Millions of London properties are still billed for water on an unmetered basis using the historic rateable value of the property rather than actual consumption. For many households, switching to a metered supply with Thames Water can produce significant annual savings. This guide explains how to determine whether a meter switch would benefit your household, how the switching process works, and what to expect from the changeover.
How Unmetered Water Billing Works in London
Properties in London that have not had a water meter installed are billed by Thames Water on the basis of the historic rateable value of the property. Rateable values were set in 1973 as a measure of the rental value of properties at that time, and they bear little relationship to the current size, value, or water consumption of a property. As a result, many London households on unmetered billing pay a flat annual charge that may be significantly higher or lower than their actual water use would cost if they were on a meter.
The unmetered billing system tends to disadvantage small households in relatively large or high-value properties, and to benefit large households in smaller or lower-value properties. A single person or couple living in a three or four-bedroom property in a desirable part of London will typically pay a high unmetered charge based on the property rateable value, while their actual water consumption might be a fraction of what the bill implies. Conversely, a large family in a modest flat with a low rateable value might pay less than their consumption would cost on a meter.
How to Estimate Whether a Meter Would Save You Money
The quickest way to estimate whether switching to a meter would reduce your water bill is to use the Thames Water meter calculator, available on their website. The calculator asks for the number of people in the household and the current annual unmetered charge, and provides an estimate of what the household would pay on a meter based on average consumption data for households of that size in the London supply area.
As a rule of thumb, a metered supply is likely to be cheaper if the number of bedrooms in the property equals or exceeds the number of people living in it. A two-person household in a three-bedroom property will almost certainly save money by switching. A four-person household in a two-bedroom flat may not save money, as their actual consumption is likely to be close to or above the average consumption that the unmetered charge is designed to cover. The crossover point varies depending on the specific rateable value of the property and the current Thames Water unmetered tariff.
The Thames Water Meter Installation Process
Thames Water installs meters free of charge for customers who request one. The application can be made online through the Thames Water website or by telephone. The installation is typically carried out within 20 working days of the application, and a Thames Water contractor will fit the meter at the boundary of the property, usually in the footpath just outside the property boundary, without any need to access the interior of the property.
In some London properties, particularly those in older mansion blocks or purpose-built flats, individual meters for each flat may not be technically feasible if the water supply enters the building through a single shared rising main. In these cases, Thames Water may install a meter on the building main but individual flat billing on a metered basis may not be possible until the building pipework is reconfigured. Prestige Engineers can advise on the feasibility of individual metering in shared buildings and can carry out the internal pipework modifications required to enable individual metering where this is technically possible.
The 24-Month Trial Period
Thames Water operates a 24-month trial period for customers who switch to a meter. During this trial period, if at any point it becomes clear that the metered charges are higher than the previous unmetered charges, the customer can request to revert to unmetered billing at no charge. This protection means that there is no financial risk in requesting a meter: the worst outcome is that you revert to unmetered billing if the meter turns out to be more expensive.
After the 24-month trial period, the switch to metered billing becomes permanent. However, for households that have already established water-saving habits or made efficiency improvements such as fitting aerators, upgrading to a dual-flush toilet, or fixing leaks, the metered bill will reflect these savings directly in a way that unmetered billing never can.
Water Meter Installation in London Rental Properties
For landlords with London rental properties, the situation with water meters is more complex. In some tenancy arrangements, the landlord pays the water bill and includes it within the rent; in others, the tenant pays Thames Water directly. Where the landlord pays the water bill, there is a direct financial benefit to installing meters and reducing consumption through water-saving measures. Where tenants pay directly, the landlord may still benefit indirectly by making the property more attractive to cost-conscious tenants who are aware of water efficiency.
Thames Water will install a meter on request from the bill payer, which in landlord-pays arrangements is the landlord. In tenant-pays arrangements, the tenant has the right to request a meter installation as the Thames Water account holder. Prestige Engineers can assist landlords in navigating the meter installation process and in identifying and implementing the water-saving measures that will have the greatest impact on metered water bills across a portfolio of London properties.