The SI82 ALU INSIDE window system includes products with energy-saving 7-chamber profiles that support the insertion of PUR insulation foam. The products boast superior thermal performance and can be installed in better low-energy and even passive buildings (window Uw value up to 0.66 W/m2K). The profiles with the built-in insulation foam are certified by the Passivhaus Institut from Darmstadt. Aluminium reinforcing profiles give the product structural stability and positively impact its thermal characteristics.