The Ongoing Debate: Timber vs. Steel
With over 30,000 homes built in New Zealand every year, the industry battle between timber frames and steel frames is intense.
Members of the timber team argue that steel homes have a larger carbon footprint, poor thermal performance, can be susceptible to corrosion and rust, transmit sound more readily within the home, and may even interfere with internet connections.
Supporters of steel frame homes, on the other hand, highlight benefits such as enhanced fire resistance, design flexibility, and resistance to pests, mould growth, and decay.
Still, interest in light gauge steel frame (LGSF) homes is growing, accounting for 6% of the homes built in New Zealand. Most of our roofs are steel, so why not the frame, too?
Addressing Common Concerns
Greg Jones, the deputy chair of NASH (National Association of Steel-Framed Housing), refutes many of the common arguments against steel homes, some of which have diminished as the industry has evolved.
Thermal Performance
One such example is thermal performance. Greg says this is addressed by mandating the level of insulation used in a steel-framed home.
“Thermal transfer is not solely a steel frame issue; timber is prone to this,” he says. “Take a look around next autumn and observe the shadows of the studs on the exterior walls of timber homes—that's thermal transfer.”
Greg cites a current NASH project that aims to move LGSF homes into the next generation. “There are some exciting products that can improve efficiency and fit in with the machine manufacturing accuracy of LGSF,” he says.
Sound Transfer
Another concern about steel frames is the so-called ‘tinny feeling,’ but as an LBP carpenter, Greg says there’s nothing tinny about steel-framed homes. They fully comply with the New Zealand Building Code, and once the house is lined, there’s no discernible difference.
He notes that sound transfer needs to be considered no matter what material is used. “Sound does travel through steel, but we aren't building a railroad,” he remarks. “Using good design and materials that absorb, isolate, or deflect sound is essential to creating a liveable environment.”
Cost Considerations
And we cannot ignore money. NASH states that while LGSF can initially be more expensive than other materials, its long-term benefits make it more cost-effective. “In general, we are on par or up to 10% cheaper than our timber counterparts,” Greg says, especially when considering every component of a timber frame, down to the last brace and purlin.
Additionally, steel frames are typically built quickly, leading to greater efficiency, schedule certainty, and pre-punched services, which save time and onsite mess. Builders also experience less fatigue working with steel compared to timber frames.
Making the Right Choice
Greg advises anyone considering a steel home to align with an architect and NASH fabricator. Finding industry experts is crucial. A full 3D model project render can be created to allow homeowners to manipulate and visualise how their rooms will look.
“We are experts in modular building, so plans and details are comprehensive without being incomprehensible,” he says. “Be aware of the hold timber has on our industry and what that means for the information you have been gathering while doing your due diligence.”
