This week's heatwave, with a red extreme heat warning and temperatures near 38°C, is a sharp reminder of how quickly water demand spikes and how regularly parts of the UK now slide towards drought and hosepipe restrictions. Against that backdrop, the UK is introducing Mandatory Water Efficiency Labelling.
What the scheme does
The scheme introduces a national A to F label, much like the familiar energy rating, for water-using products. The labelling covers toilets, urinals, bathroom basin taps, shower outlets and assemblies, dishwashers, washing machines and washer-dryers. The regulations have been developed in line with the international standard ISO 31600 and place obligations on both suppliers and dealers.
Suppliers must test their products to determine the correct water-efficiency band, produce the corresponding label, and supply that label to dealers free of charge. The aim is simple: make the water use of a product visible at the point of sale so customers can choose, and specifiers can recommend, more efficient fittings.
The label rates the product. It does not change the Building Regulations Part G water-efficiency calculation directly, and it excludes things like second-hand products, outdoor taps, instant-hot-water taps and commercial machines. Always check the current scope before advising a customer.
Why plumbers should care
Plumbers sit at the exact point where these choices get made. When a customer is choosing a new shower, mixer tap, toilet or appliance, you are the trusted voice on what to fit. A clear label makes it easier to steer customers towards efficient fittings, and it dovetails with the water-efficiency expectations that already sit in Part G of the Building Regulations for new dwellings.
It also pairs naturally with the wider water-system work you certify. Where you install or modify hot water systems, the documentation still matters; our guide to unvented hot water systems and G3 covers the certification side, and water hygiene risks should be captured in a legionella risk assessment where relevant.
For the official scope and timing, see the government consultation on UK mandatory water efficiency labelling.
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Published 2026-06-24. This article is for general guidance only and does not constitute legal or professional advice. Always refer to the relevant standards and consult qualified professionals for definitive requirements.