Buildline Renovations & Extensions 05 7 min read Guide
The new home build process from slab to handover
The nine stages of a new home build, what drives the cost, how long it takes, and the inspections that happen along the way.
Short answer: A new home build follows a clear path: site check, design, council, contract, then build in stages from slab to handover. Each stage has a sign-off point. Knowing the path means fewer surprises and better decisions.
The new build sequence
Every new home follows the same stages, whether it is a single-storey on a flat block or a split-level on a slope. The steps overlap slightly, but each one produces a clear output you review before the next begins.
The nine stages of a new home build
- Site check and soil test. We inspect the block, check access, slope, and services. A soil test (geotech report) tells us what the slab needs. This is the first cost driver.
- Design brief. We discuss rooms, layout, budget, and how you want to live. You get concept plans and a written brief to review.
- Working drawings. Full plans, sections, and specs ready for council and for pricing. The engineer sizes the slab, lintels, and bracing.
- Council approval. We lodge the DA or CDC, manage the process, and keep you posted. No work starts until this clears.
- Fixed-price contract. A line-by-line price with every finish named. No round numbers, no "PC" or "provisional" items.
- Site prep and slab. Clear, level, set out, pour. The slab is the base everything sits on. It gets inspected before the frame goes up.
- Frame, lock-up, fix-out. Frame goes up, roof on, windows and doors in (lock-up). Then internal linings, wet areas, kitchen, and fit-off.
- Practical completion. A joint walk-through. Every defect is listed and fixed before handover.
- Handover and warranty. Keys, manuals, certs, and the warranty schedule. The 6-year structural warranty starts.
How long a new build takes
These are on-site build times only. Add 3 to 6 months for design, council, and contract before the first machine hits the block.
6 to 9 mo
single-storey, flat block
Typical AU residential, 2026
8 to 12 mo
two-storey or split-level
Typical AU residential, 2026
10 to 14 mo
steep site or custom design
Typical AU residential, 2026
On-site build only. Design, council, and engineering add 3 to 6 months before the build starts.
What drives the cost of a new build
Two homes with the same floor plan can differ by 30 percent because of soil, slope, access, and finishes. Knowing what moves the price helps you compare quotes on the same terms.
The six cost drivers
- Soil class. Rock or reactive clay means a deeper slab or piers. The geotech report sets this before design starts.
- Slope. A flat block costs less than a cut-and-fill or a pier-and-beam job. Retaining walls add cost fast.
- Size and storeys. Cost per square metre drops as the house gets bigger, but a second storey adds the stair, the upper slab, and extra scaffold time.
- Finishes. The gap between a builder-grade kitchen and a stone-and-timber kitchen can be $30,000 on the same layout.
- Services. If power, water, and sewer are not at the block, the cost to bring them in can be $10,000 to $40,000.
- Council and BAL. A bushfire zone (BAL rating) adds to materials and glazing. Flood or heritage zones add to approvals.
Fixed-price vs cost-plus contracts
There are two main contract types for new homes. Knowing the difference stops you signing the wrong one.
Fixed-price contract
Cost-plus contract
Total price is locked before work starts.
You pay actual costs plus a margin. Final price is unknown.
Every finish is named in the contract.
Finishes are often left as allowances or "PC" sums.
Variations are priced and approved in writing.
Cost shifts are absorbed into the running total.
Builder carries the risk of price rises.
You carry the risk of price rises.
Red flag
A builder who quotes a round number with no line-by-line breakdown, uses
"provisional sums" for major items like the kitchen or bathroom, or will not
name the finishes before you sign.
Good sign
A builder who gives you a fixed-price contract with drawn plans, named
finishes, a soil report, and a clear council path before you commit.
Inspections during the build
A new home has mandatory hold points where a certifier inspects the work before it can be covered up. These are not optional.
Key inspection stages
- Slab. Steel, form-work, and plumbing checked before the pour.
- Frame. Timber or steel frame checked against the plans before linings go on.
- Wet areas. Waterproofing checked before tiles go down (bathrooms, laundry, balconies).
- Final. The certifier checks the finished home against the approved plans before the occupation cert is issued.
Common questions
How long does it take to build a new home?
A single-storey home on a flat block usually takes 6 to 9 months on site. A two-storey home or a sloping site adds 2 to 4 months. Design, council, and site prep come before that, so plan 12 to 18 months from first meeting to moving in.
What is the difference between a DA and a CDC?
A DA (development application) goes to council for review and takes 6 to 12 weeks. A CDC (complying development certificate) is assessed by a private certifier against set rules and takes 2 to 4 weeks. Not all sites qualify for a CDC. We check which path fits your block at the first meeting.
What is a fixed-price contract and can it change?
A fixed-price contract locks the total cost for the agreed scope. It can only change if you ask for a change (a variation) or if something is found that was not visible before work started (like rock below the slab). Each change is priced and approved in writing before work goes ahead.