Introduction
Australian building contracts, plans and approvals are full of acronyms and technical terms. This glossary provides plain-English explanations of some of the most common words and phrases you will see as a homeowner.
It is a practical starting point only — always refer to your actual contract and the official guidance from regulators such as the National Construction Code (NCC), Victorian Building Authority (VBA), NSW Fair Trading and the Queensland Building and Construction Commission (QBCC).
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Core Regulatory Terms
National Construction Code (NCC):
Australia-wide code that sets minimum requirements for the design and construction of buildings, including structure, fire safety, health, amenity and energy efficiency. Published by the Australian Building Codes Board.
Australian Standards (AS):
Technical documents that provide detailed requirements for specific elements (for example slabs, timber framing, bushfire construction). Many are referenced in the NCC and in contracts (e.g. AS 2870, AS 1684, AS 3959).
Building Surveyor / Certifier:
A registered professional who issues building permits and carries out mandatory inspections to check work complies with building legislation and the NCC.
Planning Permit:
Approval from your local council about what can be built on the land (use, height, setbacks, overlays). Required in many cases before a building permit can be issued.
Building Permit:
Written approval from a building surveyor authorising work to start, confirming that the proposed building work complies with the building regulations and NCC.
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Contract and Money Terms
Prime Cost (PC) Item:
An allowance in the contract price for supply of an item (such as tiles or appliances) where the exact product has not been finalised. If you choose items above or below the allowance, the final price is adjusted.
Provisional Sum (PS):
An allowance for work where the scope and/or cost cannot be fully detailed at contract signing (for example rock removal, complex excavation). The final cost is based on actual work and agreed rates.
Variation:
Any change to the work described in the contract, plans or specifications. Variations usually affect price and/or time and should always be documented and approved in writing.
Progress Claim / Progress Payment:
An invoice from the builder for work completed to a certain stage (e.g. base, frame, lock-up, fixing, practical completion). Stages may be defined in legislation or in your contract.
Retention / Security:
Money sometimes withheld from payments (or held as a bank guarantee) to provide security that work will be completed and defects rectified. Not all domestic building contracts use retention; check your specific agreement.
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Project Stages and Quality Terms
Practical Completion (PC / PCI):
The stage when the building work is, in the builder’s opinion, complete enough for you to reasonably live in, except for minor defects or omissions that do not stop normal use. Often linked to a Practical Completion Inspection (PCI) and a progress payment.
Defects Liability Period:
Period after completion during which the builder is required under the contract to return and fix certain defects. This is separate from longer statutory warranty periods that may apply under state law.
Latent Defect:
A defect that is not reasonably visible or discoverable at practical completion (for example, issues inside walls or under slabs) but becomes apparent later.
As Constructed / As-Built Documentation:
Drawings or documents updated to show how the building was actually constructed, including changes made during construction.
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Site and Structural Terms
Slab Classification (e.g. Class M, H1, H2):
Categories under AS 2870 describing expected ground movement and the design response for slabs and footings.
Setback:
The required distance between a building and the property boundary or street, set by planning rules.
Easement:
An area of land on your title where someone else (often council or a water authority) has rights to install or access services. Building over easements is restricted.
R-Value:
Measurement of thermal resistance for insulation. Higher R-values generally mean better resistance to heat flow.
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Fire, Bushfire and Energy Terms
BAL (Bushfire Attack Level):
Rating that measures the potential bushfire exposure of a site (e.g. BAL-12.5, BAL-29). Determines additional construction requirements under AS 3959 and the NCC.
Energy Rating / NatHERS:
Assessment of the home’s thermal performance (often shown as a star rating). Required for most new homes and major renovations.
Smoke Alarm / Detector:
Life-safety devices required under the NCC and state regulations. Placement and type are regulated; your building surveyor or electrician can explain the specific rules.
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Roles and Documents
Principal Contractor / Builder:
The builder named in the domestic building contract, responsible for carrying out and coordinating the work.
Owner-Builder:
In some states, a person who takes responsibility for managing their own building work instead of engaging a registered builder. Strict rules and risks apply; check your state regulator.
Occupancy Permit / Certificate of Final Inspection:
Documents issued by the building surveyor at completion confirming that the building is suitable for occupation (or that specified work has been satisfactorily completed).
Scope of Works / Specifications:
Detailed description of the materials, fixtures and finishes to be provided. Often attached to the contract as schedules or inclusions lists.
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Where to Learn More
For deeper explanations and legal definitions:
- Australian Building Codes Board – NCC and technical resources.
- Victorian Building Authority – Victorian guidance and definitions.
- NSW Fair Trading – NSW building and contract information.
- QBCC – Queensland building guidance.
You can also search the Buildies.io Knowledge Base for articles that expand on many of the terms in this glossary.