A low to medium rise building was selected as suitable for this cost modeling exercise as this constituted the target market as determined by the ASI Steel in Buildings Marketing Committee.Â A recent 4 story existing PT concrete building was selected for this study. Contractors, Rider Lovett Bucknall (QS), Cox Richardson (architect) and Arup (engineers) were employed to establish the alternative design in steel with OneSteel Manufacturing providing the base design and drawings for Arup to finalise.Â The model provided a base for which initial quantity surveyor file information could be used to understand what data is available to quantity surveyors in the market. Secondly, by updating with fabricator information, a relative comparison of steel framing vs concrete could be provided. In fact the relative cost comparison of steel vs concrete was tracked by state to show little difference in costs in the eastern states and SA with a small jump in WA. Concrete prices varied more widely by location, however. This model is proving useful as a tool to inform the fabricators interested in steel in multilevel buildings on the relative competitiveness of steel vs concrete for this building type. It is also proving invaluable as a mechanism to inform the Australian Institute of Quantity Surveyors AIQS on current cost data.
The results generated in late â€˜07 proved conclusively through the eastern states and in Adelaide that steel was typically competitive with concrete. In all cases studied steel was roughly cost equivalent with concrete, however adding in speed of construction, this cost equality was biased toward steel as the most cost effective option. This competitive edge was eroded however with the succession of steel increased over 2008 until steel was typically non-competitive with concrete in this model. Subsequent to this steel prices have started to fall significantly and it is anticipated that the competitive situation will return.