FEATURES 21 LEED Certification: active ingredients Interview with Eng. Giorgia Lorenzi, LEEDme Trento LEED is the sustainability certification most widespread all over the world, its parameters (LEEDV4 from 2015) allows the design supply chain to reach constructive and technological innovative solutions. The certifications are not just for the new buildings, but they can be worn even on existing ones with a specific LEED evaluation standards O + M (LEED-Existing Building: Operation and Maintenance). This kind of certification intervention concern the plants and existing sub-systems efficiency and the building management. The certification value, as shown below, it’s not only technical but also social, living or working in a LEED certified construction means staying in a sustainable and low carbon footprint building.