm Herzog & de Meuron — is now visibly transforming the Paris skyline.
The distinctive prism-shaped structure will become the city’s third-tallest building when completed in 2026, following the Eiffel Tower and Tour Montparnasse.
The milestone was reached after BESIX completed the final concrete pour on the 40th floor, concluding what the company called one of its most logistically demanding projects in recent years.
“We don’t always take the time to appreciate the full extent of the effort involved, but at this key moment in the project, we want to offer a heartfelt thank you to everyone, past and present, who has worked relentlessly to get us to this point,” said Koen De Rooy, BESIX France Project Director.
The Triangle Tower is rising from a narrow 200-metre by 45-metre site, previously considered unsuitable for vertical construction.
BESIX’s engineering and logistics teams devised a detailed strategy to manage limited space, ensuring minimal disruption to the surrounding urban area in southern Paris.
Over the past three and a half years, workers have poured approximately 70,000 cubic metres of concrete, installed 2,000 columns, and placed over 1,600 precast beams, with several hundred additional beams cast on-site.
The completed concrete slab surfaces now span about 90,000 square metres.
The tower’s 8,300 facade panels — made partly from recycled aluminium — are currently being installed, with more than 6,600 panels already fitted.
From December 1, construction shifted to the steel crown section, consisting of the final four structural levels that will define the building’s iconic silhouette.
Once complete, the 180-metre skyscraper will encompass a wide range of uses, establishing itself as a vertical urban hub.
Plans for the 42-storey building include office spaces, a Radisson Blu hotel, retail outlets, a medical centre, a daycare facility, and spaces for conferences and cultural events.
At its upper levels, visitors will find an observation deck and restaurant, offering expansive views across Paris.
The Triangle — also known as Tour Triangle — is being developed under the direction of Unibail-Rodamco-Westfield (URW), Europe’s largest listed real estate group.
BESIX, acting as the lead contractor, is coordinating closely with French engineering firms Setec (structure), Egis (fluids), and Artelia (project management) to ensure precision at every stage of construction.
Environmental performance plays a central role in the Triangle’s design.
The tower aims to achieve BREEAM Outstanding and HQE Exceptional certifications — standards that recognise best-in-class environmental performance in building design and operation.
Features contributing to these goals include geothermal heating and cooling, a double-skin facade for natural insulation, and 1,000 square metres of photovoltaic panels that will generate part of the building’s energy needs.
The project also connects to the Paris district heating network, which supplies largely renewable or recovered heat to over 50 per cent of households in the city.
In addition to energy efficiency, the tower employs recycled and low-carbon materials, such as aluminium facades made from reused metals.
BESIX noted that the project aligns with both Paris’ climate goals and France’s national commitment to carbon neutrality by 2050.
Beyond its architectural and environmental ambitions, the Triangle development is expected to generate about 5,000 direct and indirect jobs throughout its construction and operation phases.
Once open, it will serve as a major destination for business tourism and cultural exchange, reflecting Paris’ ongoing efforts to diversify its skyline and decentralise office activity beyond the traditional business districts.
Construction is progressing according to the 2026 completion schedule, when the fully assembled structure will become a new focal point of modern Parisian architecture — a sleek, triangular tower symbolising innovation and sustainability in Europe’s most visited capital.