Plumbing regulations

The Water Supply (Water Fittings) Regulations 1999 set out the legal requirements for all plumbing systems, water fittings and water-using appliances within your property.


These regulations also cover the design, installation, repair and maintenance of plumbing systems.

What are the regulations for?

The regulations are designed to prevent drinking water from:

  • contamination
  • waste
  • misuse
  • undue consumption
  • erroneous measurement.

They apply at the property boundary at all buildings connected to the public water supply including properties that have a private supply connection.

What products should you use?

To ensure you meet plumbing regulations, you should only use products that have been tested and confirmed as suitable to carry drinking water within your property. 

Water is a food-grade product and like food packaging, pipes and fittings cannot contain harmful materials that may contaminate the water.

It is not illegal to sell unapproved fittings, but it is against the law to install them into a plumbing system, so it’s best to check their suitability before buying.

Using unapproved fittings can also lead to the contamination of your drinking water. Some contamination can be harmful to health or result in unpleasant tastes and odours.

The following three approval bodies test and approve products and materials to ensure they are suitable for use with drinking water:

Search for the products and materials you need using their directories.

Notifying us about changes to your plumbing

If you plan on installing or altering your plumbing system, you may have to let us know before work begins.

Learn more about the types of work you need to let us know about and how to notify us about changes to your plumbing.