Aluminium frames are actually the most long-lived, also, in case you didn’t notice aluminium is a metal.
Cheap European windows tend to be plastic, expensive ones wood or aluminium though the latter aren’t generally used in domestic settings. The plastic ones often have wood in them for structural reasons but it’s so ugly noone would ever expose it.
Generally speaking the frames could hold longer if built better, but then you’d pay out of your nose for window panes that don’t fail earlier those inert gases aren’t easy to seal in for decades on end.
Aluminium frames are actually the most long-lived, also, in case you didn’t notice aluminium is a metal.
Cheap European windows tend to be plastic, expensive ones wood or aluminium though the latter aren’t generally used in domestic settings. The plastic ones often have wood in them for structural reasons but it’s so ugly noone would ever expose it.
Generally speaking the frames could hold longer if built better, but then you’d pay out of your nose for window panes that don’t fail earlier those inert gases aren’t easy to seal in for decades on end.