With the increased demand for densification and the current trend for multi storey building design it is worth noting  requirements for separation of vertical openings in external walls. To minimize the risk of fire spread from one floor to another provides deemed to satisfy construction requirements. These requirements apply to residential buildings (apartments and hotels) of 3 storeys of more, other commercial buildings (class 5, 6, 7 & 8) of 4 or more storeys and class 9a (hospital) buildings of 2 or more storeys which are not protected by a fire sprinkler installation.

 The provision of fire sprinklers is deemed to be sufficient to prevent the spread of fire from one floor to another in which case the external wall construction restrictions do not apply. Similarly open- deck carparks are also exempt from the restrictions as it is considered unlikely that fire would spread between floors in these types of buildings as their open construction allows the dissipation of the effects of fire.

 Where vertical separation of openings is required it can be achieved by either of the following methods:

1. A non-combustible spandrel or other non-combustible vertical construction having an overall height of 900 mm or more, extending at least 600 mm or more above the upper surface of the intervening floor.