Timber vs steel frame: which to build with?
The frame you never see does a lot of work. How timber and steel wall and roof framing compare on termites, straightness, movement and more.
The frame is the skeleton of your home, hidden inside the walls and roof once the house is finished. In SA and Victoria timber framing is the traditional and most common choice, with steel framing offered by some builders. Both meet the same standards, so the decision is about the quirks of each material and what matters for your block.
| Timber frame | Steel frame | |
|---|---|---|
| How common | The traditional default | Less common, offered by some builders |
| Termites | Needs termite protection and management | Not a termite food source |
| Straightness | Can shrink or warp slightly as it dries | Stays dimensionally stable and straight |
| Working with it later | Easy to fix and alter with common tools | Needs the right fixings and know-how |
| Thermal bridging | Less heat transfer through the frame | Conducts heat, so detailing matters for energy |
| Trades | Every carpenter knows it | Fewer trades specialise in it |
The termite question
This is the one most people ask about. Steel is not a food source for termites, which is a genuine plus in high-risk areas. Timber is perfectly fine with proper termite protection and management, which is standard practice, but it is a system you need to maintain over the life of the home.
Straightness and energy
Steel stays dead straight and stable, with no knots, shrinking or warping as a timber frame can have as it dries out. The flip side is that steel conducts heat, so your builder needs to detail the walls carefully with thermal breaks to keep your 7-star rating on track. Timber has less thermal bridging to begin with.
Timber frame
- Familiar to every builder and carpenter
- Easy to modify and fix later
- Less thermal bridging than steel
- Renewable material
- Needs termite protection and ongoing management
- Can shrink, twist or warp a little as it dries
- Quality varies with the timber
Steel frame
- Not a food source for termites
- Stays straight and dimensionally stable
- Consistent quality, no knots or warping
- Light and strong
- Conducts heat, so needs careful thermal detailing
- Fewer trades are set up for it
- Alterations need the right fixings and skills
- Not offered by every builder
Timber is the familiar, flexible default that every trade knows, and it is fine with standard termite protection. Steel earns its place where termites are a real worry or you value a perfectly straight, stable frame, as long as your builder details the thermal breaks properly. Either can deliver a great home.
Still weighing it up?
Tell us about your block and what you want, and we will match you with three builders across SA or Victoria who do this sort of work well.
Match me with 3 buildersCommon questions
Is a steel frame better than timber?
Neither is strictly better. Steel resists termites and stays perfectly straight, while timber is familiar, easy to alter and has less thermal bridging. The best choice depends on your termite risk, your builder and what you value.
Do steel frames have problems with heat?
Steel conducts heat, so without careful detailing it can create thermal bridges that work against your energy rating. Good builders use thermal breaks and insulation detailing to manage this, and the NatHERS assessment confirms the result.
Are timber frames safe from termites?
With proper termite protection and management, which is standard on new builds, timber framing is perfectly safe. It is a system to maintain over time rather than a set-and-forget feature, which is why some owners in high-risk areas prefer steel.
Can I renovate a steel-framed house later?
Yes, but alterations need the right fixings and someone comfortable working with steel. Timber is generally easier to modify with common tools, which is worth bearing in mind if you expect to change things down the track.