Majunga, an “exceptional” HQE tower
Emblematic of the revival of La Défense, the Majunga tower stands out through its strong architectural ambition and its environmental performance.
Building began on the Majunga tower in July 2014 in the heart of the business district of Paris-La Défense. This high-rise building, with its remarkable environmental excellence, had already obtained the BBC (Low Consumption Building) label during its design phase, as well as HQE (High Environmental Quality) and BREEAM (BRE Environmental Assessment method) certification, both at “Excellent”.
Winner of the BREEAM Awards 2012, it achieved a score of 77.43% at the late design phase, “the highest level of environmental performance in Continental Europe, out of all assets in 2011” explains the developer Unibail-Rodamco. The energy efficiency targets of the tower (44 floors, 69,500 sqm net floor area) primarily rely on:
- a high-performance building envelope that stands out through its façade;
- natural ventilation openings adapted to the constraints of a high-rise building and controlled by BMS (centralised building management)
- a 250 sqm photovoltaic system;
- optimisation of the amount of natural light and control of artificial lighting
- recovery of rainwater for the gardens on the terrace
Its outstanding environmental performance will enable users to significantly reduce their energy consumption and their carbon footprint. “Majunga is a strong and balanced project across all areas of environmental performance, and is not only efficient in terms of energy matters but also in the management of water, materials, waste and movement, while respecting the original intentions of the architectural agency Viguier” insists Thierry Deberle, manager of Elioth Energie & Environnement at Egis.
Majunga is also the first tower in La Défense with outdoor spaces on each floor (loggia or balcony)
Egis carried out the structural studies for the tower, overall calculations of operational details through testing soil-structure interaction, dynamic behaviour and prediction of subsidence.
For this project, Egis teams also contributed their skills and expertise to environmental engineering tasks, advanced HQE-BREEAM studies, optimisation of daylight through simulation, energy consumption and comfort through dynamic thermal simulation, optimisation of natural ventilation through ventilation simulation, waste and water management, monitoring of the green construction and the HQE and BREEAM certification process.