Achieving true affordability in housing requires innovation. This can be attained by looking at how design and construction methodologies can be streamlined and improved, without compromising structural integrity, liveability, or environmental impacts.
It’s this ethos that has led many within our industry to look at engineered timber products as the solution. A recent example of this is a Melbourne apartment project by HIA member Frasers Property Australia (formerly Australand) where they implemented a hybrid timber-based solution which slashes the cost of multistorey construction, dramatically speeds onsite progress, and results in a more affordable housing product.
To develop a solution that improves cost outcomes and onsite efficiencies, the HIA member worked in collaboration with engineers and suppliers to create a hybrid construction system, which utilises prefabricated engineered timber elements that can be built off-site and installed in modules.
While the use of prefabricated structural elements is common practice in residential building, the innovation comes with engineering and fabricating products that can meet the particular requirements of multistorey construction: accommodate wider spans, support greater weight, and conform to the additional fire and sound provisions specified by the building code for apartments.
Frasers first implemented the methodology in its five-storey Melbourne development, The Green, which was completed in 2014. The 57-unit structure was built from prefabricated engineered timber wall panels, roof trusses and large-span flooring cassettes, which were dropped into place using a lightweight crane.
At 2.7 x 8 metres, the flooring cassettes were large enough to span between load-bearing walls without additional propping. The building went up in overlapping steps: once a flooring cassette was in place, services were installed on the level below while the prefabricated wall frames were erected on the level above.
There are many benefits to the use of engineered timber products in circumstances such as this including the fact that they weigh much less than traditional materials such as concrete. As a result builders can utilise lighter crane systems on site, and the offsite construction work can be carried out by domestic trades.
The Green was completed a month ahead of schedule, and a subsequent cost analysis showed a saving of 25 per cent, compared to conventional concrete-based building methods.
For more information regarding this project and to see the benefits of combining engineered wood products and prefab construction techniques HIA members should view the latest issue of the HIA Housing magazine, electronic versions of which can be viewed under the HIA Publications tab at www.hia.com.au.
Craig Jennion
HIA Executive Director – Hunter