What Counts as a Variation on a Building Job — and Why Verbal Approval Gets Messy
Updated: Sep 4
A small change on site can turn into a big argument later if nobody is quite sure what was actually agreed.
G’day, it’s Dazza. Variations are one of those building-job words that sound more complicated than they need to be.
At the practical level, a variation is a change to what was already agreed. The owner wants a different finish. A wall moves. Another power point gets added. A product changes. Something in the plans or specifications needs adjusting. The original job has changed, so the scope, price, timing — or all three — may change with it.
The trouble usually isn’t recognising that something changed. The trouble starts when the change is handled with a quick conversation on site and everyone walks away remembering a slightly different version of it.
“Yep, just do it” is not much of a record
Picture a fairly ordinary moment. The client is standing in the doorway while the job is moving. They ask whether something can be changed. The builder or tradie explains there will be a bit more work. The client says, “Yep, that’s fine — just do it.”
At that moment, everybody may genuinely believe they agree.
A week later the invoice arrives and the questions start. How much extra did we agree to? Was that price including materials? Did the change add another day? Was that particular finish part of the change, or was it already included?
Nobody necessarily did anything dishonest. The conversation simply wasn’t detailed enough to survive a week of other jobs, phone calls and decisions.
What actually counts as a variation?
The exact legal position depends on the type of work, the contract and the state or territory, so this isn’t legal advice. But a useful practical test is simple: compare what is now being asked for with what the signed scope, plans and specifications originally required.
If the work, materials, design, quantity, location or agreed outcome changes, you should at least stop and ask whether you are dealing with a variation rather than treating it as an informal favour.
That matters in both directions. An owner asking for an upgrade can change the cost. A builder discovering a genuine issue can change what is required. But extra cost is not automatically justified simply because extra work appears — responsibility for the cause and the contract terms still matter.
The rules are more formal than the site conversation
For residential building work, variation rules are not identical across Australia. In NSW, current government guidance says variations to home building contracts must be in writing, attached to the contract and signed by both parties, with the cost implications explained. In Victoria, major domestic building contracts also have formal written-variation requirements, although there are limited exceptions.
So the safe lesson is not “a verbal yes is good enough”. It is the opposite: check the contract and the rules that apply to the job, and get the change properly recorded before relying on it.
If there is any doubt about contractual rights or whether a particular variation can be charged, that is the point to get appropriate professional advice rather than guessing from a general article.
A useful record answers the boring questions
A good variation record does not need to turn a five-minute site decision into a novel. It does need enough information that somebody who was not standing there can understand the change later.
What was originally included? What is changing? Why is it changing? What does it add or remove from the price? Does it affect timing? Who agreed to it, and when? Are there drawings, specifications or photos that make the change clear?
Those questions sound obvious while everyone is looking at the job. They become surprisingly difficult once the work is covered up and the people involved are relying on memory.
Photos help — but they don’t replace the agreement
A photo can be excellent evidence of site conditions or the work completed. What it usually cannot tell you by itself is why the work changed, what price was discussed or whether the person with authority actually agreed to it.
The strongest practical record joins the pieces together: the change, the reason, the commercial effect, the approval and any supporting evidence.
That is much more useful than having a photo in one phone, a text message in another and a handwritten note saying “extra $450?” sitting in the ute.
This is exactly the sort of friction worth removing
I’m looking closely at variation approval as one of the small trade workflows Dazza can make simpler. The aim isn’t to replace the building contract or pretend software can decide somebody’s legal rights. It is to make the practical record easier to create while the conversation and the job are still fresh.
That work is still being developed, so I’m not suggesting there is a finished Dazza tool ready to use today.
But the problem is clear enough already: if a change matters to the scope, price or finish of a job, it deserves a better record than “I’m pretty sure we talked about that on Tuesday”.
Get the change clear. Get the right approval. Keep the record with the job. That is a much easier conversation to have before the work starts than after the invoice lands.
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