THE BUILDERS CHOICE Timber & Steel Framing
McDonalds, Mundaring
www.steelscene.com.au
‘‘Speed and convenience: framed walls can be modularised and pre-fabricated, and then assembled quickly once delivered on-site’’ the amount of embodied energy compared to a timber framed wall (169- 377MJ/sqm). While materials with high embodied energy are not necessarily "bad", high embodied energy often means high carbon emissions, and so we will need to think more carefully about the materials used in building construction as we transition to a lower carbon economy. These are some of the reasons why the builders I work with and many of the homes I design today tend to use framed construction (mainly timber, but sometimes steel). Some of the advantages to framed construction include: Speed and convenience: framed walls can be modularised and pre-fabricated, and then assembled quickly once delivered on-site. For the houses where I have still used cavity brick, upper floor walls are built from framed construction, eliminating the need for brick hoists. Services such as plumbing and electrical wiring can be easily installed inside the wall frames – no need for brick chasing. Flexibility and choice: There are variety of cladding materials and external finishes available that can be used in conjunction with framed construction – this makes it possible to articulate the facade of a building in different materials, which can help to create more interesting designs. Framed construction can also accommodate changes in the building geometry such as projecting or recessed walls, which is helpful since I'm an architect and tend to design more complicated shapes! Performance: With appropriate levels of bulk insulation and sarking correctly installed as part of the external wall, framed construction can provide a high level of thermal performance,
92 The Builders Choice Magazine – March 2019
while also avoiding moisture and condensation issues. Steel framing requires the addition of a thermal break between the external cladding and the steel studs to minimise thermal bridging, but there are easy to install products available for this purpose. Framed construction can sometimes experience issues with sound transmission compared to masonry construction, but there are a variety of factors that can impact this other than just the wall construction. Incorporating higher density wall insulation or plasterboard, resilient mounts and ensuring gaps are properly sealed can also help to address unwanted sound transmission. Cost, of course, is probably the most significant, influencing factor in the decision making process: we've found that for the houses I design, framed construction is more cost-effective compared to cavity brick and masonry construction. As I wrote earlier in this article, there's nothing wrong with brick, and it can still be a cost-effective way to build a well-performing home; new and innovative building materials are not necessarily better. However, we are developing a greater understanding about the impacts of the building and construction industry, and now consider a wider number of factors when deciding how we build. I've found the ubiquitous use of brick isn't always the best option, and saying "but that's the way we've always done it" is becoming a less convincing justification for keeping things unchanged. I believe greater choice – brick, framed and no doubt others – will ultimately result in better quality, higher performing buildings that will benefit homeowners as well as industry. *http://www.yourhome.gov.au/materials/embodied-energy