UK Toilet Water Usage Data: Litres per Flush by Age of Toilet
Flush volume in Britain has been set by regulation rather than by the market, so the age of a WC predicts its water use more reliably than anything else about it. Furniture in Fashion's 2026 report sets out the volumes by era: the 6 litre maximum imposed on WCs installed from 2001 by the Water Supply (Water Fittings) Regulations 1999, the 7.5 litres commonly permitted under the earlier water byelaws, and the 9 litre and larger cisterns found in properties fitted before them. We explain why actual use is often higher than the marked capacity, covering silent flush valve leakage, internal overflows that discharge into the pan and hide a failed float valve, and the double flushing that cancels out dual flush savings. Practical checks and the case against replacing a working older suite are included....
