Guide · Build cost feasibility
The $/m² rate is the headline.
The job is won or lost underneath it.
Construction cost benchmarks describe the construction line only. The all-in cost of delivering a finished home is built in layers, and the ones that get missed are where a feasibility that looked fine turns into a job that loses money.
Written by Brad Caldon, Founder, VIABUILD. Licensed builder (NSW) · Registered Building Practitioner (Class 1 to 9) · B.Construction Management (Hons)
01 / The basics
In plain English
The most-quoted construction cost benchmarks (the Cordell Construction Cost Index, Rawlinsons) describe one thing: the per-square-metre cost of the construction itself. That figure sits well above where it was before the pandemic, and it isn’t coming back down. But it’s the headline number, not the whole number. A practitioner’s feasibility builds the total delivery cost in layers on top of it.
The layers above the construction line
- Construction. The headline figure: the per-square-metre rate multiplied by built area.
- Site-specific costs. What the headline rate excludes: earthworks, retaining, services connections, driveways, fencing and landscaping.
- Statutory charges. Council and state government charges, developer contributions and infrastructure levies, which on a new lot in a growth corridor routinely run to tens of thousands of dollars before a slab is poured.
- Finance and holding. Interest on construction drawdowns and holding costs across a build that now takes materially longer than it used to.
- Time risk. Contract variations, weather days, trade availability and the elevated rate of subcontractor and head-contractor insolvency.
- Transaction costs. Stamp duty, GST treatment and conveyancing at the back end.
Add those layers on top of the construction figure and the all-in cost of a new home is a long way above the headline $/m² implies. In a number of growth corridors, that all-in cost of building new now exceeds the price of an equivalent established home nearby. That equation is what breaks new supply, and, at the level of a single job, it’s what turns a feasibility that penciled into a build that loses money.
02 / The reality
Where builders get stuck
Feasibility built on $/m² alone
Taking the construction benchmark as the whole cost. Everything the headline rate excludes still has to be paid before keys are handed over.
Site costs underestimated
Earthworks, retaining, services and landscaping vary enormously by block and are routinely the first thing a quick feasibility gets wrong.
Statutory charges forgotten
Council and state charges, contributions and levies on a new lot can run to tens of thousands of dollars, and they land before construction even begins.
Holding cost ignored
Higher rates and longer builds mean every project carries more financial drag from finance drawn to occupancy. A feasibility with no holding line is optimistic by default.
Time risk not carried
Variations, weather and trade availability stretch programs. With no contingency for time risk, the first delay eats the margin.
The feasibility never gets checked
Without committed-vs-actual tracking through the build, you only find out whether the feasibility held at close-out, when it’s too late to do anything about it.
03 / The fix
A workflow that holds up
- 01
Build the estimate in layers
Start from the construction figure, then add site, statutory, finance, time risk and transaction costs explicitly. Don’t fold them into a single rate.
- 02
Price the site, not the average
Earthworks, retaining, services and landscaping are block-specific. Price the actual site rather than a benchmark allowance.
- 03
Include the statutory layer
Pull council and state charges, contributions and levies into the feasibility up front, because they hit before a slab is poured.
- 04
Model holding over a real duration
Carry finance and holding cost across the build time you’ll actually take, not the one you’d like to.
- 05
Carry contingency for time risk
Allow for variations, weather and trade availability so the first delay doesn’t come straight out of margin.
- 06
Track committed vs actual through the build
Check the feasibility against reality as costs commit, so you catch drift at 2%, not at close-out.
04 / The tooling
How software helps
A feasibility is only as good as the cost data behind it and only as useful as your ability to hold it through delivery. The maths isn’t the hard part. Keeping the layers complete at quote time, and keeping cost current as the job runs, is.
Software helps on both ends. Faster, more accurate estimating means the construction and site layers start from real quantities rather than a rate-of-thumb. And live cost tracking (budget vs committed vs actual) means the feasibility is checked continuously against what’s actually being spent, so drift surfaces while you can still act on it.
05 / In practice
Where VIABUILD fits
VIABUILD keeps the feasibility honest from quote to handover.
VIABUILD’s AI estimating and plan takeoff turn drawings into quantities in minutes and flow them straight into estimates, budgets and purchase orders, so the construction and site layers start from real numbers. Real-time cost tracking then shows budget vs committed vs actual across every job, with variance alerts that fire at 2%, not at close-out.
Because AI accounts payable keeps actual cost live as invoices arrive, the feasibility you quoted is checked against reality the whole way through the build, not reconstructed after the fact.
- Plan takeoff to real quantities, fast
- Quantities flow to estimates & POs
- Budget vs committed vs actual, live
- Variance alerts at 2%, not close-out
- Actual cost kept current via AI AP
- Feasibility checked through delivery
06 / FAQ
Common questions.
Construction cost benchmarks like the Cordell Construction Cost Index and Rawlinsons describe the construction line only: the per-square-metre cost of building the dwelling itself. They exclude site-specific works, statutory charges, finance and holding, time risk and transaction costs, all of which a developer or owner still has to wear to get a finished home onto a block.
Site-specific costs (earthworks, retaining, services, driveways, fencing, landscaping); the statutory layer (council and state charges, developer contributions, infrastructure levies); finance and holding costs; time risk (variations, weather, trade availability, insolvency); and back-end transaction costs (stamp duty, GST, conveyancing). Added together, these lift the all-in cost well above the headline rate.
Because the all-in cost of delivering new (construction plus site, statutory, finance, time-risk and transaction layers) has risen faster than the resale value of comparable established stock in many growth corridors. When the cost to produce a new home exceeds what the market will pay, new projects stop stacking up, which is a supply problem on the cost side of the equation.
Build the estimate in complete layers up front, model holding over a realistic build duration, carry contingency for time risk, and then track committed vs actual cost continuously through the job. Checking the feasibility against reality as costs commit lets you catch drift at 2% rather than discovering it at close-out.
About the author
Brad Caldon
Founder, VIABUILD
Brad Caldon is the founder of VIABUILD and a builder and property developer with nearly two decades across residential construction and development. He holds a NSW Home Builder Licence, is a Registered Building Practitioner across Class 1 to Class 9 buildings, and holds a Bachelor of Construction Management (Building) (Honours) from the University of Newcastle.
More about VIABUILD →07 / Keep reading
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