For windows in certain places building regulations state that safety glass must
be used. This is glass that has been strengthened or reinforced.
Safety glass should be used in doors, and windows that are within 1 ft (30cm) for
the door, or windows that are within 2ft 7 inches (80cm) from the floor.
If any part of the window falls into either of these categories, safety glass should
be used for the whole window.