The six chamber pvc profile system with a classic shape of the sash, which encourages the application of French windows and doors made in this system in each type of buildings. FORIS 601 is a system with the installation depth amounting to 72 mm and a wide frame and sash notch enabling the application of heat-insulating glass packets with a thickness up to 42 mm, including the three-panel sets. The thermal insulation coefficient of FORIS 601 window profiles amounts to 1.2 W/m2xK. These parameters of FORIS 601 pvc profiles translate into the excellent thermal protection of buildings, so important at the time of the permanently increasing costs of energy.