Part G4 Construction in alpine areas
GP4.1 External doorways
An external doorway from a building in an alpine area must be installed so that opening the door is not obstructed by snow or ice.
The Objective of this Part is to safeguard occupants in alpine areas from illness or injury from an emergency while evacuating a building.
GO4 applies to a building constructed in an alpine area and overrules other provisions of the BCA.
Protection while evacuating
GO4 specifies that occupants of buildings in alpine areas must be protected while evacuating in an emergency. The protection measures are only required to assist while the building is being evacuated.The additional measures included in Part G4 are necessary because of the conditions which can exist in alpine areas.
Precedence over other BCA provisions
GO4’s Application provision clarifies that if there is any contradiction between the requirements in this Part and the rest of the BCA, then the provisions of PartG4 will take precedence.
A building in an alpine area is to be provided with additional measures in view of the increased difficulties in fire-fighting and maintaining access and means of egress in snow conditions.
GF4.1 applies to a building constructed in an alpine area and overrules other provisions of the BCA.
GP4.1 requires external doors to continue to operate effectively in snow conditions so people can leave in an emergency by the normal egress route (i.e. the doorway).
Such a doorway must not be made inoperable by deposits of snow and ice. Care needs to be taken to avoid locating doorways where:
- snow falling from adjoining roof areas could affect egress paths; and
- re-entrant corners of a building increase the potential for snow to be trapped.
GP4.2 Structures forming pathways in snow conditions
A building in an alpine area containing external trafficable structures forming part of the means of egress must be constructed so that those structures remain, as far as practicable, useable under snow conditions.
Any external structures used as part of an egress route must remain accessible in snow conditions. An external balcony not designed for egress from the building would not need to comply.
To comply with this provision it is necessary to make sure that snow build up is avoided and that the surfaces reduce the potential for people slipping.
GP4.3 Control of falling ice and snow
A building in an alpine area must be constructed so that snow or ice is not shed from the building onto the allotment, any adjoining allotment, road or public space in a location or manner that will—
obstruct a means of egress from any building to a road or open space; or
otherwise endanger people.
Areas adjacent to the building should not be subjected to heavy deposits of built-up snow or falling ice which could harm:
- people evacuating (i.e. roofs must be designed to avoid depositing snow on egress routes from the building); and
- people using the area adjacent to the building (ie snow from the roof area should not cascade on to public thoroughfares and roads or on to adjoining property in a dangerous manner).
GP4.4 Fire safety systems in alpine areas
facilitate fire-fighting operations; and
alert occupants in the event of an emergency.
GP4.4(a) requires that a building have equipment to facilitate firefighting operations. With the increased risk of fire development and access problems for fire brigades in alpine areas, it is important that suppression equipment be available to combat a fire in its early stages of development, to possibly prevent the fire reaching an uncontrollable stage.
It is not intended that occupants fight a fire if there is any danger to them. It is essential that occupants be able to evacuate safely before untenable conditions are reached.
Care will need to be taken in design and construction to ensure that water in fire-suppression equipment will not freeze, making the equipment useless.
GP4.4(b) requires the installation of a system to alert occupants of an emergency. Where an external alarm is installed, care must be taken that the sub-zero temperatures do not freeze its mechanism.