The most efficient of the METRA Building lines, characterized by the HES system, High Energy Saving, ideal for those looking for an essential design achieving maximum brightness and transparency with excellent thermal and acoustic insulation performance. Focus on NC 90 STH HES, the first window entirely in aluminium to obtain the prestigious certification “ClimateHouse Quality Window” in Gold class. This label, issued by the Agenzia CasaClima, an impartial third-party agency, guarantees the energy quality of the window and the installation of counterframe and frame made in a workmanlike manner.