Two quotes are only comparable if they describe the same work. A lower total can reflect a different specification, an omitted task or an allowance that will be adjusted later. Make scope differences visible before deciding what represents value.

Send one consistent brief

Give each business the same drawing revision, written scope and schedule of selections where available. Ask them to identify assumptions and exclusions explicitly. If the brief changes, share the updated version with everyone still quoting.

Use a comparison sheet

  • Included work: demolition, preparation, construction, finishes and making good.
  • Allowances: which amounts are estimates, what they cover and how actual costs are treated.
  • Other costs: design, engineering, approvals, inspections, disposal and access arrangements.
  • Delivery: proposed start window, duration, supervision and communication.
  • Change process: how additional scope, price and time will be documented.

Keep a separate uncertainty budget

Discuss a contingency with your project team based on the condition of the property and how much remains unknown. Do not treat an illustrative percentage from the internet as a reliable project estimate. Keep a record of which assumptions have actually been investigated.

Resolve questions before signing

Ask for unclear items to be clarified in writing. Read the contract and obtain independent advice on terms you do not understand. NSW guidance explains written contracts and variations; use it alongside your own documents, not in place of them. Avoid making an instruction on site before its cost and time consequences have been properly addressed.

Official sources & further reading

Sources checked 5 November 2026. Our wording and structure are original. The linked authorities provide the current requirements.

Explore specialist websites