Building a new home in Australia — a complete stage-by-stage guide

Building a new home in Australia follows a predictable sequence of five construction stages, and knowing what happens at each one puts you firmly in control of your project. Most homeowners who experience problems with their build — missed defects, disputed payments, unresolved issues — can trace the root cause to not knowing what to look for or when to look for it.

How Australian residential construction is structured

Under most HIA (Housing Industry Association) and MBA (Master Builders Association) standard residential building contracts, construction is divided into five key stages. Each stage triggers a progress payment — money you release to your builder only once that stage is genuinely complete and inspected.

The five stages are:

1. Slab (base stage)
2. Frame (wall and roof frame)
3. Lock-up (enclosed, watertight shell)
4. Fixing (internal fit-out)
5. Practical completion (final handover)

The exact percentage of the total contract price payable at each stage varies between contracts and builders, but typical splits are:

Stage	Typical payment %
Deposit	5–10%
Slab	10–15%
Frame	15–20%
Lock-up	35–40%
Fixing	20–25%
Practical completion	2.5–5%

Your contract will specify the exact breakdown. Importantly, the deposit is limited by law in most states — in Queensland, the QBCC limits the deposit to 5% for contracts up to $20,000 and to 10% for contracts above that amount. NSW and Victoria have similar protections.

Pre-construction phase

Before any work begins on site, there is a pre-construction period that typically runs from contract signing to the first slab pour. During this time your builder is:

• Completing engineering plans and structural drawings
• Obtaining council development approval (DA) or a complying development certificate (CDC)
• Sourcing materials and scheduling trades
• Conducting a soil test to determine the slab type required

This phase often takes three to six months and can feel like nothing is happening. It is worth noting that your statutory warranty period (and, where applicable, your home warranty insurance cover) generally begins at practical completion, not at contract signing. The pre-construction phase is covered by your contract rather than the warranty.

What to do in pre-construction:

• Attend the pre-construction meeting and work through your checklist (colours, fixtures, selections)
• Confirm your building insurance is in place (builders should carry contract works insurance, but check your obligations)
• Identify your building inspector and book them for each stage before construction starts

Stage 1: Slab

The slab stage covers the preparation of the building pad, the installation of any required drainage, and the pouring of the concrete slab.

At slab stage your builder should have:

• Completed the earthworks and site levelling to the approved design
• Installed termite management systems (chemical barrier, physical barrier, or bait stations depending on your state and contract specification)
• Laid drainage piping and slab penetrations for plumbing
• Installed formwork and placed steel reinforcement to the engineer’s specification
• Poured, finished, and cured the concrete slab

What to inspect at slab stage

You should commission an independent building inspector before releasing the slab stage payment. Key items to check include:

• Slab dimensions — length, width, and level against the approved plans
• Reinforcement — whether bar sizes and placement match the engineering drawings (this is often visible on corners and edges during curing)
• Cover to reinforcement — edge cover is commonly inadequate; minimum 40 mm required in most cases
• Surface finish — no excessive cracking, honeycombing, or surface defects
• Drainage — all stormwater and sewer connections are in the right positions
• Termite protection — documented and inspected by a licensed operator

The slab is the foundation of everything above it. A defect here — whether it is inadequate reinforcement, incorrect dimensions, or a site level error — affects every wall, door, and window for the life of the building. Do not release this payment without an independent inspection.

Stage 2: Frame

The frame stage covers the erection of all wall frames, roof trusses, and the structural timber or steel framework of the building.

At frame stage your builder should have completed:

• All wall frames erected plumb and square
• Roof trusses and/or rafters installed and tied down
• Bracing installed to resist lateral loads (wind bracing)
• Lintels over all openings (windows, doors, garage openings)
• Window and door frames set into openings

What to inspect at frame stage

Frame inspections are critically important because the frame will be covered by linings, and many defects become latent once the walls are lined. A building inspector can check:

• Plumb and square — whether walls are vertical and corners are right-angled
• Bracing panels — correct number, placement, and fixings per the engineer’s specification
• Truss connections — gang-nail plates, tie-downs to top plates, and ridge connections
• Lintel sizes — adequacy of lintels over openings; undersized lintels deflect over time
• Stud spacing — whether stud centres match the engineering specification
• Noggings — presence and correct installation of horizontal noggings between studs
• Timber species and grade — whether the framing timber matches the specification

The National Construction Code (NCC) and Australian Standard AS 1684 govern residential timber framing in Australia. Deviations from these standards at frame stage are a legitimate basis for withholding the stage payment.

Stage 3: Lock-up

Lock-up is one of the largest payments in the schedule and marks the point at which the building becomes a closed, weather-resistant shell. By lock-up, the following should be complete:

• External wall cladding (brickwork, weatherboard, fibre cement, or other specified cladding)
• Roof covering (tiles, Colorbond, or other roofing)
• Windows installed and glazed
• External doors hung and lockable
• Garage doors installed

This stage is called “lock-up” because the building is now lockable — it can be secured against the weather and unauthorised entry.

What to inspect at lock-up

Lock-up inspections are particularly important for waterproofing and weatherproofing. Key inspection points:

• Roof — all tiles or sheets in place, hip and ridge cappings sealed, no cracked or damaged roofing, correct fall on all surfaces
• Flashings — around all roof penetrations (vents, exhaust flues, valleys), at window and door heads, and at any junction between the roof and a wall
• Cladding — correct laps on weatherboard or fibre cement, no cracking in brickwork, weep holes present in brick veneer construction
• Window installation — sill flashings in place, all window seals complete, no gaps at reveals
• Waterproofing to wet areas — before tiles are laid, wet areas (bathrooms, laundries, ensuites) must be waterproofed. Waterproofing should be inspected and passes a flood test before tiling begins

Lock-up is also when your electrical and plumbing rough-in should be largely complete. While you cannot see the pipe and wire work inside walls, you can check that rough-in penetrations are in the correct locations per the electrical and hydraulic plans.

Stage 4: Fixing

The fixing stage (sometimes called the fit-out stage) covers all internal works — the fitting out of the interior from plasterboard through to fixtures and finishes. By the fixing stage, the following should be complete or substantially complete:

• Plasterboard lined and set (taped, jointed, and sanded)
• Internal doors hung and hardware fitted
• Kitchen and bathroom cabinetry installed
• Tiling complete (wet areas, floor areas)
• Internal painting — first and second coats
• Skirting boards, architraves, and internal mouldings
• Electrical and plumbing fit-off (switches, power points, taps, basins)

What to inspect at fixing stage

This stage is the best opportunity to identify defects in trades work before the final clean and handover. Look carefully at:

• Tiling — tap each tile for hollow sound (hollow tiles indicate loss of adhesion), check grout consistency and colour, check for cracked tiles and chipped edges
• Plastering — look for joins visible in certain lighting, gaps at cornices, nail pops, and any surface damage
• Cabinetry — alignment of doors and drawer fronts, quality of mitre cuts, presence of all hardware
• Paint — runs, missed areas, inconsistent sheen, and coverage over patches
• Fixtures — all power points, switches, and light fittings in correct locations; taps for correct hot/cold orientation
• Door operation — every door should open and close without binding, striking the frame, or showing visible twist

Do not release the fixing stage payment if tiling is incomplete, painting has not received its final coat, or significant fit-off items are outstanding.

Stage 5: Practical completion

Practical completion is the formal conclusion of the build and the point at which you take possession of your new home. Under most HIA and MBA contracts, practical completion is when the works are complete to the standard required by the contract, minor defects and omissions excepted.

This stage includes the practical completion inspection (PCI) — your formal opportunity to walk through the property, document any remaining defects and omissions, and provide a written list to your builder before signing the certificate of practical completion.

You have the right under most contracts and under state legislation to be accompanied by an independent building inspector at the PCI. Use that right. A qualified inspector typically costs $300–$600 and will find issues you would otherwise miss.

What happens after practical completion

Once you accept practical completion and move in, two things happen:

1. The defects liability period (DLP) begins. This is typically 13 weeks under HIA contracts, during which you can report minor defects for rectification. Some states have longer minimum DLP periods — in Queensland, the minimum is 12 months.

2. The statutory warranty period begins. This varies by state but generally provides six to seven years for major defects and two years for minor defects.

Keep a running defects list from the day you move in. Anything that appears within the DLP should be notified in writing to your builder. Defects that emerge after the DLP but within the statutory warranty period can still be claimed — you do not forfeit your rights by missing the DLP.

Managing payments and disputes

The critical rule for progress payments: do not release a payment until the stage is complete and inspected. Once money is paid it is effectively gone — most contract disputes arise when homeowners pay early and then find themselves without leverage to get outstanding work completed.

If your builder is pressuring you to pay before a stage is complete:

1. Check your contract — progress payments are due when the stage is “complete” per the contract, not on demand
2. Seek written clarification of what is outstanding
3. Contact your state building authority if pressure continues:
   • Queensland: QBCC (Queensland Building and Construction Commission)
   • NSW: NSW Fair Trading
   • Victoria: DBDRV (Domestic Building Dispute Resolution Victoria)
   • South Australia: CBS (Consumer and Business Services)
   • Western Australia: Building Commission WA
   • Tasmania: CBOS (Consumer, Building and Occupational Services)
   • ACT: Access Canberra

The role of independent inspections

The single most effective thing you can do at each stage is commission an independent building inspector. Not your builder’s certifier — an independent inspector you have engaged yourself, with no financial relationship with your builder.

A qualified inspector brings:

• Knowledge of the NCC and Australian Standards that apply at each stage
• Professional indemnity insurance backing their findings
• A written report you can use as evidence if a dispute arises
• Identification of latent defects that are not visible after the following stage of work is complete

Independent inspections typically cost $200–$500 per stage. Given that a single missed defect can cost thousands to rectify after the fact (and may not be rectifiable without demolishing work), this is the best money you spend in the build.

Key Takeaways

• Australian residential construction follows five standard stages: slab, frame, lock-up, fixing, and practical completion — each triggering a progress payment
• Your deposit is capped by law in most states (commonly 5–10%); do not pay more than your contract specifies
• Commission an independent inspector at every stage before releasing a payment — frame and lock-up inspections are most critical
• Do not release any stage payment until the work is genuinely complete and in compliance with the NCC and your contract specification
• The defects liability period starts at practical completion; the statutory warranty (six to seven years for major defects) starts at the same time
• Keep a written, dated defect record from the day construction begins — it becomes your evidence base if the matter escalates to tribunal