The NIRON PPR CLIMA system was installed for the cooling towers of Quatuor Building site in Brussels, Belgium. Quatuor Building is a new office building of 60.000 m² situated near the Rogier square in Brussels, to replace the actual “Noord Building”. Sustainability objectives are ambitious: reaching a minimum BREEAM “Excellent” rating in the design phase and developing a Nearly Zero Energy Building design. A microclimate analysis and due diligence work on the energy concept design (within the framework of the environmental permit application) were carried out. Among other things, the company analysed the location of solar screens, the technical details of HVAC systems (geothermal heat pump etc.) and proposed different improvement measures. They also analysed in detail the solar impact of this urban project on its surroundings, which allowed to optimize the different heights of the building. Finally, Computational Fluid Dynamics (CFD) calculations were used to analyze pedestrian wind comfort and mitigation measures were proposed to improve the wind comfort (location of the entrance to the building, landscape design and adapted design of the shape of the building envelope). Thanks to the close collaboration among all parties, the team was able to report fast and effectively towards the permitting authority and present a project with improved sustainability regarding the original design. Butt welding, electrofusion welding and prefabrication were used for the special angles. NIRON CLIMA is available in large diameters, minimises condensation and prevents corrosion. NIRON is a complete polypropylene pipe and fitting system for the distribution of hot and cold water in plumbing and air conditioning systems, for the conveyance of drinking water and alimentary fluids, industrial plants and for the transport of compressed air and chemical substances. The pipes and fittings that compose the NIRON range are manufactured using random copolymer polypropylene (PPR80 and PP-RCT), a plastic material with a special molecular structure ensuring high mechanical resistance and duration, even at high temperatures and pressures.