Variations: Changes to Scope, Price and Time

A small change to the house can become a much larger change to the contract

You are standing on site and realise the kitchen would work better with another power point. The supervisor says it is easy to do. You agree. Weeks later, the variation appears on the account with a price and an extension of time you did not expect.

Variations are normal in residential construction. The problem is rarely the existence of a variation. It is approving a change without understanding its full contractual effect. This guide builds on the earlier variations guide and focuses on the practical decisions a homeowner faces once construction is underway - particularly how to manage variations on site, avoid uncosted approvals and coordinate changes with your lender.

What is a variation?

A variation is a change to the work or obligations originally agreed under the building contract. An earlier guide describes the types of variation in detail; the key point for this guide is that a variation can change three things at once: what is being built, what you will pay and when the project will finish.

A variation can change three things at once: what is being built, what you will pay and when the project will finish.

Not every conversation changes the contract

You may discuss dozens of ideas with the salesperson, supervisor or trades. A conversation about moving a power point does not necessarily mean the contractual scope has been validly changed.

Check the contract for the required variation procedure and who is authorised to approve changes.

Why written variations matter

A proper written variation creates a record of the new bargain. You want to know exactly what is changing, the price adjustment, any builder's margin and the effect on the construction period.

'Just do it while you're there' can be expensive

A small design change can affect framing, engineering, cladding, electrical work, cabinetry and trade sequencing. The true cost is not always the retail difference between two products.

Ask for the price before authorising the work

Where practical, do not approve a discretionary variation without knowing the price. If the final price cannot yet be determined, understand the calculation basis and any margin or fee.

Variations can extend the construction period

A variation may require drawings, engineering, approvals, materials or rescheduling of trades. Ask what the proposed change does to the completion date as well as the price.

Some changes may arise without the owner's request

Unexpected site requirements, regulatory requirements or documentation discrepancies can create a need to change the work. The precise contractual power and pricing mechanism matter.

A builder's direction is not automatically a variation

If extra work is said to be required, ask whether it is genuinely outside the original scope, already required by the documents, correcting defective work or responding to a new condition.

The label on the document does not decide the issue.

Credits for omitted work matter too

Variations can reduce scope as well as increase it. If work is omitted, ask how the credit is calculated and understand the valuation method.

Beware variation fatigue

Ten modest variations can create a substantial budget increase. Maintain a running variation register showing the original contract price, every addition or credit and the revised contract sum.

Variations and your lender

A variation approved under the building contract is not automatically approved by your lender. Confirm both the contractual price and funding position before a significant change.

A practical variation checklist

Exact description of the change.

Drawing or specification revision.

Price increase or credit.

Builder's margin or fee.

Effect on construction period.

Effect on other work.

Approval or engineering required.

Who authorised it and when.

Whether signed as required.

Revised running contract price.

Questions to ask before signing

What does the contract define as a variation?

Who can request or approve one?

Must variations be in writing and signed?

Can the builder vary work without consent?

How are variations priced?

What margin applies?

How are credits calculated?

Can a variation extend time?

When are variation amounts paid?

The key lesson

Variations are normal in many builds. The discipline is simple: know what is changing, what it costs, what it does to time and record the agreement before work proceeds wherever practical.

Before You Sign

This guide provides general educational information for South Australian homeowners. It is not personalised legal or financial advice. Your position depends on your particular contract, lender requirements, documents and project circumstances. Before You Build is about understanding the bargain before it becomes difficult to change. A contract review can identify the obligations, risks and document inconsistencies that deserve attention before construction begins.

Before You Build. One Signature. One Chance.