Water efficiency is often overlooked in discussions about home energy. It shouldn't be - heating water is one of the largest energy uses in a typical home, and reducing hot water consumption has a direct impact on energy bills and carbon emissions.
Around 17% of a typical UK home's energy use goes on heating water for baths, showers, washing up and laundry. Reducing hot water use therefore reduces energy use, carbon emissions and bills simultaneously.
Shorter showers - a typical shower uses around 10 litres per minute. Reducing shower time by two minutes saves around 20 litres per shower - around 7,300 litres per year. The energy saving is around 0.1 tonnes of CO₂ and £30-40 per year.
Low-flow showerheads - replacing a standard showerhead with a low-flow version reduces water use by 30-50% with minimal impact on perceived pressure. Cost around £20-50, payback typically under a year.
Washing at 30°C - 90% of washing machine energy goes on heating water. Switching from 40°C to 30°C reduces energy use per cycle by around 40%. Modern detergents clean effectively at 30°C.
Full loads only - running a washing machine or dishwasher with a full load uses the same energy as a half load. Waiting for a full load effectively halves the energy and water cost per item.
Fixing dripping taps - a dripping tap wastes around 5,500 litres of water per year. Replacement washers cost under £2.
A five-minute shower uses around 50 litres of water. A standard bath uses around 80 litres. Showers are generally more water-efficient than baths, though a long shower can use more water than a bath.
If your home has a hot water cylinder, ensure it's well insulated. A British Standard jacket costs around £15 and can save around £40 per year. Set the cylinder thermostat to 60°C - hot enough to prevent legionella bacteria growth, but no hotter than necessary.
Low-flow showerheads and shorter showers are the highest-impact, lowest-cost changes available. Washing at 30°C and running full loads are zero-cost habit changes with meaningful impact. Together these save around 0.2-0.3 tonnes of CO₂ per year and typically £50-100 on energy bills.
