.jpg)
How to Compare Builder and Trade Quotes Like a Pro (Free Tool)
The cheapest quote is often the most expensive decision
Every owner builder ends up with a stack of quotes and one tempting shortcut: pick the lowest number. But the number at the bottom of the page only means something if every quote covers the same work, the same materials and the same terms — and they almost never do. The most expensive decisions owner builders make usually start with a quote that looked cheap because something was missing.
Before you compare anything: the same-scope rule
A quote can only be compared against your documented scope — your approved drawings, specifications and a clear written description of the work. If one trade priced off different drawings or different assumptions, the comparison is meaningless. Fix that first: send every trade the same documents, and note on each quote which documents it was based on.
What to actually compare
Credentials — licence or registration number provided and verified, and public liability insurance sighted. In WA you can check registrations through Building and Energy and the relevant licensing bodies for electrical and plumbing work.
Inclusions and exclusions — are materials specified by brand and grade? Are exclusions listed clearly, or hidden behind vague lines like "all plumbing works"? Watch especially for items every other quote includes that one quietly leaves out.
Price structure — GST shown correctly, provisional sums and prime cost items itemised and realistic, and no comparing a GST-inclusive quote against an exclusive one.
Payment terms — a fair payment schedule follows the work. Large deposits before anything happens, or payments that run ahead of completed work, shift all the risk onto you.
Timing — when can they start, how long will it take, and what do they need finished before they begin?
Terms and aftercare — warranty offered, a written variations process, a written contract, and references you can actually check.
The red flags worth a second look
One red flag deserves a conversation; several deserve a different trade. The classics: a price significantly cheaper than the rest with no explanation, cash-only or reluctance to put anything in writing, pressure to sign because the "price is only valid today", and provisional sums that look too low to be real.
A free tool that does the side-by-side for you
Our free Quote Comparison tool lines up to three quotes side by side across credentials, price, scope, timing and terms — so gaps and red flags show up before you commit, not after.
How to use it
Enter each quote's details — business, licence, insurance, price and payment terms.
Work through inclusions, exclusions and timing so differences in scope become visible instead of buried.
Check the red flags and note any explanations the trade gives you.
Generate your comparison report and keep it in your project file with the quotes themselves — a documented reason beats a memory if anything is ever disputed.
Frequently asked questions
Should I always get three quotes?
Three is a sensible target for significant trade packages because it shows you the market range — one quote tells you a price, three tell you a pattern. For small jobs, two may be enough; for big packages, the time spent getting a third quote is rarely wasted.
Is the cheapest quote ever the right choice?
Sometimes — when it covers the same scope, the credentials check out and the terms are fair. The point isn't to avoid cheap quotes; it's to know why a quote is cheap before you accept it.
Is the Quote Comparison tool free?
Yes — free, no sign-up, no account. It's part of our free owner builder tools suite.
Quotes sorted? Keep going
Comparing quotes well is one skill of many an owner builder needs. Our WA Owner Builder Course covers the full journey — approvals, contracts, managing trades, payments and handover — with a complete Professional Toolkit included with enrolment.
This article is general information for owner builder education. It does not replace legal, contractual or professional advice. Confirm licensing requirements with Building and Energy (WA) and the relevant licensing bodies, and have contracts reviewed before signing where in doubt.
Comments