Highly original with its wedged shape and twenty loggias looking out over the city, the Majunga Tower is the second highest skyscraper in the business district of La Défense, after the First Tower. Designed by the architect Jean-Paul Viguier and built on behalf of Unibail-Rodamco, it marks the return of Eiffage to La Défense, where the Group previously built the Ariane and Défense Plazza towers.
It took forty months of building work and 600 people at the peak of construction activity from all branches of the Group (Eiffage Construction with its “Études et Structures et Méthodes plus” design offices, Eiffage Energy for the electrical works, façade specialist Goyer, and Eiffage Public Works for part of the works at the base of the tower), to complete this building, which has 47 floors and weighs 135,000 tons.
© Mohamed Khalfi.
It represented a technical challenge given the very narrow plot dimensions (3,500 m2)! Building on a plot the size of a postage stamp with no storage area meant that logistics and traffic management were run with almost military precision, with around 50 truck deliveries a day.
Following special foundation work, where 450 jet grouting columns were injected under the building’s maximum weight points, construction of a three metre thick slab, using 6,000 m3 of concrete, was the first key step before construction of the seven levels of foundations. Special high performance concrete was used throughout. The formwork for the central core required 400 tons of materials and 120 semi trailer trucks. In the design phase, aligning structure movement with tolerance requirements of façade specialist Goyer (a subsidiary of Eiffage Métal), which installed the 35,000 m2 of facades, was also a challenge.
From an energy perspective, with primary energy consumption of less than 80kWh/m2/year, the Majunga Tower is four to five times more energy efficient than towers built in the nineties. Equipped with 250 m² of solar panels, the Majunga Tower is the first new building in France to receive BBC certification in its design phase and the first office tower in continental Europe to obtain BREEAM Certification at Excellent level. It is also aiming for NF Tertiary Buildings HQE as well as the BBC Effinergie 2005 label (RT 2005 - 1950 %). The building’s technical system controls lighting, office air-conditioning and shutters.
The project represents 200 million euros of construction works, as well as 50 million euros of project management and client support.