Plastic Piping Systems and Water Fittings Regulations / Byelaws

Any water fitting installed or used, or to be installed or used, in premises to which water is or is to be supplied by a water undertaker is subject to the provisions of one of the following regulations:

  • The Water Supply (Water Fittings) Regulations 1999 – for England and Wales
  • Water Supply (Water Fittings) (Scotland) Byelaws 2014
  • Water Supply (Water Fittings) Regulations (Northern Ireland) 2009

All national legislation can be consulted at The Water Supply (Water Fittings) (Scotland) Byelaws 2014 can be found on the Scottish Water website.

Water fitting in this context includes pipes, fittings and appliances inside buildings.

The BPF Pipes Group cannot take responsibility for interpretation of Regulations and Byelaws, but provide information on the means by which the manufacturers of plastic piping systems can demonstrate compliance. Water Regs UK can provide more information on interpretation of the guidelines -

The purpose of these Regulations / Byelaws is to protect public health (the safety of water supplied to a building for drinking and washing and contamination of the public supply from a building) and to avoid waste and misuse of the public water supply. These all state that:

Every water fitting shall:

(a) be of an appropriate quality and standard;

The means by which compliance can be demonstrated is set out in the Regulations or Byelaws. In summary, these are:

For the purposes of this regulation, a water fitting is of an appropriate quality or standard only if:

(a) it bears an appropriate CE marking;

(b) it conforms to an appropriate harmonised standard or European technical approval; (Northern Ireland only).  

(c) it conforms to an appropriate British Standard or some other national specification of an EEA State which provides an  equivalent level of protection and performance; or

(d) it conforms to a specification approved by the regulator.

How can this be demonstrated for plastic piping systems?

a) CE Marking

It is currently not possible, and not legal, to apply CE marking. CE Marking is therefore not an option for demonstrating compliance. More information on CE marking and UK CA marking Construction Products Regulation in UK and the introduction of the UKCA mark (

b) British Standard or equivalent

The water undertaker will need to be satisfied that the British Standard is appropriate and that all testing has been undertaken.

It is possible for a manufacturer to make a self-declaration of compliance with a British Standard, but it is more usual to provide evidence of third-party verification of compliance.

In addition, compliance with any water quality requirements needs to be demonstrated for non-metallic materials.

Who offers a service to evaluate evidence and approve products?

KIWA UKKiwa UK Water Regulation 4 Testing and Certification (KUKreg4) | Kiwa

NSF WalesNSF REG4 Certification | NSF

c) Specification approved by the Regulator

The Regulators' Specification consists of a series of test code sheets, 230 in total. These have been the basis for demonstrating compliance to the Water Regulations / Water Byelaws through self-declaration or the Water Regulations Advisory Scheme. For an individual water fitting or assembly of fittings, a number of test code sheets may apply.

Who offers a service to evaluate evidence and approve products?

WRASWRAS Product Approvals

NSF Wales: Regulators' Specifications for REG4 Compliance | NSF

KIWA UK: Regulators' Specifications for REG4 Compliance | KIWA

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