London households pay some of the highest water bills in England, partly due to Thames Water metered tariffs and partly due to the sheer volume of water used in dense urban properties. This guide covers twelve practical measures that London homeowners and landlords can take to reduce water consumption and lower their bills without sacrificing comfort.
Why London Water Bills Are High and What You Can Do About It
Thames Water serves approximately 15 million customers across London and the Thames Valley, and the average London household on a water meter pays considerably more per year than the national average. The combination of high per-unit charges, surface water drainage levies, and the sheer water demand of London properties means that even a modest reduction in daily usage can translate into meaningful annual savings. For landlords with multiple properties, the cumulative saving across a portfolio can be substantial.
The twelve measures described in this guide range from zero-cost behavioural changes through to modest hardware upgrades costing between five and two hundred pounds. None of them require major building works or specialist contractors, although a plumber is recommended for some of the installation tasks.
1. Switch to a Water Meter if You Are Currently Unmetered
If your London property is still on an unmetered supply billed on rateable value, requesting a meter from Thames Water is free and can dramatically reduce your bill if your household is small relative to the property size. A two-person household in a three-bedroom property will almost certainly pay less on a meter than on the flat-rate unmetered tariff. Thames Water will install the meter free of charge and you have a 24-month trial period during which you can revert to unmetered billing if the meter turns out to be more expensive.
2. Fit Tap Aerators to Kitchen and Bathroom Taps
A tap aerator is a small screw-on device that mixes air into the water stream, maintaining the perceived flow rate while reducing the actual volume of water delivered by 30 to 50 percent. Aerators cost between two and ten pounds per tap and can be fitted in minutes without any plumbing knowledge. In a typical London household with four or five taps, fitting aerators across all outlets can save several thousand litres per year.
3. Replace a Single-Flush Toilet with a Dual-Flush Model
Older single-flush toilets in London homes typically use nine to thirteen litres per flush. A modern dual-flush toilet uses six litres for a full flush and three to four litres for a reduced flush. In a household where the toilet is flushed five to eight times per day, upgrading to a dual-flush model reduces toilet water use by 30 to 50 percent. Thames Water offers a rebate scheme for dual-flush toilet upgrades in some tariff periods, so it is worth checking the current offerings on their website before purchasing.
4. Install a Cistern Displacement Device in an Existing Toilet
If replacing the toilet is not practical, a cistern displacement bag such as the Save-a-Flush bag or the Hippo the Water Saver device can be placed inside the cistern to reduce the volume of water used per flush by approximately one litre. Thames Water provides these devices free to eligible customers. While the saving per flush is modest, over a full year the cumulative reduction is meaningful.
5. Fix Dripping Taps Promptly
A dripping tap that produces one drip per second wastes approximately 5,500 litres of water per year. In London, where water costs roughly 0.3 to 0.4 pence per litre on a metered supply, that amounts to between sixteen and twenty-two pounds per year per dripping tap. Replacing a worn tap washer or cartridge is a straightforward task for a plumber and typically costs between forty and eighty pounds including parts and labour. If you have multiple dripping taps, addressing them all in a single visit reduces the per-tap call-out cost.
6. Check and Repair a Running Toilet
A toilet that runs continuously due to a failed flap valve or siphon wastes far more water than a dripping tap, typically between 200 and 400 litres per day. The tell-tale sign is a continuous hissing sound from the cistern or water trickling into the bowl after the flush has completed. A plumber can diagnose and repair a running toilet in under an hour, and the repair typically costs between sixty and one hundred pounds. At London water meter rates, a running toilet costs between twenty and fifty pounds per month in wasted water, so prompt repair pays for itself quickly.
7. Fit a Low-Flow Showerhead
Standard shower heads in London properties deliver between nine and twelve litres of water per minute. A modern low-flow aerating showerhead delivers five to seven litres per minute while maintaining a comfortable shower experience through the same air-entrainment technology used in tap aerators. For a household where two people shower daily for an average of eight minutes each, switching to a low-flow showerhead saves between 7,000 and 12,000 litres per year. At Thames Water metered rates, this equates to an annual saving of between twenty and forty pounds.
8. Shorten Shower Times
Reducing average shower time by two minutes per person per day is one of the simplest and most impactful water saving measures. A four-minute shower uses approximately forty litres with a standard showerhead, while a six-minute shower uses sixty litres. In a household of four people, cutting two minutes from each daily shower saves approximately 29,000 litres per year. Shower timers, which cost between two and five pounds, are available from most DIY stores and can be adhered to the shower screen as a reminder.
9. Use a Dishwasher Rather Than Washing Up by Hand
A modern A-rated dishwasher uses between seven and twelve litres per cycle when run on its eco programme, whereas washing the equivalent load by hand under a running tap typically uses between 40 and 60 litres. Running a full dishwasher once per day rather than hand washing saves between 100 and 180 litres per day, or between 36,000 and 65,000 litres per year. This is one of the counterintuitive water efficiency measures that many London households have not yet adopted.
10. Install a Rainwater Harvesting Butt for Garden Irrigation
In London, garden watering accounts for a significant proportion of summer water consumption, particularly for properties with substantial gardens in the outer boroughs. A standard 200-litre water butt connected to a downpipe from the roof collects rainwater for free and can supply the majority of a garden's irrigation needs during dry spells. Thames Water offers subsidised water butts to customers in some promotional periods, and they are widely available from DIY stores at prices between twenty and fifty pounds.
11. Insulate Pipes to Reduce Water Wasted Waiting for Hot Water
In older London properties with long pipe runs between the boiler or hot water cylinder and the outlets, a significant volume of cold water must be run off before hot water arrives at the tap or shower. Insulating hot water pipes reduces heat loss and means that the water in the pipes stays warm for longer, reducing the wait time and the volume of cold water wasted. Pipe lagging is inexpensive and can be fitted by a homeowner or plumber as part of a broader plumbing maintenance visit.
12. Check for Hidden Leaks Using Your Water Meter
A simple check using your water meter can identify hidden leaks in the supply pipework that may be wasting hundreds of litres per day without being visible. Turn off all water outlets in the property, note the meter reading, wait thirty minutes without using any water, and then check the reading again. If the meter has advanced, there is a leak somewhere in the supply pipework between the meter and the outlets. Prestige Engineers carry out leak detection across all London areas and can identify the source of hidden leaks using acoustic detection equipment.