Last updated: February 2024

Byelaws & Guidance

Water Supply (Water Fittings) (Scotland) Byelaws (2014)


B​yelaw 1

(1) These Byelaws may be cited as the Water Supply (Water Fittings) (Scotland) Byelaws 2014 and, if confirmed with or without modification by the Scottish Ministers, come into force—

(a) if the date of coming into operation is fixed by the Scottish Ministers under paragraph 29 of Schedule 1 to the Water (Scotland) Act 1980, on that date; or

(b) if no date is so fixed, at the expiration of one month from the date of their confirmation.

(2) In these Byelaws—

“approved contractor” means a person who is—

(a) approved by Scottish Water for the area where a water fitting is installed or used;

(b) approved for the purposes of paragraph (a) of the definition of “approved contractor” in regulation 1 (2) of—

(i) the Water Supply (Water Fittings) Regulations 1999(b); or

(ii) the Water Supply (Water Fittings) Regulations (Northern Ireland) 2009(c); or

(c) certified as an approved contractor by an organisation specified pursuant to paragraph (b) of the definition of “approved contractor” in regulation 1(2) of the Water Supply (Water Fittings) Regulations 1999(d);

“domestic purposes”, in relation to the supply of water, is to be construed in accordance with section 7(1) and (2) (supply for domestic purposes) of the Water (Scotland) Act 1980;

“food production purposes” is to be construed in accordance with section 76L(1A) (interpretation etc.) of the Water (Scotland) Act 1980(e);

“grey water” means waste water from baths, showers, wash basins and washing machines;

“private water supply” has the same meaning as in regulation 2(1) of the Private Water Supply (Scotland) Regulations 2006(f);

“reclaimed water” means grey water after treatment which can be used for non- wholesome applications;

“supply pipe” means so much of any service pipe as is not vested in Scottish Water; and

“WC” means water-closet.

 

B​yelaw 2

(1) Subject to paragraphs (2) to (4), these Byelaws apply to any water fitting installed or used, or to be installed or used, in premises to which water is, or is to be, supplied by Scottish Water.

(2) These Byelaws do not apply to a water fitting installed or used, or to be installed or used, in connection with water supplied for purposes other than domestic purposes or food production purposes, provided that—

(a) the water is metered;

(b) the supply of the water is for a period not exceeding—

(i) one month; or

(ii) with the written consent of Scottish Water, three months; and

(c) no water can return through the meter to any pipe vested in Scottish Water.

(3) Except for the purposes of—

(a) byelaw 5(1) in so far as it applies in relation to the installation (in premises to which water is supplied by Scottish Water) of a system incorporating a private water supply; and

(b) paragraph 14 (prevention of cross-connection to unwholesome water) of Schedule 2,

these Byelaws do not apply to water fittings which are not, and are not to be, installed or used in connection with water supplied by Scottish Water.

(4) Nothing in these Byelaws requires any person to remove, replace, alter, disconnect or cease to use any water fitting which was lawfully—

(a) installed before these Byelaws come into force, and is so installed;

(b) in use; or

(c) capable of being used (but has not been so used), immediately before these Byelaws come into force.

 

B​yelaw 3

(1) No person may—

(a) install a water fitting to convey or receive water supplied by Scottish Water, or alter, disconnect or use such a water fitting; or

(b) cause or permit such a water fitting to be installed, altered, disconnected or used, in contravention of these Byelaws.

(2) No water fitting may be installed, connected, arranged or used in such a manner that it causes or is likely to cause—

(a) waste, misuse, undue consumption or contamination of water supplied by Scottish Water; or

(b) the erroneous measurement of water supplied by Scottish Water.

(3) Nowaterfittingmaybeinstalled,connected,arrangedorusedwhichbyreason of being damaged, worn or otherwise faulty, causes or is likely to cause—

(a) waste, misuse, undue consumption or contamination of water supplied by Scottish Water; or

(b) the erroneous measurement of water supplied by Scottish Water.

 

B​yelaw 4

(1) Every water fitting must be—

(a) of an appropriate quality and standard; and

(b) suitable for the circumstances in which it is used.

(2) A water fitting is of an appropriate quality or standard only if it—

(a) bears an appropriate CE marking in accordance with Regulation (EU) No 305/2011 of the European Parliament and of the Council laying down harmonised conditions for the marketing of construction products and repealing Council Directive 89/106/EEC(g);

(b) 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

(c) conforms to an appropriate specification approved pursuant to regulation 4(2)(d) of the Water Supply (Water Fittings) Regulations 1999.

(3) Without prejudice to paragraph (2), every water fitting must comply with the requirements of Schedule 2 as it applies to that fitting.

(4) Where any requirement of Schedule 2 relates to a water system, every water fitting which forms part of that system must be fitted or, as the case may be, altered or replaced so as to comply with that requirement.

(5) Every water fitting must be installed, connected, altered, repaired or disconnected so as to conform to—

(a) an appropriate British Standard, European Technical Assessment within the meaning of Regulation (EU) No 305/2011 (or European technical approval used as such in accordance with article 66(4) of that Regulation) or some other national specification of an EEA State which provides an equivalent level of protection and performance;

(b) an appropriate specification approved pursuant to regulation 4(6)(b) of the Water Supply (Water Fittings) Regulations 1999; or

(c) an appropriate method of installation approved by Scottish Water.

(6) Where Scottish Water approves a method of installation under paragraph (5)(c), it must—

(a) give notice of the approval to the Scottish Ministers; and

(b) publish the approval in such manner as Scottish Water considers appropriate.

(7) Paragraph (6) applies to the revocation or modification of an approval as it applies to the giving of that approval.

(8) In this byelaw, “EEA State” means a member State, Norway, Iceland or Leichtenstein.

 

B​yelaw 5

(1) Subject to paragraph (2), any person who proposes to install a water fitting in connection with any of the operations listed in the following table must—

(a) give notice to Scottish Water that that person proposes to begin work;

(b) not begin that work without the consent of Scottish Water which must not be withheld unreasonably; and

(c) comply with any conditions to which Scottish Water’s consent is subject.

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

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

(c) a single shower unit (which may consist of one or more shower heads within the unit) of a type specified pursuant to paragraph 4(c) of the table in regulation 5(1) of the Water Supply (Water Fittings) Regulations 1999, 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 backflow prevention device with a reduced pressure zone (RPZ valve)or other mechanical device for protection against a fluid which falls within fluid category 4 or fluid category 5;

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

(i) any water system laid outside a building and either less than 750 mm or more than 1350 mm below ground level;

(j) grey water, recycled water, reclaimed water and rainwater harvesting systems;

(k) water systems for fire fighting, including domestic sprinklers;

(l) a flexible shower hose or other flexible outlet for use in conjunction with a WC pan for personal cleansing;

(m) a shower-toilet or bidet-toilet where, either as part of the WC itself or as an addition or adaptation of it, a stream of water is provided from below the spillover level of the WC pan for personal cleansing; or

(n) any system incorporating a private water supply.

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 Scottish Water.

(2) Paragraph (1) does not apply to the installation by an approved contractor of a water fitting falling within the operations numbered 2, 4(b), 4(l) or 4(m) in the table in paragraph (1).

(3) The notice required by paragraph (1) must include or be accompanied by—

(a) the name and address of the person giving the notice, and (if different) the name and address of the person on whom notice may be served under paragraph (4);

(b) a description of the proposed work or material change of use;

(c) particulars of the location of the premises to which the proposal relates, and the use or intended use of those premises;

(d) except in the case of a fitting falling within the operations numbered 4(a), 4(c), 4(h) or 5 in the table above—

(i) a plan of those parts of the premises to which the proposal relates; and

(ii) a diagram showing the pipework and fitting to be installed; and

(e) where the work is to be carried out by an approved contractor, the name of the contractor.

(4) Scottish Water may withhold consent required under paragraph (1), or grant it subject to conditions, by a notice given before the expiry of the period of 10 working days commencing with the day on which notice under that paragraph was given.

(5) If no notice is given by Scottish Water within the period mentioned in paragraph (4), the consent required under paragraph (1) is to be deemed to have been granted unconditionally.

(6) In this byelaw—

“fluid category 4” means the category of fluid in paragraph 4 of Schedule 1; “fluid category 5” means the category of fluid in paragraph 5 of Schedule 1; and “material change of use” means a change in the purpose for which, or the circumstances in which, premises are used, such that after that change the premises are used (where previously they were not so used)—

(a) as a dwelling;

(b) as an institution;

(c) as a public building; or

(d) for the purposes of the storage or use of substances which if mixed with water result in a fluid which falls within fluid category 4 or fluid category 5.

 

Guidance to Byelaw 5

Scottish Water has its own notification form and dedicated contact as well as other information which can be found here.

Any questions please contact Scottish Water for advice.

Please note except for the items highlighted below a plan of those parts of the premises which relate to the proposed work and a diagram showing the pipework and fittings to be installed will be required.

 

A material change of use is defined in the water fittings regulations in England, Wales and Northern Irelandbyelaws in Scotland.

It is a change in the purpose for which a premises is used or the circumstances in which water within that premises will be used, specifically the introduction of new systems or appliances which are categorised as posing a fluid category 4 or 5 risk.

For example:

  1. The conversation of a house into a business premises or private business to a public building.

  2. A change of business use

  3. The installation of a new rainwater harvesting system, new high risk catering equipment or any new installation in healthcare.

 

B​yelaw 6

(1) Where a water fitting is installed, altered, connected or disconnected by an approved contractor, the contractor must, on completion of the work, give to the person who commissioned that work a signed certificate stating whether the water fitting complies with the requirements of these Byelaws.

(2) In the case of a fitting for which notice is required under byelaw 5(1)(as read with byelaw 5(2)), the contractor must send a copy of the certificate to Scottish Water.

 

Guidance to Byelaw 6

For the purposes of the water fittings regulations/byelaws approved contractor schemes are voluntary organisations for plumbers and plumbing contractors set up in accordance with regulation 1(2) of the water fittings regulations/byelaws. Approved contractors are either approved by a water undertaker or an organisation appointed by a regulator.

 

B​yelaw 7

(1) Subject to paragraph (2), a person commits an offence if the person—

(a) contravenes byelaw 3(1), 3(2), 3(3), 6(1) or 6(2);

(b) commences an operation listed in the table in byelaw 5(1)—

(i) without giving notice as required by that byelaw; or

(ii) without the consent required by that byelaw; or

(c) carries out an operation listed in the table in byelaw 5(1) in breach of a condition imposed under byelaw 5(4).

(2) In any proceedings against an owner or occupier for an offence under paragraph (1) which is based on the installation, alteration, repair, connection or disconnection of a water fitting, it is a defence to prove—

(a) that the work in question was carried out by or under the direction of an approved contractor; and

(b) that the contractor certified to the person who commissioned that work that the water fitting complied with the requirements of these Byelaws.

(3) A person who commits an offence under paragraph (1) is liable on summary conviction to a fine not exceeding level 5 on the standard scale.

 

Byelaw 8

(1) Where—

(a) an offence under these Byelaws has been committed by a body corporate or a Scottish partnership or other unincorporated association; and

(b) it is proved that the offence was committed with the consent or connivance of, or was attributable to any neglect on the part of—

(i) a relevant individual; or

(ii) an individual purporting to act in the capacity of a relevant individual, the individual as well as the body corporate, Scottish partnership or unincorporated association commits an offence and is liable to be proceeded against and punished accordingly.

(2) In paragraph (1), “relevant individual” means—

(a) in relation to a body corporate—

(i) a director, manager, secretary or other similar officer of the body;

(ii) where the affairs of the body are managed by its members, a member;

(b) in relation to a Scottish partnership, a partner; and

(c) in relation to an unincorporated association other than a Scottish partnership, a person who is concerned in the management or control of the association.

 


S​chedule 1: Fluid Categories

 

Fluid Category 1

Wholesome water supplied by Scottish Water and complying with the requirements of the Water Supply (Water Quality) (Scotland) Regulations 2001(i).

 

Fluid category 2

Water in fluid category 1 whose aesthetic quality is impaired owing to–

(a) a change in its temperature, or

(b) the presence of substances or organisms causing a change in its taste, odour or appearance, including water in a hot water distribution system.

 

Fluid category 3

Fluid which represents a slight health hazard because of the concentration of substances of low toxicity, including any fluid which contains–

(a) ethylene glycol, copper sulphate solution or similar chemical additives, or

(b) sodium hypochlorite (chloros and common disinfectants).

 

Fluid category 4

Fluid which represents a significant health hazard because of the concentration of toxic substances, including any fluid which contains–

(a) chemical, carcinogenic substances or pesticides (including insecticides and herbicides), or

(b) environmental organisms of potential health significance.

 

Fluid category 5

Fluid representing a serious health hazard because of the concentration of pathogenic organisms, radioactive or very toxic substances, including any fluid which contains–

(a) faecal material or other human waste;

(b) butchery or other animal waste; or

(c) pathogens from any other source.

 


S​chedule 2 : Requirements for Water Fittings

 

P​aragraph 1

I​n this Schedule—

“backflow” means flow upstream, that is in a direction contrary to the intended normal direction of flow, within or from a water fitting;

“cistern” means a fixed container for holding water at atmospheric pressure;

“combined feed and expansion cistern” means a cistern for supplying cold water to a hot water system without a separate expansion cistern;

“combined temperature and pressure relief valve” means a valve capable of performing the function of both a temperature relief valve and a pressure relief valve;

“contamination” includes any reduction in chemical or biological quality of water due to a change in temperature or the introduction of polluting substances;

“distributing pipe” means any pipe (other than a warning, overflow or flushing pipe) conveying water from a storage cistern, or from hot water apparatus supplied from a cistern and under pressure from that cistern;

“expansion cistern” or “expansion vessel” means a cistern or vessel connected to a water heating system which accommodates the increase in volume of water in the system when the water is heated from cold;

“expansion valve” means a pressure-activated valve designed to release expansion water from an unvented water heating system;

“flushing cistern” means a cistern provided with valve or device for controlling the discharge of the stored water into a water closet pan or urinal;

“overflow pipe” means a pipe from a cistern in which water flows only when the water level in the cistern exceeds a predetermined level;

“pressure relief valve” means a pressure-activated valve which opens automatically at a specified pressure to discharge fluid;

“primary circuit” means an assembly of water fittings in which water circulates between a boiler or other source of heat and a primary heat exchange inside a hot water storage vessel, and includes any space heating system;

“secondary circuit” means an assembly of water fittings in which water circulates in supply pipes or distributing pipes of a hot water storage system;

“secondary system” means an assembly of water fittings comprising the cold feed pipe, any hot water storage vessel, water heater and pipework from which hot water is conveyed to all points of draw-off;

“servicing valve” means a valve for shutting off for the purpose of maintenance or service the flow of water in a pipe connected to a water fitting;

“stop valve” means a valve, other than a servicing valve, used for shutting off the flow of water in a pipe;

“storage cistern” means a cistern for storing water for subsequent use, not being a flushing cistern;

“temperature relief valve” means a valve which opens automatically at a specified temperature to discharge fluid;

“terminal fitting” means a water outlet device; and

“vent pipe” means a pipe open to the atmosphere which exposes the system to atmospheric pressure at its boundary.

 

P​aragraph 2

(1) No material or substance (either alone or in combination with any other material or substance or with the contents of any water fitting of which it forms a part) which causes or is likely to cause contamination of water is to be used in the construction, installation, renewal, repair or replacement of any water fitting which conveys or receives, or may convey or receive, water supplied for domestic purposes or food production purposes.

(2) Sub-paragraph (1) does not apply to a water fitting downstream of a terminal fitting supplying wholesome water where—

(a) the use to which the water downstream is put does not require wholesome water; and

(b) a suitable arrangement or device to prevent backflow is installed.

 

G​uidance to Paragraph 2

Providing appropriate and adequate backflow protection against the highest level of risk downstream is installed, an installation not used to supply water for drinking, bathing, food preparation or cooking purposes is exempt from complying with schedule 2 paragraph 2(1).

Please note the backflow protection required needs to be assessed by the local water undertaker and other requirements of the water fittings regulations/byelaws continue to apply.

 

P​aragraph 3

Every water fitting shall be -

(a) immune to or protected from corrosion by galvanic action or by any other process which is likely to result in contamination or waste of water; and

(b) constructed of materials of such strength and thickness as to resist damage from any external load, vibration, stress or settlement, pressure surges, or temperature fluctuation to which it is likely to be subjected.

 

Guidance to Paragraph 3

All water fittings should be resistant to corrosion.

In the case of backflow prevention devices and any water fittings which are not going to be readily accessible in addition to being corrosion resistant they should be manufactured from materials which are not susceptible to dezincification. For example, gunmetal or CR brass.


Establishing whether a water fitting is suitable for installation is dependent upon a number of factors including but not limited to:

  1. Water fittings must be of an appropriate quality and standard

  2. System design, things considered include but are not limited to compatibility

    • with other water fittings within a plumbing system (e.g the potential for galvanic action)

    • system operational parameters (e.g. the maximum* and minimum pressure, temperature and flow the systems will be operating at)

  3. Location specific factors, things considered include but are not limited to:

    • the environment (e.g. ground or airborne contamination, the risk of frost damage, corrosion or dezincification, external load and ground movement)

    • product installation requirements and/or constraints (e.g. installed where light is excluded or only above ground)

    • installation backflow risks (e.g. the need for backflow protection to be installed)

  4. Requirements of schedule 2 as applicable.

* Please note all water fittings must be capable of withstanding an internal water pressure of not less than 1½ times the maximum pressure it will be subject to in operation.

 

P​argraph 4

Every water fitting shall be –

(a) watertight;

(b) constructed and installed so as to–

(i) prevent ingress by contaminants, and

(ii) inhibit damage by freezing or any other cause;

(c) installed so as to minimise the risk of permeation by, or deterioration from contact with, any substance which may cause contamination; and

(d) adequately supported.

 

Guidance to Paragraph 4

To be accepted as being of an appropriate quality and standard a water fitting should:

  • comply with regulation 4(1)(a)

  • be designed, constructed and installed so that it does not leak

  • be suitable for the environment in which it is to be installed

  • be installed in a manner which protects it from ingress, permeation or damage

  • adequately supported.

Useful sources of information include BS EN 806, and BS 8558.

Potential contamination risks to plumbing systems include but are not limited to:

  • Environmental contaminants passing through the body of water fittings. For example, hydrocarbons in soil permeating through plastic pipework.

  • Ingress of fluids, insects or animals through worn, damaged or incorrectly installed plumbing fittings, warning pipes and overflows. For example, a drain tap installed where it could become submerged in fluids such as groundwater; warning pipes discharging directly into sewerage pipes; rainwater or insects accessing a storage cistern via an unshrouded or unscreened weir overflow.

  • Warming of water. For example, storage tanks or pipework installed without adequate insulation.

  • Stagnation. For example, due to oversizing of storage systems, inconsistent demand or redundant ‘deadlegs’ pipework.

  • Use of non-compliant water fittings and materials. For example, lead solder used on wholesome water systems.

  • Backflow. For example, where no or incorrect backflow protection is installed.

 Potential sources of damage to water systems include but are not limited to:

  • Pipework laid at too shallow a depth being damaged by vehicles driving over it or flexing in as a consequence of ground movement.

  • Freezing. For example, due to installation outside the thermal envelope or insufficient insulation.

  • Changes in the integrity of plumbing fittings due to exposure to high temperatures, excessive pressures, ground or airborne substances, sunlight and/or fittings or materials which are incompatible. For example, galvanic action.

  • Lack of inspection and/or maintenance

  • Vandalism

 

P​aragraph 5

Every water fitting must be capable of withstanding an internal water pressure not less than 1½ times the maximum pressure to which that fitting is designed to be subjected in operation.

 

P​aragraph 6

No water fitting is to be installed, connected or used which is likely to have a detrimental effect on the quality or pressure of water in a water main or other pipe of Scottish Water.

 

P​aragraph 7

(1) No water fitting is to be embedded in any wall or solid floor.

(2) No fitting which is designed to be operated or maintained, whether manually or electronically, or which consists of a joint, is to be a concealed water fitting.

(3) Any concealed water fitting or mechanical backflow prevention device, not being a terminal fitting, shall be made of gunmetal, or another material resistant to dezincification.

(4) Any water fitting laid below ground level shall have a depth of cover sufficient to prevent water freezing in the fitting.

(5) In sub-paragraphs (2) and (3) “concealed water fitting” means a water fitting which–

(a) is installed below ground;

(b) passes through or under any wall, footing or foundation;

(c) is enclosed in any chase or duct; or

(d) is in any other position which is inaccessible or renders access difficult.

 

Guidance to Paragraph 7

Joints on concealed pipework are likely to lose their integrity over time and therefore should only be considered where unavoidable.

All water fittings should be resistant to corrosion. In the case of backflow prevention devices and any water fittings which are not going to be readily accessible in addition to being corrosion resistant they should be manufactured from materials which are not susceptible to dezincification. For example, gunmetal or CR brass.

To prevent waste there needs to be provision to access any joints or water fittings which require maintenance, such as backflow prevention devices, valves which control the flow and any other operational fitting.

Water fittings considered to be concealed include those:

  • Buried in the ground

  • Installed below or embedded in floors

  • Installed in or behind wall finishes

Water fittings considered not to be concealed include those:

  • Installed below ground but not buried, such as in a chamber or basement room

  • Installed below floors or in walls which can be readily accessed

 

 

 

 

 

 

P​aragraph 8

No water fitting is to be installed in such a position, or pass through such surroundings, that it is likely to cause contamination or damage to the material of the fitting or the contamination of water supplied by Scottish Water.

 

Guidance to Paragraph 8

When designing a compliant plumbing system a number of factors need to be considered, including but not limited to:

  • Avoiding the risk of contamination or damage resulting from the environment in which the system is to be installed or due to the design itself.

  • The required and attainable supply pressure and other operational parameters

  • User expectations and whether these are achievable

  • Suitability of water fittings for use

  • Providing appropriate, adequate backflow protection.

  • Water efficiency

  • Limiting waste.

Useful sources of information include BS EN 806and BS 8558

 

Paragraph 9

Any pipe supplying cold water for domestic purposes to any tap shall be so installed that, so far as is reasonably practicable, the water is not warmed above 20°C.

 

G​uidance to Paragraph 9

To minimise the risk of contamination resulting from microbial growth and wastage due to taps left to run, cold water distribution systems should be designed and installed to maintain a temperature not exceeding 20oC.

 

P​aragraph 10

(1) Every supply pipe or distributing pipe providing water to separate premises must be fitted with a stop valve conveniently located to enable the supply to those premises to be shut off without shutting off the supply to any other premises.

(2) Where a supply pipe or distributing pipe provides water in common to two or more premises, it must be fitted with a stop valve to which each occupier of those premises has access.

 

P​aragraph 11

(1) Water supply systems must be capable of being drained down and be fitted with an adequate number of servicing valves and drain taps so as to minimize the discharge of water when water fittings are maintained or replaced.

(2) A sufficient number of stop valves must be installed for isolating parts of the pipework.

 

Guidance to Paragraph 11

Servicing valves are used to isolate individual water fittings. Their purpose is to minimise waste when individual water fittings are maintained or replaced.

Stop valves isolate an area or 'zone' within a premises.

 

P​aragraph 12

(1) The water system must be capable of withstanding an internal water pressure (“the test pressure”) not less than 1½ times the maximum pressure to which the installation or relevant part is designed to be subjected in operation.

(2) This requirement is to be deemed to be satisfied–

(a) in the case of a water system that does not include a pipe made of plastics, where–

(i) the whole system is subjected to the test pressure by pumping, after which the test continues for one hour without further pumping;

(ii) the pressure in the system is maintained for one hour; and

(iii) there is no visible leakage throughout the test;

(b) in any other case, where either Test A or Test B is satisfied–

(3) For the purposes of sub-paragraph (2)(b)—

(a)“Test A” is satisfied if—

(i) the whole system is subjected to the test pressure by pumping for 30 minutes, after which the test continues for 90 minutes without further pumping;

(ii) the pressure is reduced to one third of the test pressure after 30 minutes;

(iii) the pressure does not drop below one third of the test pressure over the following 90 minutes; and there is no visible leakage throughout the test; and

(b)“Test B” is satisfied if—

(i) the whole system is subjected to the test pressure by pumping for 30 minutes, after which the pressure is noted and the test continues for 150 minutes without further pumping;

(ii) the drop in pressure is less than 0.6 bar (60kPa) after the following 30 minutes, or 0.8 bar (80kPa) after the following 150 minutes; and

(iii) there is no visible leakage throughout the test.

 

Guidance to Paragraph 12

To prevent waste all plumbing fittings must be capable of withstanding 1½ times the maximum operational pressure it will be subjected to once installed.

The test methods detailed in Schedule 2 paragraph 12 and BS EN 806 -2, can both be used to demonstrate compliance with this requirement

 

P​aragraph 13

Every water system must be tested, flushed and where necessary disinfected before it is first used.

 

Guidance to Paragraph 13

BS EN 806 - 4 provides guidance on how to flush and disinfect plumbing systems.

Where there is any doubt or further information is required contact the local water undertaker.

 

P​aragraph 14

(1) Any water fitting conveying–

(a) rain water, grey water recycled water, reclaimed water or any fluid other than water supplied by Scottish Water; or

(b) water for the purpose of a private water supply; or

(c) any fluid that is not wholesome water;

must be clearly identified so as to be easily distinguished from any supply pipe or distributing pipe.

(2) No supply pipe, distributing pipe or pump delivery pipe drawing water from a supply pipe or distributing pipe shall convey, or be connected so that it can convey, any fluid falling within sub- paragraph (1), unless a device for preventing backflow is installed in accordance with paragraph 15.

 

Guidance to Paragraph 14

Irrespective of what type of water is being conveyed all pipework and fittings should be marked in accordance with BS 1710. Further information can be found here.

Any water fitting conveying any fluid other than mains supplied water should not be directly connected to a plumbing system supplying mains drinking water

With the agreement of the local water undertaker a mains water back-up to an alternative water source system may be permitted subject to the installation of appropriate backflow protection.

 

P​aragraph 15

(1) Subject to sub-paragraphs (2) to (5), every water system must contain an adequate device or devices for preventing backflow of fluid from any appliance, fitting or process from occurring.

(2) Sub-paragraph (1) does not apply to—

(a) a water heater where the expanded water is permitted to flow back into a supply pipe; or

(b) a vented water storage vessel supplied from a storage cistern, where the temperature of the water in the supply pipe or the cistern does not exceed 20°C.

(3) The device used to prevent backflow must be appropriate to the highest applicable category of fluid in Schedule 1 to which the fitting is subject downstream before the next such device.

(4) Backflow prevention shall be provided on any supply pipe or distributing pipe—

(a) where it is necessary to prevent backflow between separately occupied premises; or

(b) where Scottish Water has given notice for the purposes of this Schedule that such prevention is needed for the whole or part of any premises.

(5) A backflow prevention device is adequate for the purposes of sub-paragraph (1) if it conforms to a specification approved for the purposes of paragraph 15(1) of Schedule 2 to the Water Supply (Water Fittings) Regulations 1999 (pursuant to sub-paragraph (5) of that paragraph).

 

Guidance to Paragraph 15

Guidance to paragraph 15(1)

In this paragraph reference to devices includes backflow protection arrangements.

Guidance to paragraph 15(2)

Thermal expansion from unvented water heaters (with the exception of instantaneous water heaters with a capacity less than 15 litres) may be accommodated within the secondary hot water system. However this is only allowed if:

  • The expanded water does not increase the temperature of the water in the supply pipe to in excess of 25°C in England and Wales 20°C in Scotland and Northern Ireland. As this may result in waste or impact on wholesomeness.

  • Both the expanded water plus any displacement can be accommodated within the supply pipe. It is not permissible for water displaced as a result of accommodating expansion to backflow into the pipework owned by the local water undertaker.

Guidance to paragraph 15(3)

The lowest level of backflow protection required as point of use protection must have a backflow protection rating which is at least equivalent to the highest fluid category of any downstream fluids an installation will be subjected to.

Guidance to paragraph 15(4)

Where a water undertaker considers there to be a likelihood, which cannot be reasonably ignored, of contamination by backflow within a premises or the wider network they can require additional backflow protection. In some circumstances as an alternative to this a higher level of point of use backflow protection may be permitted.

 

P​aragraph 16

(1) Every pipe supplying water connected to a storage cistern must be fitted with an effective adjustable valve capable of shutting off the inflow of water at a suitable level below the overflowing level of the cistern.

(2) Every inlet to a storage cistern, combined feed and expansion cistern, WC flushing cistern or urinal flushing cistern must be fitted with a servicing value on the inlet pipe adjacent to the cistern.

(3) Every storage cistern, except one supplying water to the primary circuit of a heating system, must be fitted with a servicing valve on the outlet pipe.

(4) Every storage cistern must be fitted with–

(a) an overflow pipe, with a suitable means of warning of an impending overflow, which excludes insects;

(b) a cover positioned so as to exclude light and insects; and

(c) thermal insulation to minimize freezing or undue warming.

(5) Every storage cistern must be so installed as to minimize the risk of contamination of stored water. The cistern must be of an appropriate size, and the pipe connections to the cistern shall be so positioned, as to allow free circulation and to prevent areas of stagnant water from developing.

 

Guidance to Paragraph 16

For the water stored in the cistern to remain wholesome it is important to minimise the risk of contamination. Key to this is making sure the water is stored for as short a period as possible. This is achieved through a combination of design and maintenance features and correctly sizing the cistern to ensure the regular turnover of the stored water and avoid stagnation as well as any deterioration of water quality.

Factors which should be considered when sizing a cistern include occupancy (intended and actual) and usage. Suggestions for storage capacity are given in BS EN 806-2

 

P​aragraph 17

(1) Every unvented water heater, not being an instantaneous water heater with a capacity not greater than 15 litres, and every secondary coil contained in a primary system must–

(a) be fitted with a temperature control device, a temperature relief device and a combined temperature pressure and relief valve; or

(b) be capable of accommodating expansion within the secondary hot water system.

(2) An expansion valve shall be fitted with provision to ensure that water is discharged in a correct manner in the event of a malfunction of the expansion vessel or system.

(3) Without prejudice to the general application of the requirements sub- paragraphs (1) and (2), those requirements are to be deemed to have been met if alternative safety devices are fitted—

(a) with at least an equivalent degree of safety in preventing the temperature of stored water exceeding 100°C; and

(b) which comply with the Building (Scotland) Regulations 2004(j) (including, in particular, paragraph 4.9 of Schedule 5 to those Regulations) and the associated guidance having effect in accordance with section 4(1) and (2) of the Building (Scotland) Act 2003(k).

 

Guidance to Paragraph 17

All unvented hot water heaters must be capable of accommodating expansion or fitted with adequate safety arrangement to prevent systems overheating and over pressurising.

Accommodation of expansion

The water fittings regulations/byelaws permit accommodation within the secondary hot water system, of thermal expansion from unvented water heaters (with the exception of instantaneous water heaters with a capacity less than 15 litres).

This is however only allowed if:

  • The expanded water does not increase the temperature of the water in the supply pipe to in excess of 25°C in England and Wales 20°C in Scotland and Northern Ireland. As this may result in waste or impact on wholesomeness.

  • Both the expanded water plus any displacement can be accommodated within the supply pipe. It is not permissible for water displaced as a result of accommodating expansion to backflow into the pipework owned by the local water undertaker.

 Acceptable safety devices include:

  • Temperature relief valves

  • Temperature control arrangements such as non-self-resetting energy cut outs and cylinder thermostats (interlocked to prevent flow from the primary circuit).

  • Combined temperature and pressure relief valves

  • Pressure reducing valves

  • Expansion vessels installed in combination with expansion relief valves.

 For further information, including advice about safety device arrangements for different methods of heating, please refer to the relevant version of the Building Regulations.

The water fittings regulations/byelaws permit accommodation within the secondary hot water system, of thermal expansion from unvented water heaters (with the exception of instantaneous water heaters with a capacity less than 15 litres).

Please note: in England, Wales and Scotland this requirement is met by safety devices which satisfy the relevant Building Regulations.

 

P​aragraph 18

Appropriate vent pipes, temperature control devices and combined temperature pressure and relief valves must be provided to prevent the temperature of the water within a secondary hot water system from exceeding 100°C.

 

Guidance to Paragraph 18

The safety arrangements installed on a water heater used to heat water for domestic applications should prevent the temperature exceeding 100oC.

The suitability of safety arrangements for other applications, for example industrial processes will be assessed on a case by case basis.

Where the source of heat energy cannot be relied upon in all circumstances to achieve the required minimum temperature to address concerns about microbiological growth an additional heat source should be available.

Please note: in England, Wales and Scotland this requirement is met by safety devices which satisfy the relevant Building Regulations.

 

P​aragraph 19

Discharges from temperature relief valves, combined temperature and pressure and relief valves and expansion valves must be made in a safe and conspicuous manner.

 

P​aragraph 20

(1) No vent pipe from a primary circuit is to terminate over a storage cistern containing wholesome water for domestic supply or for supplying water to a secondary system.

(2) No vent pipe from a secondary circuit is to terminate over any combined feed and expansion cistern connection to a primary circuit.

(3) In sub-paragraph (1) “secondary system” means an assembly of water fittings comprising the cold feed pipe, any hot water storage vessel, water heater and pipework from which hot water is conveyed to all points of draw-off.

 

Guidance to Paragraph 20

In addition to the above requirements, where a cold water cistern supplying water for drinking, bathing, washing, cooking and other sanitary purposes, is used to accommodate the expansion of water within a secondary (hot water) system, the expanded water should not raise the temperature of the stored water to more than 25°C in England and Wales, 20°C in Scotland and Northern Ireland.

 

Paragraph 21

Every expansion cistern or expansion vessel, and every cold water combined feed and expansion cistern connected to a primary circuit, must be such as to accommodate any expansion water from that circuit during normal operation.

 

P​aragraph 22

(1) Every expansion valve, temperature relief valve or combined temperature and pressure relief valve connected to any fitting or appliance must close automatically after a discharge of water.

(2) Every expansion valve must–

(a) be fitted on the supply pipe close to the hot water vessel and without any intervening valves; and

(b) only discharge water when subjected to a water pressure of not less than 0.5 bar (50 kPa) above the pressure to which the hot water vessel is, or is likely to be, subjected in normal operation.

 

P​aragraph 23

(1) A temperature relief valve or combined temperature and pressure relief valve must be provided on every unvented hot water storage vessel with a capacity greater than 15 litres.

(2) The valve must–

(a) be located directly on the vessel in an appropriate location, and have a sufficient discharge capacity, to ensure that the temperature of the stored water does not exceed 100°C; and

(b) only discharge water at below its operating temperature when subjected to a pressure of not less than 0.5 bar (50 kPa) in excess of the greater of the following–

(i) the maximum working pressure in the vessel in which it is fitted, or

(ii) the operating pressure of the expansion valve.

(3) In this paragraph (1) “unvented hot water storage vessel” means a hot water storage vessel that does not have a vent pipe to the atmosphere.

(4) Without prejudice to the general application of the requirements of sub- paragraphs (1) and (2), those requirements are to be deemed to have been met if alternative safety devices are fitted—

(a) with at least an equivalent degree of safety in preventing the temperature of stored water exceeding 100°C; and

(b) which comply with the Building (Scotland) Regulations 2004 (including, in particular, paragraph 4.9 of Schedule 5 to those Regulations) and the associated guidance having effect in accordance with section 4(1) and (2) of the Building (Scotland) Act 2003.

 

Guidance to Paragraph 23

Please note: in England, Wales and Scotland this requirement is met by safety devices which satisfy the relevant Building Regulations.

 

P​aragraph 24

No supply pipe or secondary circuit is to be permanently connected to a closed circuit for filling a heating system unless it incorporates a backflow prevention device which conforms to a specification approved for the purposes of, and pursuant to, paragraph 24 of Schedule 2 to the Water Supply (Water Fittings) Regulations 1999.

 

P​aragraph 25

(1) Subject to sub-paragraphs (2) to (5)—

(a) every WC pan must be supplied with water from a flushing cistern, pressure flushing cistern or pressure flushing valve, and must be so made and installed that after normal use its contents can be cleared effectively by a single flush of water, or, where the installation is designed to receive flushes of different volumes, by the largest of those flushes;

(b) no pressure flushing valve is to be installed— (i) in a house; or (ii) in any building not being a house where a minimum flow rate of 1.2 litres per second cannot be achieved at the appliance;

(c) where a pressure flushing valve is connected to a supply pipe or distributing pipe, the flushing arrangement must incorporate a backflow prevention device consisting of a permanently vented pipe interrupter located not less than 150 mm above the spillover level of the WC pan or urinal;

(d) no flushing device installed for use with a WC pan is to give a single flush exceeding 6 litres;

(e) notwithstanding head (d), a flushing cistern installed before these Byelaws come into force may be replaced by a cistern which delivers a similar volume and which may be either single flush or dual flush, but a single flush cistern may not be so replaced by a dual flush cistern;

(f) no flushing device designed to give flushes of different volumes shall have a lesser flush exceeding two-thirds of the largest flush volume;

(g) every flushing cistern, other than a pressure flushing cistern, must be clearly marked internally with an indelible line to show the intended volume of flush, together with an indication of that volume;

(h) a flushing device designed to give flushes of different volumes must have—

(i) a readily discernible method of actuating the flush at different volumes; and

(ii) instructions, clearly and permanently marked on the cistern or displayed nearby, for operating it to obtain the different volumes of flush;

(i) every flushing cistern, not being a pressure flushing cistern or a urinal cistern, must be fitted with a warning pipe or with a no less effective device;

(j) every urinal that is cleared by water after use must be supplied with water from a flushing device which—

(i) in the case of a flushing cistern, is filled at a rate suitable for the installation;

(ii) in all cases, is designed or adapted to supply no more water than is necessary for effective flow over the internal surface of the urinal and for replacement of the fluid in the trap; and

(k) except in the case of a urinal which is flushed manually, or which is flushed automatically by electronic means after use, every pipe which supplies water to a flushing cistern or trough used for flushing a urinal must be fitted with an isolating valve controlled by a time switch and a lockable isolating valve, or with some other equally effective automatic device for regulating the periods during which the cistern may fill.

(2) Every WC, and every flushing device designed for use with a WC, must conform to a specification approved for the purposes of, and pursuant to, paragraph 25(2) of Schedule 2 to the Water Supply (Water Fittings) Regulations 1999.

(3) The requirements of sub-paragraphs (1) and (2) do not apply where faeces or urine are disposed of through an appliance that does not solely use fluid to remove the contents.

(4) The requirement in sub-paragraph (1)(j) is to be deemed to be satisfied—

(a) in the case of an automatically operated flushing cistern servicing urinals, where it is filled with water at a rate not exceeding—

(i) 10 litres per hour, for a cistern serving a single urinal; or

(ii) 7.5 litres per hour per urinal bowl or stall, or, as the case may be, for each 700 mm width of urinal slab, for a cistern serving two or more urinals; and

(b) in the case of a manually or automatically operated pressure flushing valve used for flushing urinals, where it delivers not more than 1.5 litres per bowl or position each time the device is operated.

(5) In this paragraph—

“ pressure flushing cistern” means a WC flushing device that utilises the pressure of water within the cistern supply pipe to compress air and increase the pressure of water available for flushing a WC pan;

“ pressure flushing valve” means a self-closing valve supplied with water directly from a supply pipe or a distributing pipe which when activated will discharge a pre-determined flush volume;

“ trap” means a pipe fitting, or part of a sanitary appliance, that retains liquid to prevent the passage of foul air; and “ warning pipe” means an overflow pipe whose outlet is located in a position where the discharge of water can readily be seen.

 

P​aragraph 26

All premises supplied with water for domestic purposes must have at least one tap conveniently situated for the drawing of drinking water.

 

Guidance to Paragraph 26

Where possible drinking water taps should be directly connected to the incoming mains water supply i.e. not via any water fitting which stores, treats or filters the water.

 

P​aragraph 27

A drinking water tap must be supplied with water from—

(a) a supply pipe;

(b) a pump delivery pipe drawing water from a supply pipe; or

(c) a distributing pipe drawing water exclusively from a storage cistern supplying wholesome water.

 

Guidance to Paragraph 27

Where it is not feasible for a drinking water tap to be directly connected to the incoming mains water supply (for example when fed from a storage cistern or via a water softener or conditioner) the wholesomeness of the water must be maintained to the intended drinking water tap(s), meaning the water fittings used must not adversely affect water quality.

 

P​aragraph 28

(1) Every bath, wash basin, sink or similar appliance must be provided with a watertight and readily accessible plug or other device capable of closing the waste outlet.

(2) Sub-paragraph (1) does not apply to—

(a) an appliance where the only taps provided are spray taps;

(b) a washing trough or wash basin whose waste outlet is incapable of accepting a plug and to which water is delivered at a rate not exceeding 0.06 litres per second exclusively from a fitting designed or adapted for that purpose;

(c) a wash basin or washing trough fitted with self-closing taps;

(d) a shower bath or shower tray;

(e) a drinking water fountain or similar facility; or

(f) an appliance which is used in medical, dental or veterinary premises and is designed or adapted for use with an unplugged outlet.

 

P​aragraph 29

(1) Clothes washing machines, clothes washer-driers and dishwashers must be economical in the use of water.

(2) Sub-paragraph (1) is to be deemed to be satisfied in the case of machines having a water consumption per cycle of not greater than—

(a) for horizontal axis washing machines supplied with water for domestic purposes, 27 litres per kilogram of washload for a standard 60°C cotton cycle;

(b) for washer-driers supplied with water for domestic purposes, 48 litres per kilogram of washload for a standard 60°C cotton cycle; and

(c) for dishwashers supplied with water for domestic purposes, 4.5 litres per place setting.

 

P​aragraph 30

Every pipe which conveys water to a drinking vessel for animals or poultry must be fitted with—

(a) a float-operated valve, or some other no less effective device to control the inflow of water, which is—

(i) protected from damage and contamination; and

(ii) prevents contamination of the water supply; and

(b) a stop valve or servicing valve as appropriate.

 

P​aragraph 31

Every pond, fountain or pool (which uses, or is to use, water supplied by Scottish Water) must have an impervious lining or membrane to prevent the leakage or seepage of water.

 

 

 

 

 



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