To limit the probability of persons contacting or colliding with items at ceiling level, which could lead to harm to persons.
To limit the probability that exits and access to exits will have an insufficient ceiling height to permit efficient egress in an emergency situation, which could lead to delays in the evacuation or movement of persons to a safe place, which could lead to harm to persons.
To supersede the requirement stated in Sentence (1) and permit a reduction in the minimum clear height of storeys in storage garages, on the basis that the occupant load is limited and most occupants are in vehicles.