What if the property does not allow the balcony to be sealed?

When buying a house, the balcony has been calculated in the construction area, so the balcony belongs to the owner's personal property, and the closed balcony property has no right to interfere. If the property is not allowed to close the balcony, then if people accidentally fall down (especially children) because the balcony is not closed, you can ask whether the property should bear the responsibility. See if the property dares to write you a letter of guarantee.