30. A building shall be designed and constructed so that the combined dead, imposed and wind loads are sustained and transmitted to the ground, taking into account the nature of the ground—
(a)safely; and
(b)without impairing the safety of any part of another building.
31. A building shall be designed and constructed so that in the event of damage occurring to any part of the building, the extent of any resulting collapse will not be disproportionate to the cause of the damage.