BASIX and rainwater tanks
BASIX sets a water target for new homes in NSW. Rainwater tanks are one of several alternative water sources BASIX recognises. They aren’t automatically mandatory, but most new homes use one to meet the target. If your BASIX certificate lists a tank, it will set the minimum size, the roof area to connect and what the water is used for (for example toilets, laundry and garden), so the install needs to match it.
Check your BASIX certificate and talk to your builder or certifier about what’s required before ordering a tank.
A typical slimline setup
- ✓Slimline tank on a level base along a side wall or fence line
- ✓Downpipes from the roof area nominated on your BASIX certificate
- ✓Pump with automatic mains changeover so toilets keep working if the tank runs dry
- ✓Connection to toilets, laundry cold tap and garden taps, by a licensed plumber
- ✓Overflow connected to the stormwater system
Fitting a tank into a tight side passage
Slimline tanks are narrow enough for many side passages, and some can be linked together for more capacity. Ask the installer about access widths, the pump’s noise and position relative to bedrooms, and any council setback or height conditions.
Highlands conditions to plan for
Cold winters mean exposed pumps and pipework need frost protection. Many properties are mapped as bushfire prone, which can affect tank material and outlets. And a full tank is very heavy, so the base needs to be level and compacted. More on rainwater tanks in the Southern Highlands.
Frequently Asked Questions
Does BASIX require a rainwater tank?+
Not always. BASIX requires new homes to meet a water target, and a rainwater tank is the usual way to meet it, but your BASIX certificate is what sets the commitment. Check your certificate and with your certifier.
Can my existing tank count for BASIX?+
Generally the tank on a BASIX certificate is a new commitment for the new development, so an existing tank often can’t be used. Your certifier can confirm.
How Highlands Tank Pros works
Highlands Tank Pros is a local lead-matching service connecting Southern Highlands property owners with independent, licensed plumbers and rainwater tank installers. When you call or send a request, we pass your details to a local installer who contacts you to quote. The installer you’re matched with is responsible for the work, its pricing and any warranties.