Energy efficiency is not the same as doing without
Energy efficiency means delivering the same service with less energy: a lamp that provides the same light with fewer watts, or a home that stays comfortable with less heating because its insulation is better. Energy conservation also includes avoiding unnecessary use. Neither requires living in darkness or at an unsafe indoor temperature.
The International Energy Agency's 2025 assessment estimates that buildings account for around 30% of global energy demand. Household habits matter, but building fabric and heating equipment matter too. Turning off unused chargers alone cannot solve the whole problem.
Start with your bill and kilowatt-hours
Record the kWh on your electricity bill, the number of days in the billing period and, where possible, the same month last year. For example, 210 kWh over 30 days equals 7 kWh per day. Your total bill can include taxes and fixed charges, so it is not a reliable stand-in for energy use.
Note unusual weather, household occupancy, travel and new appliances. Keep electricity and gas or district-heating data separate. An appropriately rated plug-in power meter can help measure some appliances safely; it is not suitable for every device or installation.
Heating, cooling and insulation: where to begin
Check draughts around doors and windows, shading and curtains, and whether heating or cooling equipment needs routine servicing. Use a thermostat setting that suits comfort and health; modest adjustments may help, but there is no universal saving percentage. Manage rooms that are rarely used without creating moisture, freezing or equipment risks.
In summer, shade sun-facing windows and ventilate when outside conditions are suitable and safe. In winter, durable improvements often involve insulation and well-designed systems. Never block combustion-air vents, flues or required ventilation openings. Fixed electrical and gas installations require qualified professionals.
LED lighting, appliances and standby use
Replacing incandescent or halogen lamps with correctly specified LEDs can reduce electricity demand for comparable light. When choosing appliances, compare annual kWh on the energy label, capacity, expected lifetime and repairability—not just the purchase price. Replacing a functioning appliance prematurely is not always environmentally preferable once manufacturing and electronic waste are considered.
Keep refrigerator ventilation clear and follow the manufacturer's instructions. Use suitable full loads and programmes for laundry and dishwashing, and avoid unnecessarily hot cycles. Check auto-off settings on televisions and game consoles. Do not unplug medical, security or network devices without understanding their function.
A transparent calculation, not a savings promise
Suppose a 60 W lamp is replaced by a 9 W LED providing suitable light and used for three hours each day. The illustrative saving is (60 − 9) W × 3 hours × 365 days ÷ 1000 = 55.8 kWh per year. Actual results depend on usage, lamp performance and the tariff. Apply your own relevant unit price to estimate money saved.
Be cautious about unmeasured promises such as 'halve your bills instantly'. Compare before and after data under similar conditions; a single mild winter month is not proof that one measure caused the difference.
A seven-day home energy audit
Day 1: Record kWh and billing days from three bills. Day 2: Identify lights and devices left on unnecessarily. Day 3: Review lamps and lighting needs. Day 4: Check visible draughts and safe shading options. Day 5: Read appliance energy labels and programme guides. Day 6: Discuss comfort, health and feasibility with the household. Day 7: Select three realistic actions and set a date to review the results.
For school activities, compare anonymised kWh-per-day figures rather than sharing identifiable household bills. Do not ask students to alter electrical installations.
Common questions and misleading claims
Do all plugged-in devices use the same standby power? No; it varies by model. Is the lowest thermostat setting always best? No; health, moisture, frost protection and household needs come first. Is a new appliance always the greener option? No; repair, measured use and product lifespan also matter.
If my electricity use falls, does my carbon footprint fall by the same percentage? Not necessarily. The generation mix and other energy uses change the result. See our carbon footprint guide for context.
Sources and scope
These sources support general energy-efficiency principles. Actual savings depend on the building, climate, tariff and use patterns.