Cost Plus
By George Giannakakis · M.Arch · RLA300580 · HIA Industry Judge
Last reviewed: · How we research
Cost Plus explained in detail
This is a pricing method where the builder charges labour and materials at cost, with an additional fee (margin) for project management services and administration. The owner pays the actual cost of the build plus the builder's agreed margin (typically 10-20%). This method offers transparency but less budget certainty.
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Frequently Asked Questions
Common questions about cost plus
It depends on your project. Fixed price (lump sum) gives budget certainty but builders add contingencies for risk. Cost plus can be cheaper if all goes well, offers full transparency, and suits complex or custom builds. However, it requires trust in your builder and can blow out if not managed carefully.
Contract and legal information
Building contracts, dispute resolution, and consumer law are complex and vary by state and contract type. The information here is general in nature and may not apply to your situation. For advice about your specific contract, rights, or dispute, speak with a building lawyer, your state’s consumer protection body, or a licensed building consultant.
Cost figures are indicative onlyUpdated February 2026
All prices and cost ranges mentioned are approximate, based on Adelaide market conditions at time of writing, and may not reflect current pricing. Actual costs depend on your specific site, design, builder, materials, and market conditions. Project-specific quotes from qualified professionals are needed for accurate pricing.
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Verify against the binding rules in your state
BuildPilot is an independent home-build CoPilot - we publish guidance, we don't hold a building licence. Every Australian residential build must comply with the National Construction Code plus state-specific Acts and consumer-protection law. The authorities below are the primary sources of truth for the rules that actually apply to your project.
National
The primary national set of technical building standards that every Australian build must comply with. Volume 2 covers Class 1 & 10 buildings (most homes).
Specific material, product and method standards (e.g. AS 3700 masonry, AS 1684 timber framing) referenced by the NCC.
National peak body for residential builders. Publishes the most widely used home-building contracts and consumer guidance.
National peak body for general builders. Publishes commercial and residential contracts and industry guidance.
By state & territory
Links above open the public website of each authority. BuildPilot is not affiliated with these bodies and does not act on their behalf. Information on this page is general - check the current edition of the NCC and the relevant state Act for binding requirements.
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