Some owners have questioned that since the property management company is maintaining the external wall of the building, the glass outside my window should also be within the scope of maintenance.

Look at the structure of your house. If it is a wall (made of brick)+window, then the glass outside the window does not belong to the external wall. After the warranty period, the owner will compensate for the damage, including self-explosion. If it is a glass curtain wall, the window is considered as a part of the wall. If it is damaged, it should be repaired by the property company, and cleaning is also the responsibility of the property. However, there is no strict division in the current laws and regulations.