Establish what changed.
A variation may begin with a client selection, revised consultant information, a different existing condition or a request to change the work. Compare the proposal to the agreed scope and current contract documents so the reason and the baseline are clear.
Ask for the drawing revision, location, description and who raised the change. Where there is a choice, request the options and the date a decision is needed.
Look at the whole impact.
A material swap may change more than the supply price. Check labour, lead times, associated trade work, access, maintenance and whether earlier work has to be changed. Record credits for any removed work and confirm the net effect on cost and programme.
For example, a late change to joinery dimensions can move electrical outlets or affect flooring. Have the affected trades review the updated information together before the change is installed.
Follow the agreed approval process.
Use the process in your contract to document the proposal and the decision. For NSW home building, consult the government guidance for written contracts and variations and obtain advice for your circumstances if needed.
Once approved, update the drawing register, procurement schedule and site instructions. Maintain a variation record that shows the status, decision date and reference. The same record helps reconcile final accounts and handover information.
Official guidance
NSW Government — contracts for residential building work