THE DELOITTE ADMINISTRATIVE BUILDING WILL ACCOMMODATE 2300 EMPLOYEES AND IS PART OF A DISTRICT WITH A HIGH URBAN MIX THAT IS DEVELOPING SOUTH OF THE CITY OF LUXEMBOURG.This new building is built according to an ecological approach and aims for BREEAM "very good" certification.It consists of several buildings resting on a common base: a 17-storey building, a 6-storey second building and a covered street serving as an atrium and connecting the two latter. It includes a canteen, a restaurant, a multipurpose room, an auditorium with 199 seats and is equipped with 12 elevators.THE BUILDING IS DISTINGUISHED BY ITS LARGE "URBAN WINDOW" WHICH SERVES AS A TERRACE FOR VARIOUS EVENTS.The lighting, mainly composed of LEDs, adjusts according to the external brightness and occupancy. The atrium and auditorium are equipped with scenographic lighting devices. The building is cooled by cooling units, whose calories from the production of chilled water are distributed via reversible ceilings.Ventilation is provided by air handling units, equipped with heat recovery units and using an adiabatic cooling system.This principle is based on the exchange of energy between air and water, which allows the building to be cooled from 7 to 8°C. It allows significant energy savings to be made but also improves air quality.THE VENTILATION SYSTEM IS COMBINED WITH HEAT PUMPS. THESE, COUPLED WITH THE AIR HANDLING UNITS, BRING THE OVERALL EFFICIENCY TO MORE THAN 77%, I.E. BEYOND THE VALUES ENCODABLE IN THE CPE.The building was connected to the district heating system. Heat is distributed in both buildings via reversible ceilings. The atrium and fireplace are equipped with a floor heating system.In order to reduce the energy consumption related to the production of cold, an air cooler supports the production of refrigeration units up to an outside temperature of 10°C. These technical installations allow the building to achieve an energy class AB, an extremely satisfactory result for a building of this size.Several types of spaces have been designed: traditional workstations, collaborative spaces, meeting rooms or even concentration areas, all equipped with the latest technological systems. The technology will also be used in a "green-house", which will be located on the urban terrace on the 7th floor.This avant-garde space will allow teams and customers to test technologies related to the Big Data domain. To guarantee maximum user comfort for employees, sub-ceiling heights have been chosen, creating additional technical constraints.The sprinkler system could only be installed in car parks. This was treated with high fire stability ceilings (60 minutes) for the rest of the buildings.renewable energies space management, integration into the mobility site construction products and materialsTHE KNX SYSTEM INSTALLED IS AN INTELLIGENT CONCEPT FOR NETWORKING AND CONTROLLING HOME AUTOMATION THAT SIGNIFICANTLY INCREASES LIVING COMFORT AND AT THE SAME TIME ENSURES GREATER SAFETY AND LOWER ENERGY COSTS.In addition, particular attention was paid to the choice of materials used in the main installations in order to minimize the energy footprint of this construction.