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Water regulations

Water regulations

The regulations set legal requirements for the design, installation, operation and maintenance of plumbing systems, water fittings and water-using appliances. They have a specific purpose to prevent misuse, waste, undue consumption or erroneous measurement of water and, most importantly, to prevent contamination of drinking water.

Water companies are legally responsible for enforcing the regulations by carrying out inspections of new and some existing installations. 

Find out more from Water Regs UK

Read our Fact sheet - laying a new supply pipe for information on getting connected.

Notification of proposed work to plumbing systems

Under the regulations, you must let us know before you begin working on the categories of work listed below.

We will advise you within ten working days whether we give consent, or if there are conditions on which consent is granted. In some cases, additional information may be needed. We will not withhold consent unreasonably.

Categories of work which require notification of proposed work 
 1. The erection of a building or other structure, not being a pond or swimming pool.
 2. The extension or alteration of a water system on any premises other than a house*.
 3. A material change of use of any premises.
 4. The installation of - 

(a) a bath having a capacity, as measured to the centre line of overflow, of more than 230 litres;

(b) bidet with an ascending spray or flexible hose*;

(c) a shower unit with more than one showerhead within a single unit, not being a drench shower installed for reasons of safety or health, connected directly or indirectly to a supply pipe;

(d) a pump or booster drawing more than 12 litres per minute, connected directly or indirectly to a supply pipe;

(e) a unit which incorporates reverse osmosis;

(f) a water treatment unit which produces a waste water discharge or which requires the use of water for regeneration or cleaning;

(g) a reduced pressure zone valve assembly or other mechanical device for protection against a fluid which is in fluid category 4 or 5*;

(h) a garden watering system unless designed to be operated by hand; or

(i) any water system laid outside a building and either less than 750mm or more than 1350mm below ground level.
 5. The construction of a pond or swimming pool with a capacity greater than 10,000 litres which is designed to be replenished by automatic means and is to be filled with water supplied by a water undertaker.

* This type of work does not require prior notification if you are using an approved contractor under the Water Industry Approved Plumbers Scheme.

Read our factsheet on Approved Contractors Schemes.

Notification of proposed work to plumbing


If you are looking for a plumbing business, we recommend you select one which is an eligible member of an Approved Contractors Scheme, such as WaterSafe.

Using an approved contractor will give you the following benefits:

  • They are fully qualified to carry out plumbing work in homes and businesses, with specific training in Water Fittings Regulations. If you use a plumber that isn't qualified you may find the work is poorly installed, or worse, you are left with a risk that your water supply could become contaminated
  • You will be issued with a 'Work Completed' certificate, which protects you (or the property owner) if challenged by the water supplier enforcing the Regulations. Approved Contractors are required to put right any work which is found not to meet the requirements of the Regulations
  • In many cases, plumbers have a legal duty to notify the water supplier before they start work and this can lead to delays. Approved contractors do not normally need to provide this notification
  • Approved businesses hold public and employers' liability insurance
  • If you have any concerns about the work, there is an independent complaints procedure
  • Approved businesses are audited to check they are complying with the rules of their Approved Contractors Scheme

Find out more about WaterSafe.

Lead pipes

It's worth considering a replacement supply connection, even if you are just renovating an old house. If you are replacing a lead supply pipe, we will usually replace the section from our mains to the property boundary free of charge. Please read our lead factsheet for more details.

Fire sprinklers

It is important that these systems are fitted correctly to ensure they will work as expected, whilst protecting the drinking water supply from contamination. Read our installation of fire sprinklers factsheet for more information.

Rainwater harvesting and grey water

Rainwater harvesting and water re-use systems need to be well-designed as well as being installed and maintained by those who are competent to do so.

Useful information

Our fact sheets give you key information about water regulations and the steps you need to take:

More information for developers