A vacant-land build typically requires a team of around 8–14 professionals across due diligence, design and construction. Picking the right individuals matters; engaging them in the right order matters at least as much. The reason custom builds run over budget is rarely that the team was unqualified — it's that the wrong person was engaged at the wrong time, or that nobody coordinated their findings.

The team and the credentials.

  • Architect: registered with the relevant state Architects Registration Board; member of the Australian Institute of Architects (AIA). May only use the title "Architect" if registered. Fees typically 8–15% of construction cost.
  • Building designer: regulated in Victoria, Queensland and Tasmania; member of the Building Designers Association of Australia (BDAA) in other states. Fees typically 3–7% of construction cost. Cannot use the title "Architect" unless registered as one.
  • Town planner: Planning Institute of Australia (PIA), with RPIA or CPP credentials. Engage if the lot needs a contested DA, a planning proposal, or has tricky zoning or overlay issues.
  • Registered surveyor: licensed by the state surveyors board (BOSSI in NSW, Surveyors Registration Board of Victoria, SBQ in Queensland, and equivalents elsewhere). Only a registered surveyor can lawfully redefine a boundary.
  • Structural, civil and hydraulic engineer: Chartered Professional Engineer (CPEng) on the National Engineering Register through Engineers Australia. RPEQ in Queensland. Victoria has a separate Professional Engineers Registration scheme. NSW additionally has Design Practitioner registration under the Design and Building Practitioners Act 2020.
  • Geotechnical engineer: same accreditation pathway with geotech endorsement, ideally a member of the Australian Geomechanics Society.
  • Bushfire consultant: BPAD accreditation through the Fire Protection Association Australia (Level 1, 2 or 3 depending on site complexity).
  • Consulting arborist: AQF Level 5 minimum (Diploma of Arboriculture). Members of Arboriculture Australia or the Institute of Australian Consulting Arboriculturists.
  • NatHERS thermal performance assessor / BASIX consultant: accredited through one of three NatHERS-approved bodies — Design Matters National, ABSA, or HIA.
  • Building certifier or building surveyor: state-by-state. Registered with the NSW Building Commission, Building and Plumbing Commission in Victoria (which took over from the VBA on 1 July 2025), QBCC in Queensland, and equivalents elsewhere.
  • Quantity surveyor: AIQS member (MAIQS, FAIQS). Used for pre-contract feasibility, tender review and depreciation schedules.
  • Conveyancer or property solicitor: state-licensed. Conveyancers handle routine Torrens transactions; solicitors are essential for anything unusual.
  • Buyer's agent (optional): REBAA member.
  • Builder: licensed under each state's licensing scheme (NSW Fair Trading, VBA/BPC, QBCC, Building & Energy WA, CBS SA, CBOS Tasmania, Access Canberra, NT Building Practitioners Board).

Engaging the team in the right order. The optimal sequence:

  1. Pre-purchase (before unconditional contract): conveyancer or solicitor for contract review, town planner for an advice call, registered surveyor for an identification or feature survey, geotechnical investigation, BPAD assessor if the lot is bushfire-prone, arborist if significant trees are present, and a contamination consultant if any PSI risk is flagged.
  2. Design phase (post-settlement): architect or building designer as lead consultant, structural engineer, civil and hydraulic engineer for stormwater and OSD, BASIX or NatHERS assessor, surveyor returning for set-out and detailed contour.
  3. Certifier engagement before DA lodgement or alongside it.
  4. Builder engagement under one of three models — design-only / traditional tendering after full documentation; design-and-construct (D&C) with a project home or D&C builder selected first; or early contractor involvement (ECI) where a builder is brought in during design to advise on buildability and cost.

Contract types. Most residential work uses lump-sum / fixed-price contracts — the builder commits to a sum subject to provisional sums (estimates for undefined works), prime cost items (allowances for unselected products) and variations. The risk is that the headline price gets eroded by PS and PC overruns; minimising those before signing is the most important thing a buyer can do. Cost-plus contracts (builder bills actual cost plus a margin) shift cost risk to the owner — useful for very complex custom builds, risky for inexperienced owners. Construction management (owner contracts trades directly via a CM) is rare for residential. Design and construct is single-point accountability but limits design flexibility.

Three standard form contracts dominate. HIA contracts (Housing Industry Association) are widely used and considered builder-favourable. Master Builders state association contracts are similar. ABIC contracts (Australian Building Industry Contracts, a joint AIA / Master Builders Australia publication) are widely considered the most balanced — they're commonly used for architect-administered residential and small commercial work.

Statutory home warranty and domestic building insurance vary by state:

  • NSW: Home Building Compensation Fund (HBCF) via icare, work over $20,000, $340,000 minimum cover.
  • VIC: Domestic Building Insurance via the Building & Plumbing Commission (from 1 July 2025; previously VMIA), work over $16,000, $300,000 cover.
  • QLD: Queensland Home Warranty Scheme via QBCC, work over $3,300, $200,000 cover.
  • WA: Home Indemnity Insurance through the private market, work over $20,000, $100,000 typical cover.
  • SA: Building Indemnity Insurance via SAFA, work over $20,000 (raised from $12,000 in November 2025), $250,000 cover (raised from $150,000 in October 2025).
  • TAS: statutory warranty under the Residential Building Work Contracts Act 2016.
  • ACT: Builders Warranty Insurance under the Building Act 2004, work over $12,000.
  • NT: no mandatory home-warranty scheme.

The schemes generally cover only catastrophic events — builder death, disappearance or insolvency. They are not a defence against poor workmanship or contract disputes. The absence of a mandatory scheme in NT, and the limited coverage in WA, mean buyers there should be especially diligent about builder financial stability.

Tendering and selecting a builder. Industry guidance recommends three to four builders tendering identical documents — architectural drawings, specifications, schedule of inclusions and finishes, list of PC and PS items with allowances, geotechnical report, BAL assessment, civil drawings. Score on contract sum, number and quantum of PS items, PC allowance levels, stated program, inclusions and exclusions, builder margin on variations, and liquidated damages rate.

Red flags in tender responses: a quote materially below the others (often 10–15% below — usually means missing scope); vague or unitemised PS or PC allowances; long lists of exclusions buried in clauses; refusal to use ABIC or a balanced form; deposit above the statutory maximum (5–10% depending on state); no detailed program; high percentage of contract claimed at base or frame stage.

Check before you sign. Verify licence currency through the relevant state register. Check ASIC's insolvency notices register — directors of recently-failed building companies sometimes reappear under new entities. Request a current Letter of Eligibility from the builder's home warranty insurer (in WA, VIC and SA, this is a meaningful signal of solvency). Visit at least two completed projects, including one three to five years old. Domestic-builder insolvency in Australia has been a persistent issue through 2023–2025 — always plan as if the builder may not be there at handover.

Questions worth asking each professional:

  • Architect or designer: How many similar projects in the last 3 years? Fee structure and basis? What software and deliverables do I receive at each stage? Will you administer the contract through construction, and at what fee?
  • Surveyor: Turnaround time? Deliverables and formats? Are feature surveys (trees, services, kerb invert levels) included by default?
  • Geotech: Number of boreholes and depth? AS 2870 classification only, or also shrink-swell index? Reactive-soil testing on H1/H2/E sites?
  • Bushfire (BPAD) consultant: Accreditation level? Will you do both the BAL assessment and the Bushfire Attack Level report for council?
  • Builder: Current licence and Letter of Eligibility for warranty insurance? Variation rate on the last ten similar projects? Site cost assumptions about soil, slope and BAL? Which contract form will you use? Payment schedule and deposit percentage? Default supplier credit terms?

Red flags in any professional: unwillingness to provide a written scope; verbal-only promises; no professional indemnity insurance; cash-discount offers; reluctance to provide references; refusal to use a balanced standard form; deposit above statutory maximum; aggressive sales tactics.

The team is, in many ways, the project. A great team can rescue a difficult lot. A weak team can ruin a perfect one. Spend more time on team selection than on house design — by the time the design is done, the team is what will deliver it.

This article is general information only — a starting point for your own questions, not legal, financial or contractual advice. Building licensing, statutory warranties and contract law vary by state and territory, and recent regulatory changes (notably in Victoria, SA, Queensland and WA) mean the position can change without much notice. Always engage a property solicitor to review any building contract, verify all licences and insurances through the relevant state register, and seek independent advice before signing. Independent advice should be obtained before making any property decision.

---

End of the series. Across twenty-two posts, this series has covered the paper trail from title to occupation, the technical reports that describe what's actually on the land, the design rules and physical constraints that determine what can be built, and the financial and team-selection decisions that determine whether the build succeeds. Read any post in isolation as a primer; read the full series as a roadmap. Every post should send you to qualified independent professionals — not as a hurdle, but as the way Australian property decisions are made well.