How do you ensure extreme structural safety, specifically preventing sash falling?

We implement a "Redundant Safety Protocol" to eliminate any risk of falling through two critical layers:
Windows (Redundant Protection): We utilize premium hardware from German brands and field-proven Chinese manufacturers, all subjected to strict endurance cycles. Every window is further equipped with a Stainless Steel Safety Tether (Anti-Fall Chain). This secondary failsafe ensures the sash remains secured even under unpredictable extreme stress.
Doors (Load-Bearing Logic): Our engineering rule is absolute: the load-bearing capacity of every hinge must significantly exceed the door's weight. By maintaining this safety margin, we have achieved a Zero-Fall record globally. We don't just hang doors; we anchor them with calculated certainty.