Getting three renovation quotes and picking the cheapest is not how you save money. It's how you end up with a half-finished kitchen and a builder dispute.
The most expensive renovation is the one that blows out halfway through because the cheapest quote left out half the scope. This guide shows you how to compare renovation quotes the right way.
Why the bottom-line comparison fails
Builder quotes are not standardised in Australia. Two builders quoting the same job can produce documents that look completely different - one might be three pages with itemised costs, another might be a one-paragraph summary with a single number.
When you compare those two documents by their totals, you are not comparing the same job. You are comparing two different scopes of work that happen to have a dollar figure attached.
Common items that disappear from cheaper quotes:
- Waterproofing (kitchen and bathroom)
- Electrical rough-in and switchboard upgrades
- Plumbing rough-in and hot water relocation
- Demolition and skip bin hire
- Home warranty insurance (required in most states over certain thresholds)
- Site preparation and dust protection
- Project management and supervision
- Appliance installation (often quoted separately)
- Tiling to full height vs. half height
A quote that leaves these out is not cheaper. It is incomplete.
Step 1: Build a scope checklist before you read the quotes
Before you open a single quote, write down every item you expect the job to include. For a kitchen renovation, that might be:
- Demolition of existing kitchen
- Waterproofing (if near wet areas)
- Electrical: new circuits, rangehood wiring, oven circuit, GPOs
- Plumbing: sink, dishwasher, relocation if required
- Structural: any wall removal or modification
- Cabinetry supply and installation
- Benchtops supply and installation
- Splashback
- Appliances: supply vs. installation-only
- Flooring: new or match existing
- Painting: kitchen only or full repaint
- Site cleanup and skip bin
- Project management
- Home warranty insurance
Once you have this list, you can read each quote and mark each item as included, excluded, or not mentioned.
Step 2: Read for exclusions, not inclusions
Most quotes are written to highlight what is included. The dangerous information is what is excluded or simply not mentioned.
Scan each quote for an exclusions section. If there is none, that is itself a warning sign - it often means the builder has not been transparent about what they are not doing.
Pay particular attention to:
- Items listed as "by others" (meaning you need to organise them separately)
- Items listed as "provisional sum" or "PC sum" - these are estimates that will be confirmed (and often revised upward) during the job
- Items listed as "allowance" - similar to provisional sums, these are placeholders
Provisional sums and PC items can blow out significantly. A kitchen quote with a $3,000 PC sum for tiles might end up costing $6,000 if the homeowner chooses a different tile or if the quoted supplier has changed their pricing.
Step 3: Create a comparison matrix
Once you have read all three quotes against your checklist, build a simple table:
| Item | Builder A ($68k) | Builder B ($54k) | Builder C ($61k) |
|---|---|---|---|
| Demolition | Included | Included | Included |
| Waterproofing | Included | Not mentioned | Included |
| Electrical rough-in | Included | PC sum $2,400 | Included |
| Home warranty insurance | Included | Not mentioned | Included |
| Project management | Included | Not mentioned | 5% fee |
| Skip bin | Included | By others | Included |
In this example, Builder B's $54k quote is missing several items. Once you add waterproofing (typically $1,500-3,000), the electrical overage risk, home warranty insurance (1% of contract value), and a skip bin, that $54k quote becomes comparable to - or more expensive than - the $61k quote.
Step 4: Adjust for apples-to-apples comparison
After building your matrix, add the estimated cost of missing items to each quote to get an adjusted total.
A $54k quote missing $8k of items is a $62k quote. A $61k quote that includes everything is actually cheaper.
This adjusted comparison is what you should use when making your decision - not the original bottom-line figure.
Step 5: Assess the quality signals
Price tells you what a builder thinks the job is worth. It does not tell you whether they will do it well.
Things to check alongside the numbers:
- Detail of the quote: More detail generally indicates a more organised builder who has thought through the scope
- Response time: A builder who takes three weeks to get you a quote often takes three weeks to respond during the job
- Licence check: Verify the builder's licence number on your state's Building Commission website
- Insurance: Ask for a copy of their public liability and workers' compensation certificates
- References: Ask for two recent references from jobs of similar scope, and actually call them
Step 6: Ask the right questions before you decide
Before signing, send each shortlisted builder the same set of questions:
- What is explicitly excluded from this quote?
- Are there any items you have listed as provisional sums? What could cause them to vary?
- Is home warranty insurance included?
- How is project management handled - is there a dedicated site supervisor?
- What is your current lead time and estimated project duration?
- What payment schedule do you use?
The way a builder answers these questions tells you almost as much as the quote itself.
The fastest way to do this
Building a comparison matrix manually takes time, especially if the quotes are long or complex. Reno Reviewer automates the process - upload your quotes (PDF or copy-paste) and the tool builds the scope comparison, flags missing items, and generates the exact questions to ask each builder.
The free summary covers scope gaps and missing items. The full report includes the complete room-by-room, builder-by-builder matrix.