Why Is My Electricity Bill So High? A Room-by-Room Energy Audit You Can Do Today

First: is your bill actually high?

Before you tear up the floorboards, check the numbers. The average Australian home uses around 16 kWh per day, though this varies a lot by climate zone and household size.

• • 1–2 person home: 8–14 kWh/day
• • 3–4 person home: 14–22 kWh/day
• • 5+ person home (or pool / ducted aircon): 22–40+ kWh/day

Open your bill, find the daily average kWh, and compare. If you're well above the band for your household size, the rooms below are where the leak almost always is. For a deeper benchmark, see our breakdown of electricity costs across Australia.

Room 1: The roof cavity

Up to 35% of heat loss in winter (and the same again in summer gain) goes through the ceiling. This is the highest-leverage room in the house — and most homeowners never check it.

What to check:

• • Pop the manhole and look. Is there insulation? How thick?
• • Modern Australian standards aim for R5.0–R6.0 in ceilings (roughly 220–280 mm thick).
• • Check for gaps, compressed batts, or insulation pulled away around downlights.
• • Recessed halogen downlights are usually surrounded by gaps — each one is a small chimney.

The fix: Topping up ceiling insulation typically costs $1,500–$3,500 and pays back in 3–5 years on heating and cooling savings alone. Find a pro in our insulation directory.

Room 2: Living areas — windows and draughts

Single-glazed windows lose around 10 times more heat than a well-insulated wall. They are usually the second biggest reason your heater runs all evening.

What to check:

• • Tap the glass — single pane sounds different from double. Look at the frame edge for two layers.
• • On a windy day, hold a tissue or incense stick around window and door seals. Movement = leak.
• • Check the bottom of external doors. If you can see daylight, that's a 5–10 mm gap running the full width.
• • Old aluminium frames without thermal break are notorious heat conductors.

The fix order: draught seals first (under $200, DIY in a weekend), then heavy curtains with pelmets, then double glazing or secondary glazing as the bigger investment. See certified pros in our windows & glazing directory.

Room 3: Hallways, ducts and the heating system

Ducted gas or electric heating that's 10+ years old can be running at 60–70% efficiency, with another 20–30% of heat lost in the ductwork itself before it reaches the room.

What to check:

• • Age of the unit (label inside the cabinet). Anything 12+ years old is a candidate for replacement.
• • Are you heating rooms you don't use? Zoning can cut runtime by 30%.
• • Check duct joins in the roof for tape that's failed — common after 10 years.
• • Is the thermostat set above 21°C? Each extra degree adds ~10% to heating cost.

The fix: A modern reverse-cycle split or zoned ducted system runs 3–5× more efficiently than resistive electric or old ducted gas. Browse HVAC installers for quotes.

Room 4: Bathroom and laundry — hot water

Hot water is roughly 21% of household energy use and is dominated by one decision: what kind of system you have.

What to check:

• • Type of system: electric resistive, gas storage, gas instant, heat pump or solar.
• • Age — most tanks last 10–15 years; older units lose efficiency rapidly.
• • Bathroom and kitchen exhaust fans without sealed dampers vent your heated air outside 24/7.
• • Showerheads above 9 L/min. Switching to 6 L WELS-rated heads cuts hot-water use by ~30%.

The fix: A heat-pump hot water system uses ~70% less electricity than an electric resistive tank, and large state and federal rebates apply. See our hot water directory and rebate guide.

Room 5: Kitchen and living — appliances & standby

Standby power is ~7% of a typical bill — small per device, but it adds up across 30+ always-on items.

What to check:

• • Second fridge in the garage. Old beer fridges can cost $200+/year on their own.
• • Pool pumps running more than 6 hours/day. Most can be cut to 4 hours without issue.
• • Old plasma TVs, set-top boxes, gaming consoles in standby — switch to a smart power board.
• • Halogen downlights vs LED. Each LED swap saves ~$15/year.

Quick wins this weekend (under $300)

• Door seals and door snakes on every external door
• Self-adhesive foam strips around window sashes
• Exhaust fan dampers in bathrooms and laundry
• WELS 6L showerheads
• LED replacements for any halogen or CFL still installed
• Switch off the second fridge for a month and compare bills