Comparing contractor quotes by the final number is the fastest way to choose the wrong builder. The lowest price often covers the least work, and the difference only becomes clear once the project is underway.
The fix is a like-for-like comparison. This guide explains how to structure it, which exclusions to look for, and how to weigh price against evidence of competence.
Key facts
- A lump sum without a scope is not a comparable quote.
- Provisional sums are estimates and can rise.
- Check licence, insurance and references before price.
- Payment should follow completed stages, not calendar dates.
Contents
- Never compare totals alone
- Demand a written scope of works
- Check what is excluded
- Labour, materials and provisional sums
- Payment schedules and retention
- Score quotes on a like-for-like grid
Never compare totals alone
A total tells you what the builder expects to be paid, not what you will receive. Two quotes can differ by thousands because one includes electrical work, waste removal and painting while the other excludes all three.
Put the quotes side by side and map every line to the same scope. If a line is missing, ask for it in writing before comparing. Only then does the price difference mean anything. Our budget guide shows how to structure the scope in the first place.
Demand a written scope of works
The scope should list what is being built, the materials and finishes, who supplies what, and what is excluded. It should reference drawings and specifications by date so there is no ambiguity about which version is being priced.
A one-page quote is acceptable for a small repair, not for a renovation. If a builder cannot or will not write a clear scope, that is a warning about how the project will be managed.
Check what is excluded
Common exclusions include waste removal, making good, painting, appliance connection, council fees, engineering and asbestos removal. Some are reasonable; others should be in the base price. The point is to know which is which.
Ask for exclusions to be listed explicitly rather than buried in terms. A quote that says allowances apply is not fixed. Clarify the allowance amount and what happens if costs exceed it.
Labour, materials and provisional sums
Separate labour from materials so you can see the real cost of each. Ask whether materials are charged at cost plus a margin or at a fixed price, and whether GST or sales tax is included.
A provisional sum is an allowance for work that cannot be priced yet. It is not a cap. Ask what happens if the actual cost is lower or higher, and require written approval before any provisional sum is exceeded.
The cheapest quote is the one with the fewest surprises, not the smallest number.
Payment schedules and retention
Payments should follow completed stages, not the calendar. A large deposit before work starts protects the builder, not you. Agree stages, amounts and evidence of completion in the contract.
Retention is a percentage held back until defects are fixed. It is normal on larger projects. Never pay the final amount before the work is complete and the certificates have been handed over.
Score quotes on a like-for-like grid
Build a simple grid: price, scope completeness, inclusions, timeline, licence and insurance, references, and communication. Score each out of five. Price should be one column, not the whole decision.
Call two recent references and ask about timeline, cleanliness, variations and how problems were handled. Then choose the quote that offers the best overall package, not the one that is easiest to say yes to. Our renovation timeline helps you judge whether the programme is realistic.
