Do I need a rainwater tank?
Not always. New single dwellings, secondary residences, and most extensions or alterations must meet one of three water efficiency options. For many developments, this means installing a rainwater tank, but you can also choose an approved greywater system or demonstrate a 40% reduction in mains water use.
Not always. The Planning (Residential Zones) Technical Specifications 2026 require new single dwellings, secondary residences, and most extensions or alterations to meet one of three water efficiency options:
- Option A – Rainwater tank: The required tank size depends on the block size:
- Compact blocks: No rainwater tank is required, but high-efficiency (minimum 3-star WELS) plumbing fixtures must be installed.
- Mid-sized blocks: Minimum 2,000 L rainwater tank.
- Large blocks up to 800 m²: Minimum 4,000 L rainwater tank.
- Large blocks 800 m² or greater: Minimum 5,000 L rainwater tank.
The tank must collect water from part of the roof and be connected to at least a toilet, laundry cold water, and external taps.
- Option B – Greywater system: Install a Class A treated greywater system connected to toilets, laundry cold water, and external taps.
- Option C – Water efficiency: Demonstrate that the development will reduce mains water use by at least 40% compared with an equivalent 2003 development, without relying on landscaping measures.
So, you do not always need a rainwater tank, as long as your development meets one of the other approved water efficiency options.
Reference: Planning (Residential Zones) Technical Specifications 2026 (NI2026-303), Assessment Outcome 19.5- Planning (Residential Zones) Technical Specifications 2026
Link on the answer: https://www.legislation.act.gov.au/View/ni/2026-303/current/PDF/2026-303.PDF
Where this question is kept
| Dual Occupancy Q&A | #211 | agrees | 31/07/2026 |