Custom home builders glossary
Short, plain-English definitions of the terms you'll meet when choosing a custom home builder provider in Australia-wide.
- What are progress payments in Australian building contracts?
- Progress payments are scheduled payments made during construction, released at predetermined milestones or stages of work, as specified in the building contract.
- What is a building permit?
- A building permit (or construction certificate in Australia) is the formal approval issued by a local council authority that authorises construction work to begin, certifying compliance with the National Construction Code and relevant building standards.
- What is a bushfire attack level (BAL) rating?
- A BAL rating is a classification system under Australian Standard AS3959 that measures the level of bushfire risk a property faces, determining what construction materials and building methods must be used.
- What is a certificate of occupancy?
- A certificate of occupancy is the official document issued by local councils or certifying authorities confirming a newly built home complies with building codes and is legally safe to occupy.
- What is a complying development certificate?
- A complying development certificate (CDC) is a streamlined approval pathway available in NSW for building work that meets set performance criteria, issued by a certifier as an alternative to traditional development approval.
- What is a contour survey?
- A contour survey maps the height variations and slope of a block of land using contour lines to show elevation changes, essential for designing and positioning homes on sloping or uneven terrain.
- What is a cost-plus contract?
- A cost-plus contract requires the client to reimburse the builder for all verified project costs, labour, and materials, plus an agreed percentage or fixed margin as the builder's fee.
- What is a defects liability period?
- The defects liability period is the timeframe after handover during which a builder remains responsible for repairing construction defects at no cost to the owner.
- What is a development application (DA)?
- A development application is a formal submission to your local council seeking approval to build a custom home on a property, assessing compliance with zoning, design standards, and local planning rules.
- What is a fixed price building contract?
- A fixed price building contract sets a single, agreed cost for the entire custom home project, including all labour and materials, with the builder bearing the risk of cost overruns unless the owner changes the scope.
- What is a prime cost item?
- A prime cost (PC) item is a line in a building contract that sets aside a budget allowance for materials or fixtures (such as tapware, tiles, or light fittings) that will be selected and confirmed later in the build process.
- What is a provisional sum?
- A provisional sum is an estimated amount included in a building contract for items or works whose final cost cannot be fixed at the time of quoting, such as excavation depth or selected finishes.
- What is a registered building practitioner?
- A registered building practitioner is a builder or contractor licensed and registered under state legislation to carry out building work, subject to training, insurance, and compliance requirements set by the relevant regulatory authority.
- What is an energy efficiency rating (NatHERS / 7 star)?
- A NatHERS rating is a 1-7 star measure of a home's thermal performance, showing how well it maintains comfortable temperatures without excessive heating or cooling. The 7-star standard is the current national minimum requirement for new homes in Australia.
- What is an owner-builder?
- An owner-builder is a homeowner who directly undertakes and manages the construction of their own residence, rather than engaging a licensed building contractor, and must comply with state-based owner-builder legislation and permitting requirements.
- What is cut and fill?
- Cut and fill is the excavation and redeposition of soil to create a level or stepped platform for a house foundation on sloping ground.
- What is home warranty insurance?
- Home warranty insurance is a protection scheme that covers homeowners' financial losses if a builder becomes insolvent or fails to complete residential building work as contracted.
- What is post and beam construction?
- Post and beam construction is a structural system that uses vertical posts to support horizontal beams, typically used to elevate homes above ground level on steep terrain or elevated sites.
- What is practical completion?
- Practical completion is the contractual milestone when a builder has substantially finished construction work to a standard fit for occupancy, typically triggering final payment and transfer of the home to the owner.
- What is retaining wall engineering?
- Retaining wall engineering is the structural design of walls that hold back soil on sloping sites, typically required by local council for building approval on hillside and split-level blocks.
- What is site classification in a soil report?
- Site classification is the rating system (A through P) applied to soil in Australian soil reports under AS2870 that specifies the footing depth and slab construction method needed for residential building on that site.
- What is split-level design?
- Split-level design arranges floor levels at staggered heights to conform to sloping sites, creating distinct zones without requiring full multi-storey construction or extensive earthworks.
- What is structural engineer's certification?
- Certification from a licensed structural engineer verifying that a custom home's foundation, beams, and load-bearing elements comply with Australian building codes and design specifications.
- What is the difference between slab on ground and suspended slab?
- A slab on ground is a concrete floor cast directly on compacted earth, while a suspended slab is a reinforced concrete floor supported by beams or stumps above ground, typically required on sloping or elevated sites.