That depends on the size, condition, and compliance of your current system.

If your septic tank has sufficient capacity and meets current council regulations, it may be suitable for reuse. However, if it is outdated, undersized, or fails compliance checks, your council may require:

An upgrade or expansion

A completely new system

An additional absorption field or treatment area

This is typically flagged in the Prelim or finalised during your Site Assessment, but a formal wastewater assessment report is often required for council approval. This report is arranged through your builder or certifier and carries a separate fee, not covered by the standard Site Assessment cost.