DIY Home Energy Audit: Find Where Your Home Wastes Energy
Most Australian households can cut their energy bills by 5–30% through small changes — and you can find those opportunities yourself with no special equipment.
A home energy audit is a systematic check of where your home loses energy and where inefficiencies cost you money. A DIY version relies on your senses rather than specialised equipment. The payoff — identifying changes that cut bills by 5–30% — is real and achievable for almost any household.
What You'll Need
| Tool | Purpose |
|---|---|
| Torch | Inspect ceiling cavity, roof space, under-floor access, behind appliances |
| Damp hand or incense stick | Detect air drafts near windows, door frames and power outlets |
| Pen and paper or phone | Note problem areas and appliance ages |
| Utility bills (12 months) | Spot seasonal efficiency drops and benchmark usage |
1. Air Leaks
Air sealing is one of the highest-return interventions in Australian homes, particularly in southern states. Draught sealing and insulation can reduce energy costs by 10–15% per year in a typical Melbourne or Canberra home.
- Check door frames for daylight gaps or drafts — use a damp hand on cold days
- Check power outlets on external walls for cold air infiltration
- Inspect the ceiling manhole — a poorly fitted hatch loses significant heat in winter
- Feel around window sashes and check if weatherstripping is intact
- Inspect pipe and cable penetrations through external walls and ceilings
2. Insulation
Homes built before 2005 in southern states often have inadequate or no ceiling insulation. NCC 2022 recommends a minimum of R3.5–R5.0 in the ceiling depending on climate zone. Check your ceiling cavity — insulation should cover the ceiling evenly to the edges without gaps.
3. Lighting and Standby Power
- LED bulbs use 75% less energy than halogen equivalents — replace any remaining halogens
- Standby power (TVs, gaming consoles, phone chargers, microwaves) can account for 5–10% of a household bill
- Smart power strips or individual smart plugs let you cut standby at the source
4. Hot Water System
Hot water is typically the second largest energy cost in an Australian home after space heating and cooling. If your storage hot water system exterior feels warm, it is losing energy through the tank walls — a sign that upgrading to a heat pump hot water system could cut this bill by 60–75%.
5. HVAC and Ducts
- Check and replace dirty air filters — a clogged filter forces the system to work harder
- Feel around duct joints in the roof space while the system is running for escaping air
- Consider a professional duct seal — leaky ducts can waste 20–30% of conditioned air
| Problem area | Detection method | DIY fix |
|---|---|---|
| Window/door drafts | Damp hand, daylight gaps | Weatherstripping and draught seals |
| Ceiling manhole | Cold draft from hatch | Insulated manhole cover or sealant tape |
| Hot water tank loss | Warm exterior surface | Heat pump replacement or tank blanket |
| Standby power | Devices warm when "off" | Smart strip or power board with switches |
| Halogen downlights | Hot to touch, ceiling holes | Replace with sealed LED downlights |
If you smell gas, see scorched wiring near your switchboard or find asbestos-containing materials in older homes, stop and call a professional immediately. A DIY audit has limits.