realestate.com.au has reported the sharpest jump in home construction prices in almost four years, with conflict in the Middle East and the oil price move behind it named as a driver. If you are quoting new builds, extensions, decks or fitouts right now, building material price increases of that shape are not an abstract economic story. They land in the gap between the day you price a job and the day you order the material.
That gap is the only part of this you actually control. So that is where the work is.
Why an oil price move reaches a residential job site
Crude does not just move the price of diesel. It moves the price of anything made from petrochemicals or moved by truck, which on a standard house job is most of the pallet:
- Anything polymer based. PVC stormwater and sewer pipe, sarking and vapour permeable membranes, geotextile, waterproofing membranes, paint and adhesive resins, poly water pipe, insulation facings.
- Cartage on everything heavy. Concrete, sand, aggregate, bricks, blocks, plasterboard and roof tiles are priced with the truck in them. Diesel up means delivered rate up, even when the ex works rate has not moved.
- Plant and wet hire. Excavators, bobcats, tippers, concrete pumps. Fuel is a line item in every one of those rates.
- Bitumen products. Driveway work, some membranes, ag line wrap.
Steel and cement are energy intensive to produce as well, so they tend to follow with a lag rather than jump on the same day. That lag matters for how you stage your ordering.
Where building material price increases actually show up on a house job
Not evenly. On a typical single storey slab on ground build, the exposure is concentrated in the early trades, which is also where you are most likely to have already locked a price with the client.
Slab stage is the clearest example. Concrete is cement, sand, aggregate and water, and the cartage sits over the top of it. A 300mm bump in your waffle pod depth or a slab area you eyeballed instead of measured will cost you far more than the market move ever will, so measure first and argue about the rate second. If you are checking your volumes before you send a supplier your order, run them through the concrete calculator rather than working off the engineer's plan area in your head.
Frame stage is different. Timber pricing tends to move on shipping, mill capacity and demand rather than on crude directly, but your framer's cartage still moves. Watch out for the substitution trap here: if your supplier offers a different grade or species because the specified one is short, the span tables in AS 1684 are what decide whether that substitution is legal, not whether it looks close enough on the stack. Get the engineer or the truss supplier to confirm it in writing before it goes on the truck.
The Australian Bureau of Statistics publishes Producer Price Indexes for the construction industries quarterly, including output of house construction. That is the number to check against when a supplier tells you the market has moved, because it tells you whether the whole market moved or just your account.
Your quote validity window is the real hedge
Most small builders do not have the volume to hedge a commodity. What you do have is control over three things on the document you send the client.
A stated validity period. Thirty days is common. In a volatile quarter, fourteen is defensible and worth saying out loud, with a plain line explaining why. Homeowners understand fuel prices better than they understand your margin.
Supplier quotes with dates on them. If your quote to the client is built on supplier pricing, ask for that pricing in writing with its own expiry, and keep the two aligned. A client quote valid for 30 days sitting on a supplier quote valid for 7 is a loss you have already written yourself.
Honest provisional sums. A PC or PS item that you have deliberately set at a realistic level is far better than a fixed price you cannot hold. Quotes to homeowners must show a single total price including GST, so make sure the GST treatment on those items is right before it goes out.
Be careful about assuming you can simply pass an increase on. In several states, cost escalation and rise and fall clauses in domestic building contracts are restricted or banned below a contract value threshold. Check your own state's building regulator for the current position before you write one in, because getting it wrong is a contract problem, not a pricing problem.
What to do this week
- Pull every quote you have out with the client and check the expiry date. Anything past it, reissue.
- Ring your three highest spend suppliers and ask what is locked and until when.
- Order long lead, price exposed items for jobs that are already signed. If the contract price is fixed, the exposure is yours.
- Go back through your last five completed jobs and compare quoted material cost to actual. If you are consistently under by more than a few percent, the problem is your rates file, not the news.
That fourth one is the one builders skip, and it is the one that pays. Estimating accuracy is a habit, not an event. If you are still doing it across a spreadsheet and a pile of supplier emails, the comparison is too painful to ever actually run, which is most of why it does not get run. There is a rundown of the options in our guides to construction estimating software and construction project management software if you are weighing up a change.
Global events will keep doing what global events do. A quote with a date on it, supplier pricing that matches, and a rates file you actually update is how you stop them landing on your margin.
The Built Simple app is free to download on iOS and Android, with the calculators open to everyone and no signup needed. Worth having on the phone next time a supplier rings mid morning with a new rate.
