AUST – HENDRY building surveyors advise that there are specific requirements for access to roof mounted air conditioning units on buildings.  Part I1.2 of the Building Code of Australia (BCA) requires mechanical ventilation and hot water, warm water and cooling water systems in a building other than a system only serving a single sole-occupancy unit in a Class 2 or 3 building or Class 4 part to be maintained in accordance with AS/NZS 3666.2 and access provided by AS 1657.

Section 2 of AS/NZS 3666.2 requires easy and safe  access for cleaning, inspection and maintenance to all plant, equipment and components of air-handling and water systems of buildings by complying with the relevant requirements of AS 1657, AS 1470, AS/NZS 1892.1 and AS/NZS 2865.

AS 1657-1992 “Fixed platforms, walkways, stairways and ladders – Design, construction and installation” has specific requirements such as the cross fall for drainage of platforms and walkways should not exceed 1 in 35 or 1.64 degrees. There are no exceptions under AS 1657 for walkways not to be protected by guard railing other than at points of access or where there is a permanent structure not more than 100mm distance from the edge of the walkway which must give the same protection of guard railing. 600 wide expanded mesh on flat solid roofs does not comply with AS 1657. AS 1657 requires the walkway to be considered a platform owing to the fact that the walkway if level and provided the walkway/ platform is not more than 300 mm above the roof, defined on the edges, not at the edge of the roof or over a sky lite, it may not be necessary to provide guard railing provided the platform/walkway is 600mm wide.

Building Legislation Table

Refer to our Building Legislation table for further information on the building control process.