The Tap-Turning Test: Would a Water Meter Really Save Your Household Money?

Water bills have a funny status in UK households. We moan about energy and broadband, but the water bill lands once a year, gets glanced at, and gets paid. Which is a shame, because it's one of the only bills where you genuinely get a choice about how you're charged — and where that choice can be worth a couple of hundred quid either way.

In England and Wales, if your home isn't already metered, you can usually ask your water company to fit one for free. No fitting fee, no fuss. But "free" isn't the same as "better", and the difference comes down to how many people live in your house and how they use water.

The five-minute check: are you paying for rooms you don't use?

Unmetered water bills are based on the old rateable value of your property — a system that harks back to a time before dishwashers, power showers and households with four teenagers in them. The practical upshot is that your bill reflects the sort of house you live in, not the number of people in it.

So the fastest sanity check is simply: does the size of my home match the number of people in it?

• One person in a three-bed semi or a family-sized flat? You're almost certainly paying over the odds.
• Two adults in a big Victorian terrace with a garden they barely water? Same story.
• Five people in a two-up-two-down? You're probably quids in on the current arrangement — leave it alone.

If you want an actual number rather than a hunch, the Consumer Council for Water runs a free water meter calculator. You feed in your household size, whether you have a dishwasher, how often people shower, whether there's a garden, and it produces an estimated annual metered bill. Take that figure, hold it next to your last unmetered bill, and you've got your answer in less time than it takes to boil the kettle.

What's actually on a metered bill

Before you trust any calculator, it helps to know what you're comparing. A metered bill normally has two moving parts:

A standing charge. A fixed annual amount covering meter reading, billing and the pipework. This is often smaller than the fixed element of an unmetered bill — but it's never zero.

A volumetric charge per cubic metre. This is the bit that moves. And here's the detail that catches people out: you usually pay a sewerage charge per cubic metre as well, calculated on the same volume. So a cubic metre that goes down the drain costs you roughly twice — once to come in, once to go out. Combined water and sewerage rates commonly land somewhere in the region of £3 to £4 per cubic metre, depending on your region, so check your company's published tariff rather than guessing.

Surface water drainage. A separate charge for rainwater running into the sewers. If your rain soaks away into a garden or soakaway instead, you can often claim a rebate — and that applies whether or not you have a meter.

The break-even sum

This is the whole article in one line:

(Your annual unmetered bill − metered standing charges) ÷ combined rate per cubic metre = the number of cubic metres you can use before the meter costs you more.

A worked example, using round numbers: an unmetered bill of £640, metered standing charges of £70, and a combined rate of £3.60 per cubic metre. Take £70 off £640, divide by £3.60, and you get roughly 158 cubic metres.

Now the useful bit. A careful two-person household typically gets through somewhere around 90 to 110 cubic metres a year. Four people might use 160 to 200. So in that example, a couple would likely save money and a family of five would likely lose it.

A rough planning figure: allow 50 to 60 cubic metres per person per year if everyone showers rather than baths, and add more for hosepipes, paddling pools, long garden summers and anyone who considers a bath a personality trait.

Who tends to win

Singles and couples in homes bigger than they need. Flat-dwellers. People who shower, run the dishwasher only when it's full, and haven't watered a lawn since 2019. Anyone already careful with energy usually does well on a meter too, because the habits overlap.

Who should think twice

Big families, especially with teenagers. Anyone with a power shower habit measured in podcasts rather than minutes. Gardens, hot tubs, ponds, pressure washers, or a car washed at home every fortnight. If two or three of those apply, the unmetered bill is quietly protecting you, and switching is a gift to your water company.

If you rent, read this bit

The account is usually in your name, so you're the one who pays — but the meter stays with the property after you leave. You generally don't need a landlord's permission for the water company to fit one, though it's worth a quick look at your tenancy for anything about alterations, and a quick word with the letting agent so nobody is surprised.

Crucially: in England and Wales you can ask to go back to unmetered charges within 12 months of the meter going in, at no cost — provided you still live there. Use that. A full year takes in the summer, when hosepipes and extra washing push usage up. If the numbers still work after a hot July, they'll work in January.

Free things to do first

Don't order a meter until you've done these, because they change the maths:

1. Find a leak. Read the meter late at night with every tap off, then again first thing. If it's moved, you're paying to water your own foundations. A leaking loo cistern can waste a shocking amount.
2. Adjust the cistern. A displacement device or a tweak to the float valve costs nothing and cuts every flush.
3. Ask for the freebies. Most water companies post out shower timers, tap aerators and cistern savers on request.
4. Claim the drainage rebate if rainwater doesn't drain to the sewer.
5. Check WaterSure if you're on certain benefits and have a medical need for extra water — it caps metered bills.
6. Ask about an assessed charge if a meter genuinely can't be fitted to your supply.
7. Note the opening reading on the day it's installed, and check again a month later. Mistakes happen.

Scotland and Northern Ireland work differently — charges sit with council tax bands in Scotland, and domestic water in Northern Ireland is funded through rates — so the meter question doesn't apply in the same way. Wales follows the same 12-month rule as England.

The verdict

Five minutes with a calculator and last year's bill tells you which side of the line you're on. If it's close, take the meter and use the year-long escape hatch. If you're one person in a house built for four, requesting a meter is one of the few genuinely easy savings left on a household budget — the sort of boring, unglamorous money admin that GopherMoney exists for.

And if the sums say stay put? You've just saved yourself an afternoon of paperwork and gained a decent reason to stop feeling guilty about the bath.