Choosing a Hot Water System to Lift Your BASIX Energy Score
Hot water is one of the largest energy uses in a home and a major lever for BASIX. Here is how the main systems compare.
Hot water quietly accounts for a large slice of household energy, which makes it one of the most powerful levers in a BASIX and Whole-of-Home assessment. Choosing the right system can lift your energy score more than almost any other single decision.
The main options
| System | Efficiency | Notes |
|---|---|---|
| Heat pump | High | Uses ambient heat, strong BASIX performer |
| Solar hot water | High | Excellent where roof space and sun allow |
| Instantaneous gas | Moderate to high | Compact, good for small dwellings |
| Electric resistance storage | Low | Cheap to buy, weak for the score |
Why it moves the score so much
The energy assessment counts the annual energy your fixed systems use. A heat-pump or solar system delivers the same hot water for a fraction of the energy of an old electric-resistance tank, so swapping the system can turn a failing energy result into a comfortable pass without touching the rest of the design.
Matching the system to the home
- Standard family home. A heat pump is usually the best all-round choice.
- Good roof and sun. Solar hot water can be excellent.
- Compact granny flat. Instantaneous gas saves space.
- Tight upfront budget. Be cautious with electric resistance, as it can force costly upgrades elsewhere to compensate.
The hidden saving
Beyond compliance, an efficient hot water system cuts running costs for the life of the home. It is one of the rare upgrades that pays back in both the assessment and the power bill.
Frequently asked questions
Will a heat pump alone pass BASIX? It is a strong start, but the result depends on the whole design. It often does most of the heavy lifting on the energy target.
Is gas still allowed? Efficient gas systems remain an option, though all-electric homes with heat pumps and solar are increasingly favoured.
Not sure which system suits your build? Ask our assessors for advice tailored to your plans.
BASIX & NatHERS specialists, a division of Contrive Consultants. We help NSW homeowners and builders achieve energy-efficient, compliant homes.