Here are the approximate weights per square meter (kg/m²) of the most common glass types for balustrades:
10mm toughened: 25kg/m²12mm toughened: 30kg/m²13.5mm laminated toughened: 33kg/m²15mm toughened: 36kg/m²17.5mm laminated toughened: 50kg/m²21.5mm laminated toughened: 62kg/m²