Sustainability gets sold as a premium upgrade. In reality, four of the five highest-impact moves pay for themselves through energy bills inside five years on a typical Melbourne home.
1. Wall and underfloor insulation
If you've got walls open during a renovation, insulating them is the single highest-ROI move available. Payback is usually 2–4 years on the gas and electric saved.
2. Double glazing on the worst-facing windows
You don't need to do every window — west and south windows on living areas deliver most of the comfort improvement. Payback inside 5 years on a typical period home.
3. Heat-pump hot water
Replaces a gas storage unit. Federal and state rebates currently bring the upfront cost close to like-for-like, with running costs roughly a third of gas. Payback often inside 2 years with rebates.
4. Induction cooktop
Cheaper to run than gas, faster to cook on, and removes a combustion source from the kitchen. Pays back the marginal cost over a gas alternative inside 3–4 years.
5. The one that doesn't always pay back
Solar PV without a battery still pays back well — usually 4–6 years. Adding a battery often doesn't pay back inside 10. Worth knowing before you commit.
