How to Avoid Costly Variations
Variations are the number one cause of budget blowouts in Australian construction. Here's how to protect yourself.
What Is a Variation?
A variation is any change to the agreed scope, plans, or specifications after the contract is signed. Builders are legally entitled to charge for variations — and the costs can be significant. Studies show variations add an average of 10–20% to residential building costs.
Finalise Your Plans Before Signing
The most effective way to avoid variations is to have fully documented, council-approved architectural plans and specifications before signing a contract. Changes to plans mid-build are the biggest source of variations. Invest in design upfront.
Specify Everything in the Contract
Every material, fitting, and finish should be specified by brand, model, and colour in the contract documentation. Avoid vague descriptions like "quality tiles" or "standard vanity." These become disputes when the builder's definition differs from yours.
Scrutinise PC Allowances
Provisional Cost (PC) allowances are the builder's estimate for items not yet selected (like kitchen appliances or tiles). If allowances are unrealistically low, you'll exceed them — and pay the difference. Research real costs before signing.
Manage Provisional Sums Carefully
Provisional Sums cover work that can't be priced accurately upfront (like rock removal or difficult excavation). Ask the builder how provisional sums were calculated and insist on regular reporting against them during construction.
Never Agree to Verbal Changes
Only ever agree to variations in writing. A signed variation order with a clear description and price must precede any changed work. "We'll sort it out later" is not acceptable — and is legally unenforceable.
Freeze Your Selections Early
Late selections or changes to finishes (different tiles, upgraded appliances, extra powerpoints) are legitimate variations. Make all your selections before the contract is signed, or have a clear agreed process for late selections.