The Building Regulations 2010 - Sanitation, hot water safety and

The Building Regulations 2010

G1 Cold water supply

G2 Water efﬁciency

G3 Hot water supply and systems

G4 Sanitary conveniences and washing facilities

G5 Bathrooms

G6 Food preparation areas

Water efﬁciency calculator for new dwellings

APPROVED DOCUMENT

Sanitation, hot water safety

and water efﬁciency

2015 edition

with 2016 amendments

For use in England*

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MAIN CHANGES IN THE

2015 EDITION

This approved document supports Regulation

36 and Part G of Schedule 1 to the Building

Regulations 2010. It takes effect on 1 October

2015 for use in England*. The 2010 edition, as

amended, will continue to apply to work started

before 1 October 2015 or work subject to a

building notice, full plans application or initial

notice submitted before that date.

The main changes are:

• Introduction of an optional requirement for

tighter water efﬁciency in Regulation 36

(section G2).

• Introduction of a ﬁttings approach as an

alternative to using the water efﬁciency

calculator (section G2).

• Inclusion of the water efﬁciency calculator

methodology into this approved document,

with minor alterations resulting from European

efﬁciency labelling and consequential

amendments resulting from removal of

references to the Code for Sustainable Homes

(Appendix A).

• The annex listing the relevant competent

person self-certiﬁcation schemes has been

deleted.

CHANGE MADE BY THE

2016 AMENDMENTS

The change, made to section G2, requires the

water efﬁciency calculator to be completed for new

dwellings where a shower will not be provided.

* This approved document gives guidance for

compliance with the Building Regulations for

building work carried out in England. It also

applies to building work carried out on excepted

energy buildings in Wales as deﬁned in the Welsh

Ministers (Transfer of Functions) (No 2) Order 2009.

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Approved Document G

Sanitation, hot water safety and water efﬁciency

PAGE

Introduction 3

What is an Approved Document? 3

Consideration of technical risk 3

How to use this Approved Document 4

Where you can get further help 4

Responsibility for compliance 4

The requirements 5

Limitation on requirements 5

General guidance 6

Key terms 6

Types of work covered by this

Approved Document 7

Material change of use 8

Historic buildings 8

Notiﬁcation of work 8

Exemptions 9

Materials and workmanship 10

Supplementary guidance 10

Interaction with other legislation 10

G1: Cold water supply 12

The requirement 12

Guidance 13

Performance 13

Wholesome water 14

Softened wholesome water 14

Alternative sources of water 14

G2: Water efﬁciency 15

The requirement 15

Guidance 16

Performance 16

General 16

Fittings approach 16

Optional requirement 17

Notiﬁcation of water efﬁciency

calculation to the BCB 17

PAGE

G3: Hot water supply and systems 18

The requirement 18

Guidance 19

Performance 19

General 19

Provision of hot water supply 20

Design and installation of directly

or indirectly heated hot water

storage systems 20

Safety devices 22

Electric water heating 23

Solar water heating 23

Discharge pipe from safety devices 23

Prevention of excessive temperatures 26

Prevention of scalding 26

Installation 26

Commissioning of ﬁxed building

services 26

Notice of completion of commissioning 27

G4: Sanitary conveniences and

washing facilities 28

The requirement 28

Guidance 29

Performance 29

General 29

Scale of provision and layout

in dwellings 29

Scale of provision and layout in

buildings other than dwellings 30

Chemical and composting toilets 31

Discharges to drains 31

G5: Bathrooms 32

The requirement 32

Guidance 33

Performance 33

General 33

Scale of provision and layout

in dwellings 33

Scale of provision and layout in

buildings with rooms for residential

purposes 33

Discharges to drains 33

Contents

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Sanitation, hot water safety and water efﬁciency Approved Document G

G CONTENTS

PAGE

G6: Food preparation areas 34

The requirement 34

Guidance 35

Performance 35

Scale of provision in dwellings 35

Scale of provision in buildings other

than dwellings 35

Discharges to drains 35

Appendix A: Water efﬁciency calculator

for new dwellings 36

Appendix B: Wholesome water 45

Appendix C: References 47

Relevant legislation 47

Standards 47

Other documents 48

Index 49

DIAGRAMS

1. Typical discharge pipe arrangement 24

2. Separation between hand

washbasin/WC and food

preparation area – single room 30

3. Separation between hand

washbasin/WC and food

preparation area – two rooms 30

TABLES

2.1 Maximum ﬁttings consumption 16

2.2 Maximum ﬁttings consumption

optional requirement level 17

3.1 Sizing of copper discharge pipe

‘D2’ for common temperature

relief valve outlet sizes 25

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Approved Document G

Sanitation, hot water safety and water efﬁciency

What is an Approved Document?

This document has been approved and issued

by the Secretary of State to provide practical

guidance on ways of complying with Requirements

G1 to G6 and regulations 7 and 36 of the Building

Regulations 2010 (SI 2010/2214) for England and

Wales, as amended. The Building Regulations

2010 are referred to throughout the remainder

of this Document as ‘the Building Regulations’.

Where appropriate the Approved Document also

gives guidance on relevant requirements in the

Building (Approved Inspectors etc.) Regulations

2010 (SI 2010/2215).

The intention of issuing Approved Documents

is to provide guidance about compliance with

speciﬁc aspects of the Building Regulations in

some of the more common building situations.

They include examples of what, in ordinary

circumstances, may be reasonable provision for

compliance with the relevant requirement(s)

of the Building Regulations to which they refer.

If guidance in an Approved Document is followed

there will be a presumption of compliance with the

requirement(s) covered by the guidance. However,

this presumption is not conclusive, so simply

following guidance does not guarantee compliance

in an individual case. It is also important to note

that there may well be other ways of achieving

compliance with the requirements. There is

therefore no obligation to adopt any particular

solution contained in this Approved Document if

you would prefer to meet the relevant requirement

in some other way. However, persons intending

to carry out building work should always check

with their Building Control Body (BCB), either the

local authority or an Approved Inspector, that

their proposals comply with Building Regulations.

The guidance contained in this Approved Document

relates only to the particular requirements of the

Building Regulations that the document addresses

(see ‘Requirements’ below). However, building work

may be subject to more than one requirement of

the Building Regulations. In such cases the work

will also have to comply with any other applicable

requirements of the Building Regulations.

This document is one of a series that has been

approved and issued by the Secretary of State

for the purpose of providing practical guidance

with respect to the requirements of Schedule 1

and regulation 7 of the Building Regulations 2010

(SI 2010/2214) for England and Wales.

At the back of this document is a list of all the

documents that have been approved and issued

by the Secretary of State for this purpose.

Consideration of technical risk

In relation to the installation of new and

replacement sanitation and hot water services,

building work must satisfy all the technical

requirements set out in Schedule 1 to the

Building Regulations. Attention should be paid

in particular to the need to comply with Part

A (Structure), Part B (Fire safety), Part C (Site

preparation and resistance to contaminants and

moisture), Part J (Combustion appliances and

fuel storage systems), Part L (Conservation of

fuel and power) and Part P (Electrical safety),

as well as Part G.

Introduction

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Sanitation, hot water safety and water efﬁciency Approved Document G

G INTRODUCTION

How to use this Approved Document

In this document the following conventions

have been adopted to assist understanding and

interpretation:

a. Texts shown against

a green background

are extracts from the Building Regulations or

Building (Approved Inspectors etc.) Regulations,

and set out the legal requirements that relate

to compliance with the sanitation, hot water

safety and water efﬁciency requirements of

Building Regulations. It should be remembered

however that, as noted above, building works

must comply with all the other applicable

provisions of Building Regulations.

b. Key terms are deﬁned below and are printed

in bold italic text.

c. Details of technical publications referred to

in the text of this document are repeated

as references in Appendix C. A reference

to a publication is likely to be made for one

of two main reasons. The publication may

contain additional or more comprehensive

technical detail, which it would be impractical

to include in full in this Document but which

is needed to fully explain ways of meeting the

requirements; or it is a source of more general

information. The reason for the reference will

be indicated in each case. The reference will

be to a speciﬁed edition of the document.

The Approved Document may be amended

from time to time to include new references

or to refer to revised editions where this aids

compliance.

Where you can get further help

If you do not understand the technical guidance

or other information set out in this Approved

Document and the additional detailed technical

references to which it directs you, there are a

number of routes through which you can seek

further assistance:

– The Government website: www.gov.uk

– If you are the person undertaking the building

work you can seek assistance either from

your local authority building control service

or from your approved inspector (depending

on which building control service you are

using, or intend to use, to certify compliance

of your work with the requirements of the

Building Regulations).

– Businesses registered with a competent

person self-certiﬁcation scheme may be

able to get technical advice from their

scheme operator.

– If your query is of a highly technical nature

you may wish to seek the advice of a

specialist, or industry technical body, in

the area of concern.

Responsibility for compliance

It is important to remember that if you are the

person (e.g. designer, builder, installer) carrying

out building work to which any requirement

of Building Regulations applies you have a

responsibility to ensure that the work complies

with any such requirement. The building

owner may also have a responsibility for

ensuring compliance with Building Regulation

requirements and could be served with an

enforcement notice in cases of non-compliance.

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Approved Document G

Sanitation, hot water safety and water efﬁciency

This Approved Document deals with the

sanitation, hot water safety and water efﬁciency

requirements in the Building Regulations 2010.

Limitation on requirements

In accordance with regulation 8 of the Building

Regulations, the requirements in Parts A to D,

F to K and P (except for paragraphs G2, H2 and

J7) of Schedule 1 to the Building Regulations

do not require anything to be done except for

the purpose of securing reasonable standards

of health and safety for persons in or about

buildings (and any others who may be affected

by buildings or matters connected with buildings).

Paragraph G2 is excluded from regulation 8 as it

deals with the conservation of water. Paragraphs

H2 and J7 are excluded from regulation 8 because

they deal directly with prevention of the

contamination of water and of oil pollution. Parts

E and M (which deal, respectively, with resistance

to the passage of sound, and access to and use

of buildings) are excluded from regulation 8

because they address the welfare and convenience

of building users. Part L is excluded from regulation

8 because it addresses the conservation of fuel

and power. All these matters are amongst the

purposes, other than health and safety, that may

be addressed by Building Regulations.

The requirements

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Sanitation, hot water safety and water efﬁciency Approved Document G

Key terms

The following are key terms used in this document:

Note: Terms shown with * are deﬁned in

legislation, either in the Building Act 1984 or the

Building Regulations 2010, where the deﬁnition

may be fuller than the deﬁnition given here.

BCB means Building Control Body: a local

authority or an Approved Inspector.

*Building means any permanent or temporary

building, but not any other kind of structure or

erection, and a reference to a building includes

a reference to part of a building. This includes

dwellings (houses, ﬂats) and public buildings.

*Building work includes the erection or extension

of a building, the provision or extension of a

controlled service or ﬁtting in or in connection

with a building, and the material alteration of

a building, or a controlled service or ﬁtting.

Combined temperature and pressure relief

valve means a mechanically operated valve that

opens to discharge water when a ﬁxed (factory

set) temperature or ﬁxed (factory set) pressure

is exceeded.

Controlled service or ﬁtting includes a service

or ﬁtting subject to Schedule 1 requirements in

respect of sanitation, hot water safety, water

efﬁciency, drainage and waste disposal,

combustion appliances and fuel storage,

conservation of fuel or power, and electrical safety.

Direct heating means a method of heating in

which the heat source is integral with the hot water

vessel. Examples are an electrical immersion

heater, or a gas burner with a ﬂue arrangement

that passes through the vessel so that the

ﬂue transfers heat to the stored water, or the

circulation of water from a vessel situated near

a burner with a ﬂue arrangement so that the ﬂue

transfers heat to the circulating water.

Domestic hot water means water that has been

heated for cooking, food preparation, personal

washing or cleaning purposes. The term is used

irrespective of the type of building in which the

hot water system is installed.

*Earth-closet means a closet having a movable

receptacle for the reception of faecal matter and

its deodorisation by the use of earth, ashes or

chemicals, or by other methods. This will therefore

include chemical and composting toilets.

Exempt buildings and work means the erection

of any building or extension of a kind described

in regulation 9 of and Schedule 2 to the Building

Regulations 2010; or the carrying out of any

work to or in connection with such a building or

extension, if after the carrying out of that work it

is still a building or extension of a kind described

in that Schedule.

Expansion vessel means a vessel to temporarily

accommodate the expansion of water from the

unvented hot water storage vessel as it is heated.

Greywater is domestic wastewater excluding

faecal matter and urine. When appropriately treated

this may replace the use of wholesome water in

WCs, urinals, irrigation or washing machines.

Harvested rainwater means rainwater harvested

from roofs or other suitable surfaces and

collected and stored. When appropriately treated,

this may replace the use of wholesome water in

WCs, urinals, irrigation or washing machines.

Heated wholesome water means water that,

when cold, was wholesome in accordance with

the deﬁnition below and has been subjected to

a heat source to increase its temperature.

Hot water storage system means a vessel

for storing:

a. heated wholesome hot water or softened

wholesome hot water for subsequent use

b. water that is used to heat other water

together with any ancillary safety devices

described in paragraphs 3.10 and 3.11 of this

Approved Document and all other applicable

operating devices.

Hot water storage system package means

a hot water storage system having the

safety devices described in 3.10 and 3.17 of

this Approved Document factory-ﬁtted by the

manufacturer, together with a kit containing other

applicable devices supplied by the manufacturer

to be ﬁtted by the installer.

Hot water storage system unit means a hot

water storage system having the safety devices

described in 3.10 and 3.17 of this Approved

Document and all other applicable operating

devices factory-ﬁtted by the manufacturer.

Indirect heating means a method of heating

stored water through a heat exchanger.

Kitchen means a room or part of a room which

contains a sink and food preparation facilities

Material alteration means an alteration which

results in a building or a controlled service

or ﬁtting not complying with, or being more

unsatisfactory than it was before in relation to

Schedule 1 requirements in relation to structure,

means of warning and escape, internal and

external ﬁre spread, ﬁre service access and

facilities, and access and use.

Non-self-resetting energy cut-out means a

device that will interrupt the supply of heat to a

hot water storage vessel when a ﬁxed (factory

set) temperature is exceeded. If this protective

device is actuated it should only be possible to

reset it manually.

General guidance

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Approved Document G

Sanitation, hot water safety and water efﬁciency

GENERAL GUIDANCE G

Preparation of food means handling, making

and cooking of food.

Pressure relief valve means a mechanically

operated valve that opens to discharge water

when a ﬁxed (factory set) pressure is exceeded.

Primary thermal store means a store of heat

energy that can be used to heat domestic

hot water by means of a heat exchanger. The

thermal store can be heated by a variety of heat

sources. Primary hot water thermal stores can

be either vented or unvented.

Risk assessment for the purposes of this

document means the identiﬁcation of the hazards

associated with a process or activity combined

with an assessment of the probability and

consequences of each hazard.

*Room for residential purposes means a room,

or a suite of rooms, which is not a dwelling-

house or a ﬂat and which is used by one or

more persons to live and sleep in, and includes

a room in a hostel, a hotel, a boarding house, a

hall of residence or a residential home, but does

not include a room in a hospital, or other similar

establishment, used for patient accommodation.

Sanitary accommodation means a room

containing a WC or urinal, whether or not it also

contains other sanitary appliances. Sanitary

accommodation containing one or more

cubicles counts as a single space if there is

free circulation of air throughout the space.

Sanitary appliance means WC, urinal, bath,

shower, washbasin, sink, bidet and drinking

fountain. It also includes appliances that are not

connected to a water supply (e.g. composting

toilet) or drain (e.g. waterless urinal).

*Sanitary convenience means closets and urinals.

Sink means a receptacle used for holding water

(for preparation of food or washing up) supplied

through a tap and having a wastepipe.

*Softened wholesome water means water

which would be regarded as wholesome for the

purposes of regulations made under section

67 of the Water Industry Act 1991 (standards

of wholesomeness) as they apply for the

purposes of Part G of Schedule 1 in accordance

with paragraph (2c) but for the presence of

sodium in excess of the level speciﬁed in those

regulations if it is caused by a water softener

or water softening process which reduces the

concentrations of calcium and magnesium.

Tundish means a device, installed in the

discharge pipe from a valve, that provides an

air break allowing discharge to be conducted

safely to a place of termination. The tundish also

provides a visible indication of a discharge and

functions as backﬂow prevention device.

Temperature relief valve means a mechanically

operated valve that opens to discharge water

when a ﬁxed (factory set) temperature is

exceeded.

Unvented (closed) hot water storage system

means a vessel fed with cold water from a supply

pipe or dedicated storage cistern (without a

vent pipe) and in which water is heated directly

or indirectly. Expansion of the water when it is

heated is accommodated either internally or

externally and the system is ﬁtted with safety

devices to prevent water temperatures exceeding

100˚C, and other applicable operating devices to

control primary ﬂow, prevent backﬂow, control

working pressure and accommodate expansion.

Urinal means an appliance used for reception

and disposal of urine.

Vented (open) hot water storage system means

a vessel fed with cold water from a dedicated

storage cistern. Expansion of the water when

it is heated is accommodated through the cold

feed pipe. A vent pipe connecting the top of the

vessel to a point open to the atmosphere above

the cold water storage cistern is provided as a

safety device.

*Water-closet (WC) means a closet that has

a separate ﬁxed receptacle connected to a

drainage system and separate provision for

ﬂushing from a supply of clean water either by

the operation of a mechanism or by automatic

action. Water-closets are also referred to as WCs.

Wholesome water means water complying

with the requirements of regulations made under

Section 67 (Standards of wholesomeness) of the

Water Industry Act 1991. The regulations made

under this Section at the time of publication

of this Approved Document are for England

the Private Water Supplies Regulations 2009

(SI 2009/3101), for Wales the Private Water

Supplies (Wales) Regulations (SI 2010/66) and,

for England, the Water Supply (Water Quality)

Regulations 2000 (SI 2000/3184 as amended),

and, for Wales, the Water Supply (Water Quality)

Regulations 2001 (SI 2001/3911 as amended).

Types of work covered by this

Approved Document

Building work

Building work, as deﬁned in regulation 3 of the

Building Regulations 2010, includes the erection

and extension of a building, the provision or

extension of a controlled service or ﬁtting, and

the material alteration of a building or a controlled

service or ﬁtting. In addition, Building Regulations

may apply in cases where the purposes for

which or the manner or circumstances in which

a building or part of a building is used change in

a way that constitutes a material change of use.

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Sanitation, hot water safety and water efﬁciency Approved Document G

G GENERAL GUIDANCE

Under regulation 4 of the Building Regulations

2010, building work should be carried out in such

a way that, on completion of work,

i. the building complies with the applicable

Parts of Schedule 1 of the Building Regulations,

ii. in the case of an extension or material alteration

of a building, or the provision, extension or

material alteration of a controlled service or

ﬁtting, where it did not comply with any such

requirement, it is no more unsatisfactory in

relation to that requirement than before the

work was carried out.

Work described in Part G concerns the provision

or extension of controlled services or ﬁttings.

Work associated with installations covered in

these sections may be subject to other relevant

Parts of the Building Regulations.

Material change of use

A material change of use occurs in speciﬁed

circumstances in which a building or part of

a building that was previously used for one

purpose will be used in future for another. Where

there is a material change of use the Building

Regulations set requirements that must be met

before the building can be used for its new purpose.

Regulation 5 of the Building Regulations speciﬁes

the following circumstances as material changes

of use:

– a building is used as a dwelling where

previously it was not

– a building contains a ﬂat where previously

it did not

– a building is used as an hotel or boarding

house where previously it was not.

– a building is used as an institution where

previously it was not

– a building is used as a public building wher

previously it was not

– a building no longer comes within the

exemptions in Schedule 2 to the Building

Regulations where previously it did

– a building which contains at least one

dwelling contains a greater or lesser number

of dwellings than it did previously

– a building contains a room for residential

purposes where previously it did not

– a building which contains at least one room

for residential purposes contains a greater

or lesser number of such rooms than it did

previously

– a building is used as a shop where previously

it was not

Parts G1, G3(1) to (3) and G4 to G6 will apply to

all the material changes of use mentioned above.

This means that whenever such changes occur

the building must be brought up to the standards

required by Parts G1 and G3 to G6.

Parts G2, G3(4) and regulation 36 will apply

only to material changes of use where a building

is used as a dwelling where previously it was

not and where a building contains a ﬂat where

previously it did not.

Historic buildings

The types of building work covered by this

Approved Document may include work on

historic buildings. Historic buildings include:

a. listed buildings

b. buildings situated in designated conservation

areas

c. buildings which are of architectural or

historic interest and which are referred to as

a material consideration in a local authority’s

development plan

d. buildings of architectural and historical

interest within national parks, areas of

outstanding or natural beauty and world

heritage sites.

Special considerations may apply if the building

on which the work is to be carried out has special

historic or architectural value, and compliance with

the sanitation or hot water safety requirements

would unacceptably alter the character or

appearance of the building or parts of it.

When undertaking work on or in connection with

buildings with special historic or architectural

value, the aim should be to improve sanitation

and hot water safety where and to the extent

that it is possible provided that the work does

not prejudice the character of the host building

or increase the risk of long-term deterioration to

the building’s fabric or ﬁttings.

In arriving at a balance between historic building

conservation and sanitation or hot water safety

requirements, it would be appropriate to take

into account the advice of the local authority’s

conservation ofﬁcer before work begins.

Guidance is also available in the English Heritage

publication Building Regulations and Historic

Buildings, 2002 (revised 2004), which is available

at www.english-heritage.org.uk.

Note: Any building in the schedule of monuments

maintained under section 1 of the Ancient Monuments

and Archaeological Areas Act 1979 is exempt

from all Building Regulations requirements including

those in Part G.

Notiﬁcation of work

In almost all cases of new building work it will

be necessary to notify a BCB in advance of

any work starting. There are two exceptions

to this: where work is carried out under a self-

certiﬁcation scheme listed in Schedule 3, and

where work is listed in Schedule 4 to the Building

Regulations as being not notiﬁable.

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Approved Document G

Sanitation, hot water safety and water efﬁciency

GENERAL GUIDANCE G

Competent person self-certiﬁcation schemes

under Schedule 3

Under regulation 12(6) of the Building

Regulations it is not necessary to notify a BCB

in advance of work which is covered by this

Approved Document if that work is of a type set

out in column 1 of Schedule 3 to the Regulations

and is carried out by a person registered with a

relevant self-certiﬁcation (competent persons)

scheme as set out in column 2 of that Schedule.

In order to join such a scheme a person must

demonstrate competence to carry out the type

of work the scheme covers, and also the ability

to comply with all relevant requirements in the

Building Regulations. Details of current schemes

including those relating to sanitation, hot water

safety and water efﬁciency can be found at

www.gov.uk. These schemes may change from

time to time, or schemes may change name, or

new schemes may be authorised; so the current

list on the website should always be consulted.

Full details of the schemes can be found on the

individual scheme websites.

Where work is carried out by a person registered

with a competent person scheme, regulation

20 of the Building Regulations and regulation

20(1) of the Building (Approved Inspectors etc.)

Regulations 2010 require that the occupier of

the building be given, within 30 days of the

completion of the work, a certiﬁcate conﬁrming

that the work complies with all applicable

Building Regulation requirements. There is also a

requirement that the BCB be given a notice that

this has been done, or a copy of the certiﬁcate,

again within 30 days of the completion of the

work. These certiﬁcates and notices are usually

made available through the scheme operator.

BCBs are authorised to accept these certiﬁcates

as evidence of compliance with the requirements

of the Building Regulations. However, local

authority inspection and enforcement powers

remain unaffected, although they are normally

used only in response to a complaint that work

does not comply.

Work which is not notiﬁable under

Schedule 4

Schedule 4 to the Building Regulations sets out

types of work where there is no requirement

to notify a BCB that work is to be carried out.

These types of work are mainly of a minor nature

where there is no signiﬁcant risk to health, safety,

water efﬁciency or energy efﬁciency. Health,

safety, water efﬁciency and energy efﬁciency

requirements continue to apply to these types

of work; only the need to notify a BCB has

been removed.

Where only non-notiﬁable work as set out in

Schedule 4 is carried out, there is no requirement

for a certiﬁcate conﬁrming that the work complies

with Building Regulation requirements to be given

to the occupier or the BCB.

The types of non-notiﬁable work in Schedule 4

relevant to the sanitation, hot water safety and

water efﬁciency provisions of the Regulations are:

i. in an existing hot water system, the

replacement of any part which is not a

combustion appliance, or the addition of

an output device or control device. The

work will however remain notiﬁable where

commissioning is possible, and will affect

the reasonable use of fuel and power. This

is most likely to be where water heaters are

being provided

ii. the installation of a stand-alone, self-contained

ﬁxed hot water appliance. This is restricted

to a single appliance and any associated

controls and must not be connected to, or

form part of, any other ﬁxed building service.

However, if any of the following apply, the

work will remain notiﬁable building work:

– the service is a combustion appliance

– any electrical work associated with the

installation is notiﬁable

– commissioning is possible and would

affect the service’s energy efﬁciency,

such as that of water heaters

iii. the replacement of a sanitary convenience

with one that uses no more water than the

one it replaces, a washbasin, sink, bidet,

ﬁxed bath, or a shower but only where the

work does not include any work to:

– underground drainage

– the hot or cold water system or above-

ground drainage which could prejudice

the health and safety of any person on

completion of work

iv. replacing any part or adding an output or control

device to an existing cold water supply

v. providing a hot water storage system that

has a storage vessel with a capacity not

exceeding 15 litres provided that any electrical

work associated with the installation is also

not notiﬁable.

Schedule 4 also sets out what types of electrical

installation work in dwellings is non-notiﬁable.

Full information on this is given in Approved

Document P.

Exemptions

Schedule 2 to the Building Regulations sets out a

number of classes of buildings which are exempt

from all Building Regulations requirements.

However, the exemption has been removed in

respect of some requirements of Part G where

hot or cold water supply systems are shared

with other buildings. This is to help ensure that

the whole hot or cold water system is safe.

In particular:

i. the requirements of Parts G 1, G3(2) and G3(3)

will apply to any greenhouse which receives a

hot or cold water supply from a source shared

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G GENERAL GUIDANCE

with or located inside a dwelling

ii. the requirements of Parts G1, G3(2) and G3(3)

will apply to any small detached building

falling within Class 6 of Schedule 2 and any

extension falling within Class 7 of Schedule

2 (which includes conservatories under 30m

in area) which receives a hot or cold water

supply shared with or located inside any

building that is subject to the Regulations.

Please note that the Regulations do not require

the provision of hot or cold water systems to

such exempt buildings, but if such systems are

provided they must meet the minimum hygiene

and safety requirements in those Parts.

All other Classes of buildings within Schedule 2

retain their exemption from compliance with

Part G.

Materials and workmanship

Any building work which is subject to the

requirements imposed by Schedule 1 to the

Building Regulations shall be carried out in

accordance with regulation 7. Guidance on

meeting these requirements on materials and

workmanship is contained in Approved

Document 7.

Building Regulations are made for specific

purposes, primarily the health and safety, welfare

and convenience of people and for energy

conservation. Standards and other technical

specifications may provide relevant guidance to

the extent that they relate to these considerations.

However, they may also address other aspects of

performance or matters which, although they

relate to health and safety etc., are not covered by

the Building Regulations.

When an Approved Document makes reference

to a named standard, the relevant version of the

standard to which it refers is the one listed at the

end of the publication. However, if this version

has been revised or updated by the issuing

standards body, the new version may be used as

a source of guidance provided it continues to

address the relevant requirements of the

Regulations.

Supplementary guidance

The Department for Communities and Local

Government occasionally issues additional

material to aid interpretation of the guidance

in Approved Documents. This material may be

conveyed in ofﬁcial letters to chief executives of

local authorities and Approved Inspectors and/or

posted on the websites accessed through:

www.gov.uk.

Interaction with other legislation

This Approved Document makes reference to

other legislation, including those listed below,

that may also need to be considered.

Note: All statutory instruments can be accessed

at www.legislation.gov.uk.

The Water Supply (Water Quality) Regulations

2000 (SI 2000/3184 as amended), and in Wales

the Water Supply (Water Quality) Regulations

2001 (SI 2001/3911 as amended) are made under

the Water Industry Act 1991 and apply to the

supply of water by a statutory water undertaker

or a licensed water supplier. They make provision

for the wholesomeness of water supplied for

such domestic purposes as consist in or include

cooking, drinking, food preparation or washing;

or to premises in which food is produced.

The Water Supply (Water Fittings) Regulations

1999 (SI 1999/1148 as amended) are made under

the Water Industry Act 1991 and 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 a water undertaker. They make

provision for preventing contamination, waste,

misuse, undue consumption and erroneous

measurement of water supplied by a statutory

water undertaker or licensed water supplier.

The Private Water Supplies Regulations 2009

(SI 2009/3101) in England and The Private Water

Supplies (Wales) Regulations 2010 (SI 2010/66)

in Wales are made under the Water Industry

Act 1991 and section 2(2) of the European

Communications Act 1972 and are concerned

with the quality of water supplied from private

supplies for drinking, washing or cooking or for

food preparation purposes.

The Workplace (Health, Safety and Welfare)

Regulations 1992 (SI 1992/3004 as amended)

are made under the Health and Safety at Work

etc. Act 1974 and apply to any workplace or

part of a workplace. They apply to the common

parts of ﬂats and similar buildings if people

such as cleaners, wardens and caretakers are

employed to work in these common parts.

They make provision for, amongst other matters,

space requirements, cleaning and provision of

sanitary conveniences.

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Sanitation, hot water safety and water efﬁciency

GENERAL GUIDANCE G

Food Hygiene (England) Regulations 2006

(SI 2006/14 as amended) and the Food

Hygiene (Wales) Regulations 2006 (SI 2006/31

W5 as amended) are made under European

Communities Act 1972 and apply to measures

relating to food (including drink) including the

primary production of food. The provision of

washbasins and sinks is relevant to Approved

Document G.

Gas Safety (Installation and Use) Regulations

(SI 1998/2451) extend to all dangers arising

from the transmission, distribution, supply or

use of gas conveyed from a gas storage vessel.

The installation of gas heated water systems is

relevant to Approved Document G.

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G1 COLD WATER SUPPLY

This Approved Document deals with the following

Requirement from Part G of Schedule 1 to the

Building Regulations 2010.

Requirement Limits on application

Cold water supply

G1. (1) There must be a suitable installation for the provision of:

(a) wholesome water to any place where drinking water is

drawn off;

(b) wholesome water or softened wholesome water to any

washbasin or bidet provided in or adjacent to a room containing

a sanitary convenience;

washbasin, bidet, fixed bath or shower in a bathroom; and

(d) wholesome water to any sink provided in any area

where food is prepared.

(2) There must be a suitable installation for the provision of

water of suitable quality to any sanitary convenience fitted with

a flushing device.

The Requirement G1

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Sanitation, hot water safety and water efﬁciency

COLD WATER SUPPLY G1

Performance

In the Secretary of State’s view Requirement

G1(1) will be met if:

a. the water supplied is wholesome;

b. the pressure and ﬂow rate is sufﬁcient for the

operation of sanitary appliances planned in

the building;

c. the supply is reliable; and

d. the installation conveys wholesome water or

softened wholesome water to the sanitary

appliances and locations speciﬁed in the

Requirement without waste, misuse, undue

consumption or contamination of water.

The water will be wholesome if it is provided:

a. by a statutory water undertaker or a licensed

water supplier; or

b. by a source complying with the Private Water

Supplies Regulations 2009 (SI 2009/3101) in

England or the Private Water Supplies (Wales)

Regulations (SI 2010/66) in Wales.

In the Secretary of State’s view Requirement

G1(2) will be met if:

a. the water supplied is either wholesome,

softened wholesome or of suitable quality

having regard to the risks to health;

b. the pressure and ﬂow rate is sufﬁcient for the

operation of the sanitary appliances;

c. the supply is reliable; and

d. the installation conveys water to sanitary

appliances and locations speciﬁed in

the Requirement without waste, misuse,

undue consumption or contamination of

wholesome water.

Guidance

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G1 COLD WATER SUPPLY

Wholesome water

1.1 Water supplied to the building by a

statutory water undertaker or a licensed water

supplier through an installation complying with

the requirements of the Water Supply (Water

Fittings) Regulations 1999 (SI 1999/1148 as

amended) may be assumed to be wholesome

water. The requirements in the appropriate

water quality regulations are set out for ease

of reference in Appendix B to this Approved

Document.

1.2 Attention is drawn to the requirements

of the Water Supply (Water Fittings) Regulations

1999 (SI 1999/1148 as amended) which make

provision for preventing contamination, waste,

misuse, undue consumption and erroneous

measurement of water supplied by a water

undertaker or licensed water supplier.

1.3 Where a building is supplied with water

from a source other than a water undertaker

or licensed water supplier, the water shall be

considered to be wholesome if it meets the criteria

set out in the Private Water Supplies Regulations

2009 (SI 2009/3101) in England or the Private

Water Supplies (Wales) Regulations (SI 2010/66)

in Wales. The requirements in those regulations

are set out for ease of reference in Appendix B to

this Approved Document.

Softened wholesome water

1.4 Wholesome water which has been

treated by a water softener or a water softening

processes to adjust the content of hardness

minerals may have raised levels of sodium. Where

the water, after this treatment, still complies with

the requirements for wholesome water it is still

considered to be wholesome water.

1.5 However, where it complies with all

requirements for wholesome water other than

its sodium content, it will be considered to be

wholesome softened water. Whilst wholesome

softened water may be considered suitable for

most purposes it should not be provided in place

of wholesome water to any place where drinking

water is drawn off or to any sink provided in an

area where food is prepared.

Alternative sources of water

1.6 Water treated to the high standards of

wholesome water is not essential for all of the

uses that water is put to in and about buildings,

e.g. toilet ﬂushing, irrigation. A variety of alternative

sources are available for water. These include:

a. water abstracted from wells, springs, bore-

holes or water courses;

b. harvested rainwater;

c. reclaimed greywater; and

d. reclaimed industrial process water.

1.7 The design of treatment systems for

water from alternative sources should incorporate

measures to minimise the impact on water

quality of:

a. failure of any components;

b. failure to undertake any necessary

maintenance;

c. power failure where appropriate; and

d. any other measures identiﬁed in a risk

assessment.

1.8 Guidance on the marking of pipework

conveying water from alternative sources can

be found in the WRAS Information & Guidance

Note No. 9-02-05 Marking and identiﬁcation of

pipework for reclaimed (greywater) systems and

in BS 8515:2009 Rainwater harvesting systems –

Code of Practice.

1.9 Guidance on installing, modifying and

maintaining reclaimed water systems can be

found in the WRAS Information and Guidance

Note No. 9-02-04 Reclaimed water systems and

in BS 8515:2009 Rainwater harvesting systems.

Code of practice.

1.10 Information on the technical and economic

feasibility of rainwater and greywater can found

in MTP (2007) Rainwater and greywater: technical

and economic feasibility.

1.11 Information on the speciﬁcation of

rainwater and greywater systems can be found

in MTP (2007) Rainwater and greywater: a guide

for speciﬁers.

1.12 Guidelines for rainwater and greywater

systems, in relation to water quality standards,

can be found in MTP (2007) Rainwater and

greywater: review of water quality standards

alternative and recommendations for the UK.

1.13 Water from alternative sources may be

used in dwellings for sanitary conveniences,

washing machines and irrigation, provided the

appropriate risk assessment has been carried

out. A risk assessment should ensure that the

supply is appropriate to the situation in respect

of the source of the water and the treatment

of it, and not likely to cause waste, misuse,

undue consumption or contamination of

wholesome water.

1.14 Any system/unit used to supply dwellings

with water from alternative sources should be

subject to a risk assessment by the system

designer and manufacturer, and appropriate

testing carried out to demonstrate that any risks

have been suitably addressed. A risk assessment

should include consideration of the effect on

water quality of system failure and failure to carry

out necessary maintenance.

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Sanitation, hot water safety and water efﬁciency

WATER EFFICIENCY G2

This Approved Document deals with the following

Requirement from Part G of Schedule 1 and

regulation 36 to the Building Regulations 2010,

as amended.

Requirement Limits on application

Water efficiency

G2. Reasonable provision must be made by the installation of

fittings and fixed appliances that use water efficiently for the

prevention of undue consumption of water.

Water efficiency of new dwellings

36.—(1) The potential consumption of wholesome water by

persons occupying a new dwelling must not exceed

the requirement in paragraph (2).

(2)

The requirement refer

red to in paragraph (1) is either—

(a) 125 litres per person per day; or

(b)

in a case to w

hich paragraph (3) applies, the optional

requirement of 110 litres per person per day,

as measured in either case in accordance with a methodology

approved by the Secretary of State.

(3) This paragraph applies where the planning permission

under which the building work is carried out—

(a) speciﬁes the optional requirement in paragraph (2)(b); and

(b) makes it a condition that that requirement must be

complied with.

(4) In this Part, “new dwelling” does not include a dwelling

that is formed by a material change of use of a building

within the meaning of regulation 5(g).

Wholesome water consumption calculation

37.—(1) Where regulation 36 applies, the person carrying out

the work must give the local authority a notice which

speciﬁes—

(a) which of the requirements in regulation 36(2)(a) or (b)

applies to the dwelling; and

(b) the potential consumption of wholesome water per

person per day in relation to the completed dwelling.

Building (Approved Inspectors) Regulations 2010

Application of Provisions of the Principal Regulations

20.—(1) Regulation 20 (provisions applicable to self-

certiﬁcation schemes), 27 (CO

emission rate calculations),

29 (energy performance certiﬁcates), 37 (wholesome water

consumption calculation), 41 (sound insulation testing), 42

(mechanical ventilation air ﬂow rate testing), 43 (pressure

testing) and 44 (commissioning) of the Principal Regulations

apply in relation to building work which is the subject of

an initial notice as if references to the local authority were

references to the approved inspector.

(4) Regulation 37(2) of the Principal Regulations applies in

relation to building work which is the subject of an initial

notice as if after “work has been completed” there were

inserted, “or, if earlier the date on which in accordance with

regulation 17 of the Building (Approved Inspectors etc.)

Regulations 2010 the initial notice ceases to be in force”.

Requirement G2 applies only when a dwelling is—

(a) erected; or

(b) formed by a material change of use of a building

within the meaning of regulation 5(a) or (b).

The Requirement G2 and Regulation 36

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G2 WATER EFFICIENCY

Performance

In the Secretary of State’s view Requirement G2

will be met for new dwellings if:

a. the estimated consumption of wholesome

water resulting from the design of cold and

hot water systems (calculated in accordance

with the methodology set out in Appendix A

to this approved document and taking into

account the use of any alternative sources

of water provided in accordance with G1(2))

is not greater than the standard set by the

Secretary of State of 125 litres/person/day of

wholesome water or 110 litres/person/day

where the optional requirement applies;

b. the manner in which sanitary appliances and

white goods used in the design calculation

undertaken to demonstrate compliance with

paragraph (a) are provided and installed in the

dwelling takes account of the other provisions

in this approved document;

c. the manner in which any alternative sources

of water used in the design calculation

undertaken to demonstrate compliance with

paragraph (a) are supplied to the dwelling,

takes account of other provisions in this

approved document;

d. a record of the sanitary appliances and

white goods used in the water consumption

calculation and installed in the dwelling

is provided along with sufﬁcient other

information enabling building owners or

occupiers to maintain the building and its

services so as to maintain the water efﬁciency

of the building. In this context, relevant

white goods are washing machines and

dishwashers;

e. a record of the alternative sources of water

used in the water consumption calculation

and supplied to the dwelling is provided along

with sufﬁcient other information enabling

building owners or occupiers to maintain the

building and its services so as to maintain

the water efﬁciency of the building.

Where a building consists of more than one

dwelling (such as a block of ﬂats) it should be

designed so that the estimated consumption of

wholesome water resulting from the design of the

cold and hot water systems for each individual

dwelling should be no greater than the target.

General

2.1 The water used by sanitary appliances

and relevant white goods in a new dwelling

should be calculated using the manufacturer’s

declared value for water consumption of each

of those appliances and white goods.

2.2

The estimated water consumption of a

new dwelling should be calculated

in accordance

with the methodology set out in Appendix A,

referred to as the water efﬁciency calculator.

2.3

The estimated consumption of

wholesome water of a new dwelling should

be no more than 125 litres/person/day or

110 litres/person/day where the optional

requirement applies. This includes a ﬁxed

factor of water for outdoor use of 5 litres/

person/day.

2.4 Where alternative sources of water are to

be used in the dwelling design, this should be

reﬂected in the estimate of water use.

Fittings approach

2.5 As an alternative to calculating the water

consumption (as paragraph 2.2), a ﬁttings

approach that is based on the water efﬁciency

calculator methodology may be used.

2.6 Where the ﬁttings approach is used, the

water consumption of the ﬁttings provided must

not exceed the values in Table 2.1. If they do, the

water efﬁciency calculator must be completed

to demonstrate compliance. Similarly, where a

shower is not to be provided or where a waste

disposal unit, a water softener or water re-use

is to be provided the water efﬁciency calculator

must be completed.

Table 2.1 Maximum fittings

consumption

Water fitting Maximum consumption

WC 6/4 litres dual flush or

4.5 litres single flush

Shower 10 l/min

Bath 185 litres

Basin taps 6 l/min

Sink taps 8 l/min

Dishwasher 1.25 l/place setting

Washing machine 8.17 l/kilogram

2.7 Where the ﬁttings approach is used, the

notice given under regulation 37 should state

“Less than 125 litres/person/day using ﬁttings

approach”.

Guidance

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WATER EFFICIENCY G2

Optional requirement

2.8 The optional requirement only applies

where a condition that the dwelling should meet

the optional requirement is imposed as part of

the process of granting planning permission.

Where it applies, the estimated consumption

of wholesome water calculated in accordance

with the methodology in the water efﬁciency

calculator, should not exceed 110 litres/person/day.

2.9 The person carrying out the work must

inform the BCB where the optional requirement

applies.

2.10 As an alternative to calculating the water

consumption (as paragraph 2.8), a ﬁttings

approach that is based on the water efﬁciency

calculator methodology may be used.

2.11 Where the ﬁttings approach is used, the

water consumption of the ﬁttings provided must

not exceed the values in Table 2.2. If they do, the

water efﬁciency calculator must be completed

to demonstrate compliance. Similarly, where a

shower is not to be provided or where a waste

disposal unit, a water softener or water re-use

is to be provided the water efﬁciency calculator

must be completed.

2.12 Where the ﬁttings approach is used, the

notice given under regulation 37 should state

“Less than 110 litres/person/day using ﬁttings

approach”.

Table 2.2 Maximum fittings

consumption optional

requirement level

Water fitting Maximum consumption

WC 4/2.6 litres dual flush

Shower 8 l/min

Bath 170 litres

Basin taps 5 l/min

Sink taps 6 l/min

Dishwasher 1.25 l/place setting

Washing machine 8.17 l/kilogram

Notiﬁcation of water efﬁciency

calculation to the BCB

2.13 Where regulation 36 applies, regulation 37

of the Building Regulations and regulation 20(1)

and (4) of the Building (Approved Inspectors etc.)

Regulations require that a notice specifying the

calculated potential consumption of wholesome

water per person per day relating to the dwelling

as constructed be given to the appropriate BCB.

2.14 In most cases, this notice must be given

to the BCB no later than ﬁve days after the

completion of the building work. However,

where the BCB is an Approved Inspector and

the dwelling is occupied before completion,

the notice must be given no later than the day

that the initial notice ceases to be in force in

consequence of regulation 18 of the Building

(Approved Inspectors etc) Regulations when this

is earlier than ﬁve days after the completion of

the work.

2.15 It is permissible for the notice to be served

on the BCB electronically provided the BCB has

stated its willingness to receive the document by

those means and it is delivered to the electronic

address that the body has speciﬁed.

2.16 Local authorities are unlikely to be able

to give a completion certiﬁcate for the building

until the notice required under regulation 37 of

the Building Regulations has been received.

Approved Inspectors are unlikely to be able to

give a ﬁnal certiﬁcate until the equivalent notice

under regulation 20(1) and (4) of the Building

(Approved Inspectors etc.) Regulations has been

received.

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G3 HOT WATER SUPPLY AND SYSTEMS

This Approved Document deals with the following

Requirement from Part G of Schedule 1 to the

Building Regulations 2010.

Requirement Limits on application

G3. (1) There must be a suitable installation for the provision of

heated wholesome water or heated softened wholesome water to:

(a) any washbasin or bidet provided in or adjacent to a

room containing a sanitary convenience;

(b) any washbasin, bidet, fixed bath and shower in a

bathroom; and

(2) A hot water system, including any cistern or other vessel

that supplies water to or receives expansion water from a hot

water system, shall be designed, constructed and installed so as

to resist the effects of temperature and pressure that may occur

either in normal use or in the event of such malfunctions as may

reasonably be anticipated, and must be adequately supported.

(3) A hot water system that has a hot water storage vessel shall

incorporate precautions to:

(a) prevent the temperature of the water stored in the

vessel at any time exceeding 100˚C; and

(b) ensure that any discharge from safety devices is safely

conveyed to where it is visible but will not cause a danger to

persons in or about the building.

(4) The hot water supply to any fixed bath must be so designed and

installed as to incorporate measures to ensure that the temperature

of the water that can be delivered to that bath does not exceed 48˚C.

Requirement G3(3) does not apply to a system which heats or

stores water for the purposes only of an industrial process.

Requirement G3(4) applies only when a dwelling is—

(a) erected;

(b) formed by a material change of use within the meaning

of regulation 5(a) or (b).

The Requirement G3

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HOT WATER SUPPLY AND SYSTEMS G3

Performance

In the Secretary of State’s view Requirement

G3(1) will be met if:

a. the installation conveys hot water to the

sanitary appliances and locations speciﬁed

in the requirement without waste, misuse or

undue consumption of water; and

b. the water supplied is heated wholesome

water or heated softened water.

In the Secretary of State’s view Requirement

G3(2) will be met if all components of the hot

water system including any cistern that supplies

water to, or receives expansion water from the

hot water system continues to safely contain the

hot water:

a. during normal operation of the hot water

system;

b. following failure of any thermostat used to

control temperature; and

c. during operation of any of the safety devices

ﬁtted in accordance with paragraph G3(3).

In the Secretary of State’s view Requirement

G3(3) will be met for a hot water storage

system that has a vented storage vessel if:

a. the storage vessel has a suitable vent pipe

connecting the top of the vessel to a point

open to the atmosphere above the level of

the water in the cold water storage cistern

and over it; and,

b. in addition to any thermostat, either the heat

source, or the storage vessel is ﬁtted with a

device that will prevent the temperature of the

stored water at any time exceeding 100˚C; and

c. the hot water system has pipework that

incorporates a provision for the discharge

of hot water from the safety devices to an

appropriate place open to the atmosphere

where it will cause no danger to persons in

or about the building.

In the Secretary of State’s view Requirement

G3(3) will be met for a hot water system that has

an unvented storage vessel if:

a. the storage vessel has at least two

independent safety devices such as those

that release pressure and so prevent the

temperature of the stored water at any

time exceeding 100˚C in addition to any

thermostat; and

b. the hot water system has pipework that

incorporates a provision for the discharge of

hot water from safety devices to be visible

at some point and safely conveys it to an

appropriate place open to the atmosphere

where it will cause no danger to persons in

or about the building.

In the Secretary of State’s view Requirement

G3(4) will be met if:

the hot water outlet temperature is appropriate

for the appliance being served, and any device

to limit the maximum temperature that can be

supplied at the outlet can not be easily altered by

building users.

General

3.1 The delivered hot water can be considered

as heated wholesome water or heated softened

wholesome water where:

a. the cold water supply to the hot water system

is wholesome or softened wholesome; and

b. the installation complies with the requirements

of the Water Supply (Water Fittings) Regulations

1999 (SI 1999/1148 as amended).

3.2 The Water Supply (Water Fittings) Regulations

make provision for preventing contamination,

waste, misuse, undue consumption and

erroneous measurement of water supplied by

a water undertaker or licensed water supplier.

Guidance on the application of the Water Supply

(Water Fittings) Regulations can be found in the

Water Regulations Guide published by the Water

Regulations Advisory Scheme.

3.3 Attention is also drawn to the requirements

of the Gas Safety (Installation and Use)

Regulations 1994 (SI 1994/1886) for all gas

installation work.

3.4 Electrical work associated with hot water

systems should be carried out in accordance

with BS7671:2008 Requirements for electrical

installations (IEE Wiring Regulations 17th Edition).

3.5 For installations in dwellings and

associated buildings, attention is drawn to

Building Regulations 2010 Schedule 1 Part P

(Electrical safety – Dwellings) and to Approved

Document P.

3.6 For workplaces and premises controlled

in connection with a trade, business or other

undertaking, attention is also drawn to the HSC

publication Legionnaires’ Disease: Control of

Legionella Bacteria in Water Systems. Approved

code of practice and guidance. L8, Health and

Safety Commission 2000. ISBN 0 7176 1772 6.

3.7 Pipework should be designed and installed

in such a way as to minimise the transfer time

between the hot water storage system and hot

water outlets.

3.8 The safety requirements for hot water

systems used solely for supplying water for

industrial processes is contained in the Pressure

Systems Safety Regulations 2000 (SI 2000/128)

and further guidance is available in Safety of

pressure systems. Pressure Systems Safety

Regulations 2000. Approved Code of Practice

L122 HSE Books 2000. ISBN 0 7176 1767 X.

Guidance

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G3 HOT WATER SUPPLY AND SYSTEMS

Provision of hot water supply

3.9 The Requirement G3 only requires the

provision of a hot water supply to:

a. any washbasin provided in association

with a sanitary convenience in accordance

with G4(2);

b. any washbasin, bidet, ﬁxed bath or shower

in a bathroom in a dwelling or provided for

rooms for residential purposes, provided in

accordance with G5;

c. any sink in a food preparation area, provided

in accordance with G6.

There is no requirement under the Building

Regulations to provide hot water to other

washing facilities, but there may be such

requirements under other legislation (see

paragraphs 4.3, 4.4 and 6.4).

Design and installation of directly

or indirectly heated hot water

storage systems

General

3.10 Hot water storage systems should be

designed and installed in accordance with BS

6700:2006 + A1:2009 Speciﬁcation for design,

installation, testing and maintenance of services

supplying water for domestic use within buildings

and their curtilages or BS EN 12897:2006

Water supply. Speciﬁcation for indirectly heated

unvented (closed) storage water heaters.

3.11 Hot water storage vessels should conform to

BS 853-1:1996 Speciﬁcation for vessels for use in

heating systems. Caloriﬁers and storage vessels for

central heating and hot water supply, BS 1566-

1:2002 Copper indirect cylinders for domestic

purposes. Open vented copper cylinders.

Requirements and test methods, or BS 3198:1981

Speciﬁcation for copper hot water storage

combination units for domestic purposes or other

relevant national standards as appropriate.

Vented hot water storage systems

3.12 Vented hot water storage systems

should incorporate a vent pipe of an adequate

size, but not less than 19mm internal diameter,

connecting the top of the hot water storage

vessel to a point open to the atmosphere above

and over the level of the water in the cold water

storage cistern.

3.13 In addition to the vent pipe referred to

in 3.12 and any thermostat provided to control

the temperature of the stored water to a desired

temperature, vented hot water storage systems

should incorporate either:

a. for all direct heat sources, a non-self-resetting

energy cut-out to disconnect the supply of

heat to the storage vessel in the event of the

storage system overheating; and,

for all indirect heat sources, an overheat

cut-out to disconnect the supply of heat to

the storage vessel in the event of the stored

water overheating so that the temperature of

the stored water does not exceed 100°C; or

b. an appropriate safety device, for example,

a temperature relief valve or a combined

temperature and pressure relief valve to

safely discharge the water in the event of

signiﬁcant over heating.

3.14 Vent pipes should discharge over a cold

water storage cistern conforming to BS 417-

2:1987 Speciﬁcation for galvanized low carbon

steel cisterns, cistern lids, tanks and cylinders.

Metric units; or BS 4213:2004 Cisterns for

domestic use. Cold water storage and combined

feed and expansion (thermoplastic) cisterns up to

500 litres. Speciﬁcation; as appropriate.

3.15 The cold water storage cistern into which

the vent pipe discharges should be supported

on a ﬂat, level, rigid platform which is capable

of safely withstanding the weight of the cistern

when ﬁlled with water to the rim and fully

supporting the bottom of the cistern over the

whole of its area. The platform should extend a

minimum of 150mm in all directions beyond the

edge of the maximum dimensions of the cistern.

Note: Where an existing metal cistern is

replaced, or a plastic cistern is replaced by one

with larger dimensions, the existing support

should be upgraded, as necessary, with one in

accordance with paragraph 3.15.

3.16 The cistern should be accessible for

maintenance, cleaning and replacement.

Unvented hot water storage systems –

all systems

3.17 To minimize the danger from excessive

pressure, unvented hot water storage systems

should incorporate a minimum of two independent

safety devices. These shall be in addition to

any thermostat provided to control the desired

temperature of the stored water. The selection

of safety devices should take account of the

physical location of the devices, and the design,

conﬁguration, location of components and

performance characteristics of the system to

which they are attached.

3.18 An acceptable approach might consist of:

a. a non self-resetting energy cut-out to

disconnect the supply of heat to the storage

vessel in the event of the storage system

over-heating; and

b. a temperature relief valve or a combined

temperature and pressure relief valve to safely

discharge the water in the event of serious

over-heating.

Alternative approaches to this are acceptable

provided that they provide an equivalent degree

of safety.

Note: See 3.35 for suitability of devices for

primary thermal stores

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3.19 Water heaters with a capacity of 15 litres

or less that have appropriate safety devices for

temperature and pressure will generally satisfy

the requirement set out in G3(3).

Unvented hot water storage systems –

systems up to 500 litres capacity and 45kW

power input

3.20 Paragraphs 3.21 to 3.24 are in addition to

the provisions of 3.17 above.

3.21 If an indirect supply of heat to an unvented

hot water storage system incorporates a boiler,

the energy cut-out may be on the boiler.

3.22 Any unvented hot water storage system

up to 500 litres and less than 45kW should be in

the form of a proprietary hot water storage

system unit or package. The package and

components should be appropriate to the

circumstances in which they are used and should

satisfy an appropriate standard that will ensure

the requirements of regulation G3(2) and G3(3)

will be met (e.g. BS EN 12897:2006 Water Supply.

Speciﬁcation for indirectly heated unvented (closed)

hot water storage systems or BS 6700:2006 +

A1:2009 Design, installation, testing and

maintenance of services supplying water for

domestic use within buildings and their curtilages).

WARNING TO USER

a. Do not remove or adjust any component part of this unvented water heater; contact

the installer.

b. If this unvented water heater develops a fault, such as a ﬂow of hot water from the

discharge pipe, switch the heater off and contact the installer.

WARNING TO INSTALLER

a. This installation is subject to the Building Regulations.

b. Use only appropriate components for installation or maintenance.

Installed by:

Name ..............................................................................................................................................

Address ..........................................................................................................................................

Tel. No. ............................................................................................................................................

Completion date .............................................................................................................................

3.23 Any unvented hot water storage system

unit or package should be indelibly marked with

the following information:

a. the manufacturer’s name and contact details;

b. a model reference;

c. the rated storage capacity of the storage

water heater;

d. the operating pressure of the system and the

operating pressure of the expansion valve;

e. relevant operating data on each of the safety

devices ﬁtted; and

f. the maximum primary circuit pressure and

ﬂow temperature of indirect hot water

storage system units or packages.

3.24 In addition, the following warning should

be indelibly marked on the hot water storage

system unit or package so that it is visible after

installation:

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Unvented hot water storage systems –

systems over 500 litres capacity or over 45kW

power input

3.25 Paragraph 3.26 and 3.27 are in addition to

the provisions of 3.17 above.

3.26 Systems over 500 litres capacity will

generally be bespoke designs for speciﬁc

projects and as such are inappropriate for

approval by a third party accredited product

conformity certiﬁcation scheme. Where this is the

case, the unvented hot water storage system

should be designed to the safety requirements in

3.17 by an appropriately qualiﬁed engineer.

3.27 Any unvented hot water storage system

having a power input of more than 45kW, but

a capacity of 500 litres or less should be in

the form of a proprietary hot water storage

system unit or package. The package and

components should be appropriate to the

circumstances in which they are used and

should satisfy an appropriate standard that

will ensure the requirement of regulation G3(2)

and G3(3) will be met (e.g. BS EN 12897:2006

Water Supply. Speciﬁcation for indirectly heated

unvented (closed) hot water storage systems or

BS 6700:2006 + A1:2009 Design, installation,

testing and maintenance of services supplying

water for domestic use within buildings and

their curtilages).

Safety devices

Non-self-resetting energy cut-outs

3.28 Non-self-resetting energy cut-outs may

only be used where they would have the effect

of instantly disconnecting the supply of energy

to the storage vessel.

3.29 Non-self-resetting energy cut-outs should

conform to:

a. BS EN 60335-2-73:2003 Speciﬁcation for safety

of household and similar electrical appliances.

Particular requirements. Fixed immersion

heaters and BS EN 60730-2-9:2002

Automatic electrical controls for household

and similar use. Particular requirements for

temperature sensing control; or

b. BS EN 257:1992 Mechanical thermostats for

gas-burning appliances.

3.30 Where a non self-resetting energy cut-

out operates indirectly on another device (see

paragraph 3.18) to interrupt the supply of heat

(e.g. it is wired up to a motorised valve or some

other suitable device to shut off the ﬂow to the

primary heater), the energy cut-out should

comply with the relevant European Standard

(see paragraph 3.29) or the supplier or installer

should be able to demonstrate that the device

has equivalent performance to that set out in

relevant standards.

3.31 Where an electrical device is connected to

the energy cut-out, such as a relay or motorised

valve, the device should operate to interrupt the

supply of energy if the electrical power supply is

disconnected.

3.32 Where there is more than one energy cut-

out (see paragraph 3.35), each non-self-resetting

energy cut-out should be independent (e.g. each

should have a separate motorised valve and a

separate temperature sensor).

3.33 Where an energy cut-out is ﬁtted as set

out in paragraphs 3.13 a) or 3.18, each heat

source should have a separate non self-resetting

energy cut-out.

Temperature and pressure relief devices

3.34 Where relevant, appropriate pressure,

temperature or temperature and pressure-

activated safety devices should be ﬁtted in addition

to a safety device such as an energy cut-out.

3.35 Temperature relief valves and combined

temperature and pressure relief valves should

not be used in systems which have no provision

to automatically replenish the stored water (e.g.

unvented primary thermal storage vessels). In

such cases there should be a second non-self-

resetting energy cut-out independent of the one

provided in accordance with paragraph 3.18(a).

3.36 Temperature relief valves should conform

to relevant national standards such as BS 6283–

2:1991 Safety and control devices for use in hot

water systems. Speciﬁcations for temperature

relief valves for pressures from 1 bar to 10 bar.

Combined temperature and pressure relief

valves should conform to BS EN 1490:2000

Building valves. Combined temperature and

pressure relief valves. Tests and Requirements.

3.37 Temperature relief valves (see paragraph

3.18) should be sized to give a discharge rating

at least equal to the total power input to the

hot water storage system, when measured in

accordance with Appendix F of BS 6283-2:1991

or BS EN 1490:2000.

3.38 Temperature relief valve(s) or combined

temperature and pressure relief valve(s) (see

paragraph 3.18) should be located directly on the

storage vessel, such that the stored water does

not exceed 100˚C.

3.39 In hot water storage system units

and packages, the temperature relief valve(s)

(see paragraph 3.18) should be:

a. factory ﬁtted and should not be disconnected

other than for replacement; and

b. not relocated in any other device or ﬁtting

installed.

3.40 The safety and performance of an

unvented system is dependent on the choice of

system and safety devices appropriate for the

location and correct installation of the system.

Building owners and occupiers should therefore

take care to choose installers who have the

necessary skills to carry out this work. These

skills can be demonstrated for example, by

registration with a competent person scheme for

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this type of work or by the holding of a current

registered operative skills certiﬁcation card for

unvented hot water systems.

3.41 The installation of an unvented system is

notiﬁable building work which must be notiﬁed to

the BCB before work commences. The BCB may

then check to make sure the work is safe and

meets current energy efﬁciency requirements.

3.42 If the installer is registered with a

competent person scheme for the installation

of unvented hot water systems it will not be

necessary for the work to be notiﬁed in advance

to the BCB. Installers registered with such

schemes will self-certify that the work complies

with all relevant requirements in the Building

Regulations and the building owner/occupier

will be given a building regulations certiﬁcate

of compliance which is usually issued by the

competent person scheme operator.

Electric water heating

3.43 Electric ﬁxed immersion heaters should

comply with the provisions of BS EN 60335-

2-73:2003 Household and similar electrical

appliances. Safety. Particular requirements for

ﬁxed immersion heaters.

3.44 Electric instantaneous water heaters

should comply with the provisions of BS EN

60335-2-35:2002 Speciﬁcation for safety of

household and similar electrical appliances.

3.45 Electric storage water heaters should

comply with the provisions of BS EN 60335-

2-21:2003 Household and similar electrical

appliances. Safety. Particular requirements for

storage water heaters.

Solar water heating

3.46 Factory-made solar water heating

systems should comply with the provisions of

BS EN 12976-1:2006 Thermal solar systems and

components. Factory made systems. General

requirements.

3.47 Other solar water heating systems should

comply with the provisions of prEN/TS 12977-

1:2008 Thermal solar systems and components.

Custom built systems. General requirements for

solar water heaters and combi systems, or BS

5918:1989 British Standard Code of Practice for

Solar heating systems for domestic hot water

as appropriate. Further guidance is available in

CIBSE Guide G, Public Health Engineering and

CIBSE technical guide Solar Heating Design

and Installation.

3.48 Where solar water heating systems are used,

an additional heat source should be available.

Note: The additional heat source should be

used, when necessary, to maintain the water

temperature to restrict microbial growth.

3.49 As some solar hot water systems operate

at elevated temperatures and pressures, and

so all components should be rated to the

appropriate temperatures and pressures.

Discharge pipes from safety devices

Discharge pipe D1

3.50 Safety devices such as temperature relief

valves or combined temperature and pressure

relief valves (see paragraphs 3.13 or 3.18) should

discharge either directly or by way of a manifold

via a short length of metal pipe (D1) to a tundish.

3.51 The diameter of discharge pipe (D1)

should be not less than the nominal outlet size of

the safety device, e.g. temperature relief valve.

3.52 Where a manifold is used it should be

sized to accept and discharge the total discharge

from the discharge pipes connected to it.

3.53 Where valves other than a temperature

and pressure relief valve from a single unvented

hot water system discharge by way of the same

manifold that is used by the safety devices, the

manifold should be factory ﬁtted as part of the

hot water storage system unit or package.

Tundish

3.54 The tundish should be vertical, located

in the same space as the unvented hot water

storage system and be ﬁtted as close as

possible to, and lower than, the safety device,

with no more than 600mm of pipe between the

valve outlet and the tundish (see Diagram 1).

Note: To comply with the Water Supply (Water

Fittings) Regulations, the tundish should

incorporate a suitable air gap.

3.55 Any discharge should be visible at the

tundish. In addition, where discharges from

safety devices may not be apparent, e.g. in

dwellings occupied by people with impaired

vision or mobility, consideration should be

given to the installation of a suitable safety

device to warn when discharge takes place,

e.g. electronically operated.

Discharge pipe D2

3.56 The discharge pipe (D2) from the tundish

should:

a. have a vertical section of pipe at least 300mm

long below the tundish before any elbows or

bends in the pipework (see Diagram 1); and

b. be installed with a continuous fall of at least

1 in 200 thereafter.

3.57 The discharge pipe (D2) should be

made of:

a. metal; or

b. other material that has been demonstrated

to be capable of safely withstanding

temperatures of the water discharged and is

clearly and permanently marked to identify

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the product and performance standard (e.g.

as speciﬁed in the relevant part of BS 7291-

1:2006 Thermostatic pipes and ﬁttings for

hot and cold water for domestic purposes

and heating installations in buildings.

General requirements).

3.58 The discharge pipe D2 should be at least

one pipe size larger than the nominal outlet size

of the safety device unless its total equivalent

hydraulic resistance exceeds that of a straight

pipe 9m long, i.e. for discharge pipes between

9m and 18m the equivalent resistance length

should be at least two sizes larger than the

nominal outlet size of the safety device; between

18 and 27m at least 3 sizes larger, and so on;

bends must be taken into account in calculating

the ﬂow resistance. See Diagram 1, Table 3.1 and

the worked example.

Note: An alternative approach for sizing

discharge pipes would be to follow Annex

D, section D.2 of BS 6700:2006 + A1:2009

Speciﬁcation for design, installation, testing

and maintenance of services supplying water

for domestic use within buildings and their

curtilages.

Diagram 1 Typical discharge pipe arrangement

600mm maximum

Discharge pipe (D2) from tundish,

with continuous fall. See 3.56, Table 3.1

and worked example

Discharge below

fixed grating

(3.61 gives

alternative points

of discharge)

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Table 3.1 Sizing of copper discharge pipe ‘D2’ for common temperature relief valve

outlet sizes

Valve outlet size

Minimum size of

discharge pipe D1*

Minimum size of

discharge pipe D2*

from tundish

Maximum resistance

allowed, expressed

as a length of straight

pipe (i.e. no elbows

or bends)

Resistance created by

each elbow or bend

G½ 15mm 22mm

28mm

35mm

Up to 9m

Up to 18m

Up to 27m

0.8m

1.0m

1.4m

G¾ 22mm 28mm

35mm

42mm

Up to 9m

Up to 18m

Up to 27m

1.0m

1.4m

1.7m

G1 28mm 35mm

42mm

54mm

Up to 9m

Up to 18m

Up to 27m

1.4m

1.7m

2.3m

*see 3.51 and 3.58 and Diagram 1

Note: The above table is based on copper tube. Plastic pipes may be of different bore and resistance.

Sizes and maximum lengths of plastic should be calculated using data prepared for the type of pipe being used.

Worked example:

The example below is for a G½ temperature relief valve with

a discharge pipe (D2) having 4 No. 22mm elbows and length of

7m from the tundish to the point of discharge.

From Table 3.1:

Maximum resistance allowed for a straight length of 22mm

copper discharge pipe (D2) from a G½ temperature relief

valve is: 9.0m

Subtract the resistance for 4 No. 22mm elbows at 0.8m each

= 3.2m

Therefore the maximum permitted length equates to 5.8m

which, is less than the actual length of 7m therefore calculate

the next largest size.

Maximum resistance allowed for a straight length of 28mm

copper discharge pipe (D2) from a G½ temperature relief

valve is: 18m

Subtract the resistance for 4 No. 28mm elbows at 1.0m each = 4m

Therefore the maximum permitted length equates to: 14m

As the actual length is 7m, a 28mm (D2) copper pipe will

be satisfactory.

3.59 Where a single common discharge pipe

serves more than one system, it should be

at least one pipe size larger than the largest

individual discharge pipe (D2) to be connected.

3.60 The discharge pipe should not be

connected to a soil discharge stack unless it can

be demonstrated that the soil discharge stack is

capable of safely withstanding temperatures of

the water discharged, in which case, it should:

a. contain a mechanical seal, not incorporating

a water trap, which allows water into the

branch pipe without allowing foul air from the

drain to be ventilated through the tundish;

b. be a separate branch pipe with no sanitary

appliances connected to it;

c. if plastic pipes are used as branch pipes

carrying discharge from a safety device, they

should be either polybutalene (PB) or cross-

linked polyethylene (PE-X) complying with

national standards such as Class S of BS

7291-2:2006 or Class S of BS 7291-3:2006

respectively; and

d. be continuously marked with a warning that

no sanitary appliances should be connected

to the pipe.

Notes:

1. Plastic pipes should be joined and assembled

with ﬁttings appropriate to the circumstances

in which they are used as set out in

BS EN ISO 1043-1:2002 Plastics. Symbols

and abbreviated terms. Basic polymers and

their special characteristics.

2. Where pipes cannot be connected to the

stack it may be possible to route a dedicated

pipe alongside or in close proximity to the

discharge stack

Termination of discharge pipe

3.61 The discharge pipe (D2) from the tundish

should terminate in a safe place where there is no

risk to persons in the vicinity of the discharge.

3.62 Examples of acceptable discharge

arrangements are:

a. to a trapped gully with the end of the pipe below

a ﬁxed grating and above the water seal;

b. downward discharges at low level; i.e. up to

100mm above external surfaces such as car

parks, hard standings, grassed areas etc.

are acceptable providing that a wire cage or

similar guard is positioned to prevent contact,

whilst maintaining visibility; and,

c. discharges at high level: e.g. into a metal

hopper and metal downpipe with the end

of the discharge pipe clearly visible or

onto a roof capable of withstanding high

temperature discharges of water and 3 m

from any plastic guttering system that would

collect such discharges.

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3.63 The discharge would consist of high

temperature water and steam. Asphalt, rooﬁng

felt and non-metallic rainwater goods may be

damaged by such discharges.

Prevention of excessive temperatures

3.64 Where the operating temperature of

domestic hot water in the storage vessel in a

dwelling is capable of exceeding 80°C under

normal operating conditions (a situation that may

occur in vessels used as heat stores and those

connected to solar heat collectors or solid fuel

boilers that do not have intervening controls

between the boiler and the vessel containing

the hot water) the outlet from the storage vessel

should be ﬁtted with a device, such as an in-line

hot water supply tempering valve in accordance

with BS EN 15092:2008 Building Valves. In-line

hot water tempering valves, to ensure that the

temperature supplied to the domestic hot water

distribution system does not exceed 60°C.

Prevention of scalding

3.65 The hot water supply temperature to a

bath should be limited to a maximum of 48°C

by use of an in-line blending valve or other

appropriate temperature control device, with

a maximum temperature stop and a suitable

arrangement of pipework.

3.66 The acceptability of in-line blending valves

can be demonstrated by compliance with the

relevant European Standard such as BS EN

1111:1999 Sanitary tapware. Thermostatic mixing

valves (PN 10). General technical speciﬁcation

or BS EN 1287:1999 Sanitary tapware. Low

pressure thermostatic mixing valves. General

technical speciﬁcations to demonstrate that

the maximum temperature of 48°C cannot be

exceeded in operation and that the product

will fail-safe (i.e. not discharge water above

the maximum temperature). Such valves should

not be easily altered by building users.

3.67 In-line blending valves and composite

thermostatic mixing valves should be compatible

with the sources of hot and cold water that

serve them.

3.68 The length of supply pipes between in-line

blending valves and outlets should be kept to

a minimum in order to prevent the colonisation

of waterborne pathogens. If intermittent use

of the bath is anticipated, provision should be

made for high temperature ﬂushing to allow

pasteurisation of the pipes and outlet ﬁttings.

Such events should be managed to prevent the

risk associated with inadvertent use.

Notes:

1. Further guidance on the use of in-line

blending valves can be found in BRE

Information paper IP14/03 Preventing hot

water scalding in bathrooms: using TMVs

2. In some buildings, e.g. care homes, in-line

blending valves would need to meet the

additional performance standards set out

in NHS Estates Model speciﬁcation D 08

Installation

3.69 Good workmanship is essential.

Workmanship should be in accordance with

appropriate standards such as BS 8000–15:1990

Workmanship on Building Sites Code of practice

for hot and cold water services (domestic scale).

Commissioning of ﬁxed building

services

3.70 Water heaters require the input of energy

to raise the temperature of water. It is therefore

necessary to ensure their efﬁciency by proper

installation and commissioning.

3.71 Fixed building services, including

controls, should be commissioned by testing and

adjusting as necessary to ensure that they use

no more fuel and power than is reasonable in the

circumstances.

3.72 Commissioning means the advancement

of these systems from the state of static completion

to working order to achieving compliance with

Part L. For each system it includes setting-to-

work, regulation (that is testing and adjusting

repetitively) to achieve the speciﬁed performance,

the calibration, setting up and testing of the

associated automatic control systems, and

recording of systems and the performance test

results that have been accepted as satisfactory.

3.73 Not all ﬁxed building services will need

to be commissioned. For example, with some

systems it is not possible as the only controls

are ‘on’ and ‘off’ settings. In other cases

commissioning would be possible but in the

speciﬁc circumstances would have no effect

on energy use.

3.74 Where commissioning is carried out it

must be done in accordance with a procedure

approved by the Secretary of State. For new and

existing dwellings the approved procedure for hot

water systems is set out in the Domestic Heating

Compliance Guide; for buildings other than

dwellings in CIBSE Commissioning Code M.

3.75 Commissioning must be carried out in

such a way as not to prejudice compliance with

any applicable health and safety requirements.

3.76 Commissioning is often carried out by

the person who installs the system. Sometimes

it may be carried out by a subcontractor or by a

specialist ﬁrm. It is important that whoever carries

it out follows the relevant approved procedure in

doing so.

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Notice of completion of

commissioning

3.77 The Building Regulations (regulation

20C(2)) and the Building (Approved Inspectors

etc.) Regulations (regulation 20(1) and (6)) require

that the person carrying out the work shall give

a notice to the relevant BCB that commissioning

has been carried out according to a procedure

approved by the Secretary of State, unless

testing and adjustment is not possible, or would

not affect the energy efﬁciency of the ﬁxed

building service.

3.78 Where the work is carried out in

accordance with a building notice, or full plans,

or an initial notice or amendment notice, the

notice of commissioning should be given not

more than 5 days after the completion of the

commissioning work. In other cases, for example

where work is carried out by a person registered

with a competent person scheme, it must be given

not more than 30 days after the completion of work.

3.79 Where the installation of ﬁxed building

services which require commissioning is carried

out by a person registered with a competent

person scheme the notice of commissioning will

be given by that person.

3.80 Until the BCB receives notice of

commissioning it is unlikely to be satisﬁed that

Part G has been complied with and consequently

is unlikely to be able to give a completion/ﬁnal

certiﬁcate.

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G4 SANITARY CONVENIENCES AND WASHING FACILITIES

This Approved Document deals with the following

Requirement from Part G of Schedule 1 to the

Building Regulations 2010.

Requirement Limits on application

Sanitary conveniences and washing facilities

G4 (1) Adequate and suitable sanitary conveniences must

be provided in rooms provided to accommodate them or in

bathrooms.

(2) Adequate hand washing facilities must be provided in:

(a) rooms containing sanitary conveniences; or

(b) rooms or spaces adjacent to rooms containing sanitary

conveniences.

(3) Any room containing a sanitary convenience, a bidet,

or any facility for washing hands provided in accordance with

paragraph (2)(b), must be separated from any kitchen or any

area where food is prepared.

The Requirement G4

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Approved Document G

Sanitation, hot water safety and water efﬁciency

SANITARY CONVENIENCES AND WASHING FACILITIES G4

Performance

In the Secretary of State’s view Requirement G4

will be met if:

a. Sanitary conveniences of the appropriate

type for the sex and age of the persons

using the building are provided in sufﬁcient

numbers, taking into account the nature of

the building; and

b. hand washing facilities are provided in, or

adjacent to, rooms containing sanitary

conveniences and are sited, designed and

installed so as not to be prejudicial to health.

General

4.1 Attention is also drawn to the requirements

for accessible sanitary conveniences and

hand washing facilities of Part M (Access to and

use of buildings) of Schedule 1 to the Building

Regulations 2010 and to Approved Document M

and to the Regulators’ performance speciﬁcation

made under the Water Supply (Water Fittings)

Regulations 1999 (SI 1999/1148 as amended)

for WC suites.

4.2 Requirement for ventilation is in Part

F (Ventilation) of Schedule 1 to the Building

Regulations 2010. Guidance on ventilation of

sanitary accommodation is given in Approved

Document F.

4.3 The number, type and siting of sanitary

conveniences, including separate provision for

men and women, for staff in workplaces are also

subject to the Workplace (Health, Safety and

Welfare) Regulations 1992. Attention is drawn

to the Approved Code of Practice issued with

respect to those Regulations.

4.4 Further guidance on washbasins

associated with sanitary conveniences may be

found in the Food Standards Agency’s Code of

Practice Food hygiene – a guide for businesses.

4.5 Guidance on the selection, installation and

maintenance of sanitary appliances including

composting toilets may be found in BS 6465-

3:2006 Sanitary installations. Code of practice

for the selection, installation and maintenance

of sanitary and associated appliances.

4.6 Where hot and cold taps are provided

on a sanitary appliance, the hot tap should be

on the left.

Scale of provision and layout

in dwellings

4.7 Any dwelling (house or ﬂat) should have at

least one sanitary convenience and associated

hand washing facility. This will include a WC

provided in accordance with requirement M4(1)

(Sanitary conveniences in dwellings) of Schedule

1 to the Building Regulations 2010 and with

Approved Document M, Volume 1.

Note: Requirement M4(1) requires that a sanitary

convenience should be located in the principal/

entrance storey of a dwelling.

4.8 Where additional sanitary conveniences

are provided, each should have an associated

hand washing facility.

4.9 To allow for basic hygiene, hand washing

facilities should be located in:

a. the room containing the sanitary

convenience; or

b. an adjacent room or place that provides the

sole means of access to the room containing

the sanitary convenience (provided that it is

not used for the preparation of food).

4.10 A place containing a sanitary

convenience and/or associated hand washing

facilities should be separated by a door from any

place used for the preparation of food (including

a kitchen) (see Diagrams 2 and 3).

Note: In dwellings, a room containing both a

sanitary convenience and a basin for hand

washing does not need a separation lobby

between this room and a kitchen or food

preparation area (Diagram 2). The layout for

a room containing a sanitary convenience

only should be such that the room or space

containing its associated hand washing facilities

is accessed before entry to a food preparation

area, and is separated from that area by a door

(Diagram 3).

4.11 Guidance on the provision of activity

space around sanitary appliances is given in

BS 6465-2:1996 Sanitary installations. Code

of practice for space requirements for sanitary

appliances.

Guidance

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G4 SANITARY CONVENIENCES AND WASHING FACILITIES

Diagram 2 Separation between hand washbasin/WC and food preparation area –

single room

Food preparation

area

See para 4.10

Diagram 3 Separation between hand washbasin/WC and food preparation area –

two rooms

Food preparation

area

See para 4.10

Scale of provision and layout in

buildings other than dwellings

4.12 The Workplace (Health, Safety and

Welfare) Regulations 1992 require that a

minimum number of sanitary conveniences

must be provided in workplaces. The Approved

Code of Practice (ACOP) that supports those

Regulations sets out how to calculate that

minimum requirement (guidance on those

minimum numbers can be found at http://www.

hse.gov.uk/pubns/indg293.pdf).

4.13 Part M of Schedule 1 to the Building

Regulations 2010 sets out requirements relating

to access to and use of buildings. Approved

Document M provides guidance on the provision

of suitable sanitary accommodation. Such

accommodation may form part of the total

number of sanitary conveniences provided

within a building.

4.14 Further guidance on the provision of sanitary

conveniences can be found in BS 6465-1:2006

+ A1:2009 Sanitary installations. Code of practice

for the design of sanitary facilities and scales of

provision of sanitary and associated appliances. This

may be used for those building types not set out

in paragraph 4.12 above or for those workplaces

where the applicant wishes to provide more than the

minimum recommended in the Approved Code of

Practice, for example, to deliver equivalent provision

for men and women.

4.15 A sanitary convenience may be

provided in:

a. a self-contained room which also contains

hand washing facilities;

b. in a cubicle with shared hand washing

facilities located in a room containing a

number of cubicles; or

c. in a self-contained room with hand washing

facilities provided in an adjacent room.

4.16 Urinals, WC cubicles and hand washing

facilities may be in the same room.

4.17 A place containing a sanitary

convenience and/or associated hand washing

facilities should be separated by a door from any

place used for the preparation of food (including

a kitchen).

Note: For workplaces, the Workplace (Health,

Safety and Welfare) Regulations 1992 apply to

the separation of a place containing a sanitary

convenience and/or associated hand washing

facilities and a workplace.

4.18 Guidance on the provision of activity

space around sanitary appliances is given in

BS 6465-2:1996 Sanitary installations. Code

of practice for space requirements for sanitary

appliances.

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Approved Document G

Sanitation, hot water safety and water efﬁciency

SANITARY CONVENIENCES AND WASHING FACILITIES G4

Chemical and composting toilets

4.19 Chemical toilets or composting toilets may

be used where:

a. suitable arrangements can be made for

the disposal of the waste either on or off the

site; and

b. the waste can be removed from the premises

without carrying it through any living space

or food preparation areas (including a

kitchen); and

c. no part of the installation would be installed

in any places where it might be rendered

ineffective by the entry of ﬂood water.

4.20 There are currently no British or European

standards for composting toilets. Appropriate

guidance can be found in ANSI/NSF 41:2005

as amended by Addendum 1:2007 Non-liquid

saturated treatment system.

4.21 Composting toilets should not be

connected to an energy source other than

for purposes of ventilation or sustaining the

composting process.

Discharges to drains

Note: See Approved Document for requirement

H1 Sanitary pipework and drainage for guidance

on provision for traps, branch discharge pipes,

discharge stacks and foul drains.

4.22 Any WC ﬁtted with ﬂushing apparatus

should discharge to an adequate system of

drainage.

4.23 A urinal ﬁtted with ﬂushing apparatus

should discharge through a grating, a trap

or mechanical seal and a branch pipe to a

discharge stack or a drain.

4.24 A WC ﬁtted with a macerator and pump

may be connected to a small bore drainage

system discharging to a discharge stack if:

a. there is also access to a WC discharging

directly to a gravity system; and

b. the macerator and pump meets the

requirements of BS EN 12050-1:2001

Wastewater lifting plants for buildings and

sites. Principles of construction and testing.

Lifting plants for wastewater containing faecal

matter or BS EN 12050-3:2001 Wastewater

lifting plants for buildings and sites. Principles

of construction and testing. Lifting plants for

wastewater containing faecal matter for

limited applications.

Note: Where greywater recycling is used, lower

overall ﬂows are to be expected and this should

be taken into account in drain design. This is

particularly relevant at the head of the drain where

only one building is connected to the drain.

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Sanitation, hot water safety and water efﬁciency Approved Document G

G5 BATHROOMS

This Approved Document deals with the following

requirement from Part G of Schedule 1 to the

Building Regulations 2010.

Requirement Limits on application

Bathrooms

G5 A bathroom must be provided containing a wash basin and

either a fixed bath or a shower.

Requirement G5 applies only to dwellings and to buildings

containing one or more rooms for residential purposes.

The Requirement G5

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Sanitation, hot water safety and water efﬁciency

BATHROOMS G5

Performance

In the Secretary of State’s view Requirement G5

will be met if a bathroom is provided containing

a ﬁxed bath or shower, and a washbasin.

General

5.1 The Water Supply (Water Fittings) Regulations

1999 (SI 1999/1148) make provisions for

appropriate backﬂow protection on taps

including mixer ﬁttings and hose connections.

5.2 Requirements for ventilation are in Part F

of Schedule 1 to the Building Regulations 2010

(Ventilation). Guidance on ventilation of sanitary

accommodation is given in Approved

Document F.

5.3 Requirements for electrical safety are

given in Part P of Schedule 1 to the Building

Regulations 2010 (Electrical safety). Guidance

is given in Approved Document P.

5.4 Guidance on the selection, installation and

maintenance of sanitary appliances may be

found in BS 6465-3:2006 Sanitary installations.

Code of practice for the selection, installation and

maintenance of sanitary and associated appliances.

5.5 Where hot and cold taps are provided on

a sanitary appliance, the hot tap should be on

the left.

Scale of provision and layout in

dwellings

5.6 Any dwelling (house or ﬂat) must have at

least one bathroom with a ﬁxed bath or shower,

and a washbasin.

5.7 Guidance on the provision of activity

space around sanitary appliances is given in

BS 6465-2:1996 Sanitary installations. Code

of practice for space requirements for sanitary

appliances.

Scale of provision and layout in

buildings with rooms for residential

purposes

5.8 The number of ﬁxed baths or showers

and washbasins in buildings with rooms for

residential purposes should be in accordance

with BS 6465-1:2006 and A1:2009 Sanitary

installations. Code of practice for the design

of sanitary facilities and scales of provision of

sanitary and associated appliances.

Discharges to drains

Note: See Approved Document for Requirement

H1 Sanitary pipework and drainage for guidance

on provision for traps, branch discharge pipes,

discharge stacks and foul drains.

5.9 Any sanitary appliance used for personal

washing should discharge through a grating, a

trap and a branch discharge pipe to an adequate

system of drainage.

5.10 A sanitary appliance used for personal

washing ﬁtted with a macerator and pump may

be connected to a small bore drainage system

discharging to a discharge stack if:

a. there is also access to washing facilities

discharging directly to a gravity system; and

b. the macerator and pump meets the

requirements of BS EN 12050-2:2001

Wastewater lifting plants for buildings and

sites. Principles of construction and testing.

Lifting plants for faecal-free wastewater.

Guidance

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Sanitation, hot water safety and water efﬁciency Approved Document G

G6 FOOD PREPARATION AREAS

This Approved Document deals with the following

requirement from Part G of Schedule 1 to the

Building Regulations 2010.

Requirement Limits on application

Food preparation areas

G6 A suitable sink must be provided in any area where food

is prepared.

The Requirement G6

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Sanitation, hot water safety and water efﬁciency

FOOD PREPARATION AREAS G6

Performance

In the Secretary of State’s view Requirement G6

will be met if a sink is provided in any place used

for the preparation of food (including a kitchen).

Where a dishwasher is provided in a separate

room, an additional sink need not be provided

in that room.

Scale of provision in dwellings

6.1 A sink should be provided in any kitchen

or place used for the preparation of food.

6.2 Where a dishwasher is provided in a

separate room that is not the principal place for

the preparation of food, an additional sink need

not be provided in that room.

Scale of provision in buildings other

than dwellings

6.3 In all buildings other than dwellings,

there should be at least the same provision as

described in 6.1.

6.4 In buildings where the Food Hygiene

(England) Regulations 2006 (SI 2006/14) and

the Food Hygiene (Wales) Regulations 2006

(SI 2006/31 W5) apply, separate hand washing

facilities may be needed. This is in addition to

any hand washing facilities associated with

WCs in accordance with Requirement G4.

Discharges to drains

Note: See Approved Document for Requirement

H1 Sanitary pipework and drainage for guidance

on provision for traps, branch discharge pipes,

discharge stacks and foul drains.

6.5 Any sink should discharge through a

grating, a trap and a branch discharge pipe to

an adequate system of drainage.

Guidance

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Sanitation, hot water safety and water efﬁciency Approved Document G

Appendix A – Water efficiency calculator

for new dwellings

The water efﬁciency calculation

methodology

A1 This appendix sets out the water efﬁciency

calculation methodology for assessing the

whole house potable water consumption in new

dwellings. The calculation methodology is to be

used to assess compliance against the water

performance targets in Regulation 36 as set out

below. It is not a design tool for water supply

and drainage systems. It is also not capable of

calculating the actual potable water consumption

of a new dwelling. Behaviour and changing

behaviour can also have an effect on the amount

of potable water used throughout a home.

Performance target

Maximum calculated

consumption

of potable water

(litres/person/day)

Regulation 36 para (2)a 125

Regulation 36 optional

requirement para (2)b

110

A2 The calculation methodology requires

the use of water consumption ﬁgures provided

from manufacturers’ product details. Before the

assessment can be carried out, ﬁgures will need

to be collected from manufacturers’ product

information to determine the consumption of

each terminal ﬁtting, including:

a. WCs

i. Flushing capacity for the WC suite

including consumption at full and part

ﬂush for dual ﬂush WCs.

ii. Where multiple WCs are speciﬁed with

various ﬂushing capacities, the average

effective ﬂushing volume must be used as

set out in paragraphs A8 and A11.

b. Bidets

i. Bidets are excluded from the water

efﬁciency calculator for new dwellings

due to their minimal water consumption,

and although there is insufﬁcient research

to quantify this consumption, anecdotal

evidence shows that there is evidence

that bidets often displace other water

consumption rather than increase

consumption.

c. Taps

i. Flow rate of each tap, at full ﬂow rate in

litres per minute measured at a dynamic

pressure of 3±0.2 bar (0.3±0.02 MPa)

for high pressure (Type 1) taps, or at

a dynamic pressure of 0.1±0.02 bar

(0.01±0.002 MPa) for low pressure

(Type 2) taps (BS EN 200:2008, sanitary

tapware, single taps and combination

taps for supply systems of type 1 and 2.

General technical speciﬁcations) including

any reductions achieved with ﬂow

restrictions.

ii. Where multiple taps are to be provided

(e.g. separate hot and cold taps) the

ﬂow rate of each tap will be needed in

order to calculate an average ﬂow rate in

accordance with paragraphs A8 to A10.

iii. For ‘click taps’ and other taps with a

‘water break’, the manufacturer’s stated

full ﬂow rate should be used to perform

calculations (measured as described

above). Do not use the ﬂow rate at the

break point. A factor for percentage of

ﬂow rate is already assumed within the

use factor for taps. There is currently no

research to provide a separate use factor

for ‘click taps’ so a standard use factor is

applied.

iv. Taps on baths should not be included in

the calculation as the water consumption

from bath taps is taken account of in the

use factor for baths.

d. Baths

i. Total capacity of the bath to overﬂow,

in litres (excluding displacement, this

is already included in the use factor for

baths).

ii. Where multiple baths are speciﬁed with

various capacities, the average must be

used as set out in paragraphs A8 to A10.

iii. Spa hot tubs are not included in the water

efﬁciency calculator as they are generally

not ﬁlled on a daily basis and their water

consumption over a year is minimal.

e. Dishwashers

i. Litres per place setting derived from the

value quoted on the EU Energy Label,

i.e. annual water use 8(280=number of

place settings).

ii. Where no dishwasher is to be provided

and therefore consumption ﬁgures are

unknown, a ﬁgure of 1.25 litres per place

setting must be assumed.

iii. Where multiple dishwashers are speciﬁed

with various consumptions, the average

must be used as set out in paragraphs

A8 to A10.

f. Washing machines

i. Litres per kilogram of dry load derived

from the value quoted on the EU Energy

Label, i.e. annual water use 8(220=

capacity in kg).

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APPENDIX A – WATER EFFICIENCY CALCULATOR FOR NEW DWELLINGS G

ii. Where no washing machine is to be

provided and therefore consumption

ﬁgures are unknown, a ﬁgure of 8.17 litres

per kilogram must be assumed.

iii. Where multiple washing machines are

speciﬁed with various consumptions,

the average must be used as set out in

paragraphs A8 to A10.

g. Showers

i. Flow rate of each shower at the outlet

using cold water (T ) 30˚C), in litres per

minute measured at a dynamic pressure

of 3±0.2 bar (0.3±0.02 MPa) for high

pressure (Type 1) supply systems, or

at a dynamic pressure of 0.1±0.05 bar

(0.01±0.005 MPa) for low pressure (Type

2) supply systems (BS EN 1112:2008,

Sanitary tapware. Shower outlets for

sanitary tapware for water supply

systems type 1 and 2. General technical

speciﬁcations).

ii. Where multiple showers are speciﬁed with

various ﬂow rates, the average must be

used as set out in paragraphs A8 to A10.

h. Water softeners (where present)

i. Percentage of total capacity used per

regeneration cycle.

ii. Water consumed per regeneration cycle

(litres).

iii. Average number of regeneration cycles

per day.

iv. Number of occupants (based on two

occupants in the ﬁrst bedroom and

one occupant per additional bedroom

assuming two occupants in studio ﬂats).

v. Water softeners that do not have a water

consumption such as electromagnetic

types, are not included in the calculation.

i. Waste disposal units (where present)

i. Where present, a standard consumption

of 3.08 litres per person per day must be

assumed.

j. External taps

i. Flow rates of external taps are not

included in the calculation as a ﬁxed

allowance of ﬁve litres per person per day

is assumed for external water use.

A3 In some cases rainwater harvesting and

greywater recycling may be used as a means of

reducing water consumption to achieve higher

water efﬁciency performance levels. This may

be needed where options for improving the

efﬁciency of terminal ﬁttings (taps, WCs etc.)

have been maximised and further savings are still

needed:

a. Greywater (in accordance with BS 8525)

i. Manufacturer or system designer details

on the percentage of used water to be

recycled, taking into account the storage

capacity of the system.

ii. The volume of recycled water collected

from waste bath, shower and washhand

basin, dishwasher and washing machine

usage, with the volume collected

calculated in accordance with Table A1 or

Tables A4.3, A4.4 and A4.5.

iii. The consumption of ﬁttings where

greywater is to be used in accordance

with Table A1 which can include WCs and

washing machines or Tables A4.1 and

A4.2 where greywater is just being used

in a proportion of ﬁttings.

b. Rainwater (in accordance with BS 8515)

i. Collection area

ii. Yield co-efﬁcient and hydraulic ﬁlter

efﬁciency

iii. Rainfall (average mm/year)

iv. Daily non-potable water demand

A4 Large water consuming installations such

as swimming pools and spa hot tubs where the

water is replaced over a greater time interval

do not need to be included as part of the water

calculations.

Calculation tables

A5 Figures from manufacturers’ product

details should be entered into Table A1 to

calculate the consumption of each ﬁtting in litres

per person per day. Where there are multiple

ﬁttings of the same type that have various ﬂow

rates or capacities (e.g. hot and cold taps with

different ﬂow rates), Tables A2.1 to A2.7 should

be used to determine the average ﬂow rate or

capacity of such ﬁttings. The consumption of

water softeners in litres per person per day is

calculated using Table A3. All values throughout

the water efﬁciency calculator should be rounded

to two decimal places with the exception of the

total water consumption ﬁgures, which should be

rounded to one decimal place.

A6 The total calculated use, resulting from

Table A1, is the total consumption of all water

consuming ﬁttings per person. To calculate

the litres of water consumed per person per

day, any savings from grey or rainwater need

to be deducted from the total calculated use

using ﬁgures from Tables A4.6 and A5.5. The

litres/person/day ﬁgure is then multiplied by a

normalisation factor to determine the total water

consumption per person.

A7 To calculate the total water consumption,

an additional allowance for external water use is

added on to the total water consumption. This

ﬁgure is set at 5 litres/person/day.

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G APPENDIX A – WATER EFFICIENCY CALCULATOR FOR NEW DWELLINGS

Table A1: The water efﬁciency calculator

(1) (2) (3) (4)

Installation type Unit of

measure

Capacity/

ﬂow rate

Use

factor

Fixed use

(litres/

person/

day)

Litres/

person/day

= [(1) ⴛ (2)] + (3)

WC (single ﬂush) Flush volume (litres) 4.42 0.00

WC (dual ﬂush) Full ﬂush volume (litres) 1.46 0.00

Part ﬂush volume (litres) 2.96 0.00

WCs (multiple ﬁttings) Average effective

ﬂushing volume (litres)

4.42 0.00

Taps (excluding kitchen/utility room taps) Flow rate (litres/minute) 1.58 1.58

Bath (where shower also present) Capacity to overﬂow

(litres)

0.11 0.00

Shower (where bath also present) Flow rate (litres/minute) 4.37 0.00

Bath only

Capacity to overﬂow

(litres)

0.50 0.00

Shower only

Flow rate (litres/minute) 5.60 0.00

Kitchen/utility room sink taps

Flow rate (litres/minute) 0.44 10.36

Washing machine

Litres/kg dry load 2.1 0.00

Dishwasher

Litres/place setting 3.6 0.00

Waste disposal unit

Litres/use If present = 1

If absent = 0

3.08 0.00

Water softener

Litres/person/day 1.00 0.00

(5)

Total calculated use = (Sum column 4)

(6)

Contribution from greywater

(litres/person/day) from Table 4.6

(7)

Contribution from rainwater

(litres/person/day) from Table 5.5

(8)

Normalisation factor 0.91

(9)

Total water consumption

= [ (5) – (6) – (7) ] = (8)

(10)

External water use 5.0

(11) Total water consumption

= (9) + (10) (litres/person/day)

Consumption from multiple ﬁttings

A8 Where terminal ﬁttings with varying ﬂow

rates and capacities are speciﬁed (e.g. hot and

cold taps with different ﬂow rates, two types of

shower etc.), the average consumption should be

calculated as set out in Tables A2.1 to A2.7:

a) Enter the full ﬂow rate or volume of each type

of ﬁtting into column (a) of the relevant table.

b) For taps, where there are separate hot and

cold water taps, the ﬂow rate of each tap

should be entered separately as two tap

types to calculate the average ﬂow rate.

c) Calculate the total consumption per ﬁtting

type.

d) Calculate the average ﬂow rate/volume of the

ﬁttings detailed.

e) Enter the ﬂow rate/volume of the ﬁtting with

the highest ﬂow rate/volume into box (f) with

the exception of WCs, where this step is not

relevant.

f) Calculate the proportionate ﬂow rate/volume

by multiplying the highest ﬂow rate/volume

by a factor of 0.7 with the exception of WCs,

where this step is not relevant.

A9 Where the average ﬂow rate/volume is

lower than the proportionate ﬂow rate/volume,

the proportionate ﬁgure must be entered into

Table A1. The proportionate ﬁgure limits the ﬂow

rate/volume that can be speciﬁed to a proportion

equal to 70 per cent of the highest ﬂow rate/

volume. This reduces the beneﬁt of specifying

ultra low ﬁttings to bring the average ﬂow rate/

volume down, where such ultra low ﬁttings may

not be acceptable to dwellings occupants.

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APPENDIX A – WATER EFFICIENCY CALCULATOR FOR NEW DWELLINGS G

A10 The ﬁgure which is the greater of the

average or proportionate ﬂow rate/volume should

be used. This is so that, where the average ﬂow

rate/volume is signiﬁcantly lower than the highest

ﬂow rate/volume speciﬁed, the calculation sets a

limitation for what ﬁgure can be assumed.

Table A2.1: Consumption calculator

for multiple taps (excluding kitchen

sink taps)

(a) (b) (c)

Tap ﬁtting

type

Flow rate

(litres/min)

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d) Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average ﬂow rate (litres/min) = [(e)/(d)]

(f) Maximum ﬂow rate

(litres/min)

Proportionate ﬂow rate

(litres/min) = [(f) = 0.7]

Table A2.2: Consumption calculator

for multiple baths

(a) (b) (c)

Bath ﬁtting

type

Capacity

to overﬂow

(litres)

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d) Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average capacity to overﬂow = [(e)/(d)]

(f) Highest capacity to

overﬂow (litres)

Proportionate capacity to

overﬂow (litres) = [(f) = 0.7]

Table A2.3: Consumption calculator

for multiple taps (kitchen/utility

room sink)

(a) (b) (c)

Tap ﬁtting

type

Flow rate

(litres/min)

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d) Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average ﬂow rate (litres/min) = [(e)/(d)]

(f) Highest ﬂow rate

(litres/min) (litres)

Proportionate ﬂow rate

(litres/min) = [(f) = 0.7]

Table A2.4: Consumption calculator

for multiple dishwashers

(a) (b) (c)

Type of

dishwasher

Litres per

place

setting

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d) Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average litres per place setting = [(e)/(d)]

(f) Highest litres per place

setting

Proportionate litres per place setting = [(f) = 0.7]

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Table A2.5: Consumption calculator

for multiple washing machines

(a) (b) (c)

Type of

washing

machine

Litres per

kg dry load

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d)

Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average litres per kilogram of dry load = [(e)/(d)]

(f) Highest litres per kilogram of dry load

Proportionate litres per kilogram of

dry load = [(f) = 0.7]

Table A2.6: Consumption calculator

for multiple showers

(a) (b) (c)

Shower

ﬁtting type

Flow rate

(litres/min)

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d)

Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average ﬂow rate (litres/min) = [(e)/(d)]

(f) Highest ﬂow rate

(litres/min)

Proportionate ﬂow rate

(litres/min) = [(f) = 0.7]

A11 Where more than one type of WC is

provided, the average effective ﬂushing volume is

calculated using Table A2.7 below. The average

effective ﬂush volume should then be entered

into Table A1 in the row ‘WCs (multiple ﬁttings)’.

Table A2.7: Consumption calculator

for multiple WCs

(a) (b) (c)

WC type Effective

ﬂushing

volume*

(litres)

Quantity

(No.)

Total per

ﬁtting type

= [(a) ⴛ (b)]

(d)

Total

(Sum of all quantities)

(e) Total

(Sum of all totals per

ﬁtting type)

Average effective ﬂushing volume

(litres) = [(e)/(d)]

* The effective ﬂushing volume for dual ﬂush WCs is:

(full ﬂushing volume (litres) = 0.33) + (part ﬂushing volume

(litres) = 0.67)

Ion exchange water softener

A12

Ion exchange water softeners use

water in order to clean the resin that is used

to absorb the mineral content of the dwelling’s

water supply. This cleaning process is referred

to as the regeneration cycle, which occurs on

a frequency dependent on the type of water

softener speciﬁed and the hardness of the

water. The water efﬁciency calculator looks at

the water consumed per regeneration cycle that

is beyond a level of good practice. The good

practice level has been determined at a level of

water consumption as a percentage of the water

softener’s total capacity which is set at 4 per cent.

A13 The ﬁgure entered into the calculator

is the volume of water consumed beyond this

level of good practice to promote the use of

more efﬁcient water softeners. Where the water

softener achieves a percentage that is equal

to, or lower than this good practice benchmark

ﬁgure, zero can be entered into Table A1 of the

calculator for water softeners. The following

formula is used to determine the litres of water

consumed per person per day that is beyond the

good practice level of 4 per cent.

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A14 Litres of water consumed per person per

day beyond the 4 per cent good practice level:

= [1 – (4 / (a))] = ((b) = (c))

Where:

(a) = % of total capacity* used per

regeneration

(b) = Litres of water consumed per

regeneration

per day

*the total capacity is the volume of water

that ﬂows through the water softener

between regeneration cycles. This volume

dependent on the hardness of the water

and the total capacity used in this calculation

needs to reﬂect the hardness of water

speciﬁc to the geographic location of the

speciﬁc development. This ﬁgure should be

determined from manufacturer’s product

details.

A15 To calculate the litres of water consumed

per person per day beyond the 4 per cent good

practice level, enter details of the water softener

into Table A3. Where the result indicates zero or a

negative ﬁgure, zero should be entered into Table

A1 for water softeners. The number of occupants

entered into the table should be based on two

in the ﬁrst bedroom and one in each additional

room. Studio ﬂats should assume for two

occupants.

Table A3: Water softener consumption

calculation

(a) Total capacity used per regeneration (%)

(b)

Water consumed per regeneration (litres)

(c)

Average number of regeneration cycles per day (No.)

(d) Number of occupants served by the system (No.)

(e) Water consumed beyond 4% (litres/day)

= [1 - [4/(a)]] = [(b) = (c)]

(f) Water consumed beyond 4% (litres/person/day)

= [(e)/(d)]

Greywater calculations

Greywater demand calculation

A16 Where all WCs and/or washing machines

are being supplied with greywater, the

consumption values should be copied from

Column 4 of Table A1 and entered into Table A4.6

to calculate the greywater savings.

A17 Where greywater is only being supplied to

a proportion of ﬁttings such as just to one WC or

washing machine, the proportion is calculated by

ente

ring details into Tables A4.1 and A4.2.

Table A4.1: Greywater demand

calculations – WCs

(a) (b) (c) (d)

Effective

ﬂushing

volume

(litres)

Number

of ﬁttings

present

Quantity

using

greywater

Greywater

demand

= [(a) ⴛ (c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

greywater

demand

= Sum of (d)

Average greywater demand

from WCs

= (f)/(e) = 4.42

Table A4.2: Greywater demand

calculations – washing machines

(a) (b) (c) (d)

Litres per kg Number

of ﬁttings

present

Quantity

using

greywater

Greywater

demand

= [(a) ⴛ (c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

greywater

demand

= Sum of (d)

Average greywater demand

from washing machines

= [(f)/(e)] = 2.1

Greywater collection calculations

A18 Where greywater is to be collected from all

ﬁttings including the shower, bath and wash hand

basin taps, the total water consumption of the

ﬁttings calculated in Table A1 represents the total

greywater collected, the sum of the consumption

ﬁgures for ﬁttings from which greywater is

collected (from column 4 of Table A1) should

be entered into Table A4.6. Where greywater is

only being collected from a proportion of ﬁttings,

such as just some of the taps, the calculations in

Tables A4.3 to A4.5 should be followed and the

results entered into Table A4.6.

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G APPENDIX A – WATER EFFICIENCY CALCULATOR FOR NEW DWELLINGS

Table A4.3: Greywater collection

calculations – taps

(a) (b) (c) (d)

Litres per

minute

Number

ﬁttings

present

Quantity

supplying

greywater

Greywater

supply

= [(a) ⴛ

(c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

greywater

supply

= Sum of (d)

Average greywater

supply from taps

= [(f)/(e)] = 1.58 + 1.58

Table A4.4: Greywater collection

calculations – showers

(a) (b) (c) (d)

Litres per

minute

Number

of ﬁttings

present

Quantity

supplying

greywater

Greywater

supply

= [(a) ⴛ (c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

greywater

supply

= Sum of (d)

Average greywater supply

from showers (where bath

present)

= [(f)/(e)] = 4.37

Average greywater supply

from showers (shower only)

= [(f)/(e)] = 5.60

Table A4.5: Greywater collection

calculations – baths

(a) (b) (c) (d)

Litres per

minute

Number

of ﬁttings

present

Quantity

supplying

greywater

Greywater

supply

= [(a) ⴛ (c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

greywater

supply

= Sum of (d)

Average greywater supply

from baths (where shower

present)

= [(f)/(e)] = 0.11

Average greywater supply

from baths (bath only)

= [(f)/(e)] = 0.50

Greywater savings calculations

A19 Where greywater is to be reused within

the dwelling, the savings from greywater can be

calculated by entering the following details into

Table A4.6:

a) Calculate the water to be recycled from Table

A1 and/or using the method set out in section

A18 where just a proportion of ﬁttings are

being collected from.

b) Determine the percentage of greywater

collected to be recycled based upon

manufacturer or system designer details of

the system speciﬁed.

c) Determine the water demand of the ﬁttings to

be provided with greywater which can include

WCs and washing machines depending

on the quality of the treated water. This

is determined from the WC and washing

machine consumption from Table A1 or

Tables A4.1 and A4.2 in paragraphs A16

and A17.

d) Multiply the volume of water to be recycled

with the percentage of recycled water

(determined in b. above) which will determine

the actual volume of greywater available.

Where the greywater supply is greater than

the demand, the greywater savings are equal

to the demand. Where the demand is greater

than the greywater supply, the savings are

equal to the supply.

e) Enter the greywater saving ﬁgure from Table

A4.6 into Table A1.

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APPENDIX A – WATER EFFICIENCY CALCULATOR FOR NEW DWELLINGS G

Table A4.6: Greywater collection calculation

(a) (b) (c) (d) (e)

Bath, shower and

wash hand basin

usage (litres/person/

day)

Percentage of used

water (a) to be

recycled

(%)

Greywater available for

use (litres/person/day)

= (a) ⴛ [(b)/100]

Greywater demand

(litres/person/day)

(from Table A1 or

A4.2 and A4.3)

Greywater savings

(litres/person/day)

Where (c) is greater

than (d), (e) = (d),

otherwise

(e) = (c)

A20 Where a communal greywater system is

to be provided supplying more than one home,

Tables A4.1 to A4.5 can be used in the same

way. The ﬁgures

entered into Table A4.6 need to

be entered on an individual dwelling basis and

not using ﬁgures to reﬂect the communal system

as a whole. The percentage collected ﬁgure will,

however, need to be based on manufacturer or

system designer details of the communal system

speciﬁed.

Rainwater calculations

Rainwater collection calculations

A21

Where rainwater is to be used, the

following calculation method should be followed

by entering the relevant details into Table A5.1 or

Table A5.2 to calculate the rainwater collection

volume.

A22 For Table A5.1 using the intermediate

approach from BS 8515:

a) Calculate the volume of water collected using

the collection area, yield coefﬁcient and

hydraulic ﬁlter efﬁciency and average rainfall

with guidance from BS 8515.

b) Calculate the daily rainwater collection in box

(d) using the collection area, yield coefﬁcient,

hydraulic ﬁlter efﬁciency and rainfall.

c) Enter the number of occupants into box (e),

which can be based on two occupants in

the ﬁrst bedroom and one occupant in each

additional bedroom. A studio ﬂat should

assume

two occupants.

d) Where a communal rainwater system is to

be provided supplying more than one home,

Table A5.1 can be used in the same way

calculating the total volume collected for the

communal system and dividing it by the total

number of occupants served by the system.

This ﬁgure should then be entered in

Table A5.5.

Table A5.1: Rainwater collection

calculation – BS 8515 intermediate

approach

(a) Collection area (m

)

(b) Yield coefﬁcient and hydraulic ﬁlter

efﬁciency e.g. 0.7

(d) Daily rainwater collection

(litres) = [(a) = (b) = (c)]/365

(e) Number of occupants

(f) Daily rainwater per person (litres) = [(d)/(e)]

A23 For Table A5.2 using the detailed

approach as described in BS 8515, enter details

of the total daily rainwater collection (litres) and

the number of occupants to calculate the daily

rainwater per person (litres) and enter into

Table A5.5.

Table A5.2: Rainwater collection

calculation – BS 8515 detailed

approach

(a) Daily rainwater collection (litres)

(b) Number of occupants

A24 The calculation detailed above in Table

A5.2 is sufﬁcient for evaluating the principles

of the proposed system in the proposed

development. However, for sizing of storage

capacity and all other design and installation

details, BS 8515 should be followed.

Rainwater demand calculations

A25 Where all WCs and/or washing

machines are being supplied with rainwater, the

consumption should be taken from Table A1 and

entered into Table A5.5 to calculate the rainwater

savings.

A26 Where rainwater is only being supplied to

a proportion of ﬁttings, such as just to one WC

or washing machine, the proportion is calculated

using Table A5.3 and A5.4. This rainwater

demand can then be entered into Table A5.5 to

calculate the rainwater savings.

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G APPENDIX A – WATER EFFICIENCY CALCULATOR FOR NEW DWELLINGS

Table A5.3: Rainwater demand

calculations – WCs

(a) (b) (c) (d)

Effective

ﬂushing

volume (litres)

Number

of ﬁttings

present

Quantity

using

rainwater

Rainwater

demand

= [(a) ⴛ (c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

rainwater

demand

= Sum of (d)

Average rainwater demand = [(f)/(e)] = 4.42

from WCs

Table A5.4: Rainwater demand

calculations – washing machines

(a) (b) (c) (d)

Litres per kg Number

of ﬁttings

present

Quantity

using

rainwater

Rainwater

demand

= [(a) ⴛ (c)]

(e) Total

ﬁttings

= Sum of (b)

(f) Total

rainwater

demand

= Sum of (d)

Average rainwater demand

from washing machines

= [(f)/(e)] = 2.1

Rainwater saving calculations

A27 Enter the total volume of rainwater

collected per person per day from Table A5.1 or

Table A5.2 depending on the BS 8515 approach

followed. Enter the total consumption of ﬁttings

using rainwater (demand) from column 4 of Table

A1, where rainwater is to be used in all WCs and/

or washing machines. Where rainwater is only

being used in a proportion of ﬁttings, enter the

total demand of WCs and washing machines

from Table A5.3 and Table A5.4. This ﬁgure

should then be entered into Table A1 to calculate

the internal water consumption.

Table A5.5: Rainwater saving

calculations for new dwellings

Litres per person per day

(a) Rainwater collected

(b) Rainwater demand

= [(a)/(b)] or (b)

*where the amount collected (a) is greater than the demand (b),

the rainwater savings (c) are equal to the demand (b)

Fittings approach

A28 The ﬁttings approach given in G2 uses

the methodology described in this appendix to

calculate the water consumption of ranges of

ﬁttings that meet the performance targets.

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Appendix B – Wholesome water

B1 For ease of reference, the provisions on

the wholesomeness of water in legislation made

under section 67 of the Water Industry Act 1991

are set out below. This legislation is subject to

Crown copyright protection, and is available in its

original form on www.legislation.gov.uk.

B2 For convenience, the relevant regulations

and amendments concerned are reproduced

here in a consolidated form with some deletions

or additional text where it is considered it would

assist comprehension. These are only extracts

of the legislation, and in any case of doubt the

original regulations and amendments should

be consulted.

B3 For reasons of brevity the Schedules and

Tables of these Regulations are not reproduced

here.

Water Supply (Water Quality)

Regulations 2000 (SI 2000/3184)

Note: The Water Supply (Water Quality)

Regulations 2001 (SI 2001/3911) which apply in

Wales contain equivalent requirements.

Wholesomeness

4. (1) Water supplied:

a. for such domestic purposes as consist

in or include, cooking, drinking, food

preparation or washing; or

b. to premises in which food is produced,

shall, subject to paragraphs (4) and

(5), be regarded as wholesome for the

purposes of Chapter III [(quality and

sufﬁciency of supplies) of Part III (water

supply) of the Water Industry Act 1991],

as it applies to the supply of water for those

domestic purposes, if the requirements

of paragraph (2) are satisﬁed.

(2) The requirements of this paragraph are:

a. that the water does not contain:

i. any micro-organism (other than

a parameter listed in Schedule I)

or parasite; or

ii. any substance (other than a

parameter listed in Schedule I),

at a concentration or value which

would constitute a potential danger

to human health;

b. that the water does not contain

any substance (whether or not a

parameter) at a concentration or value

which, in conjunction with any other

substance it contains (whether or

not a parameter) would constitute a

potential danger to human health;

c. that the water does not contain

concentrations or values of the

parameters listed in Tables A and

B in Schedule 1 in excess of or,

as the case may be, less than, the

prescribed concentrations or values;

d. that the water satisﬁes the formula

[nitrate]/50 + [nitrite]/3 ⱕ1, where

the square brackets signify the

concentrations in mg/l for nitrate

(NO

) and nitrite (NO

(3) The point at which the requirements of

paragraph (2), in so far as they relate to

the parameters set out in Part I of Table

A and in Table B in Schedule 1 are to be

complied with, is:

a. in the case of water supplied from a

tanker, the point at which the water

emerges from the tanker;

b. in any other case, the consumer’s tap.

(4) Water supplied for regulation 4(1)

purposes shall not be regarded as

wholesome for the purposes of Chapter

III if, on transfer from a treatment works

for supply for those purposes:

a. it contains a concentration of the

coliform bacteria or E. coli parameter

(items 1 and 2 in Part II of Table

A in Schedule 1) in excess of the

prescribed concentrations; or

b. it contains a concentration of nitrite

in excess of 0.1mgNO

/l.

(5) Subject to paragraph (6), water supplied

for regulation 4(1) purposes shall not be

regarded as wholesome for the purposes

of Chapter III if, on transfer from a service

reservoir for supply for those purposes, it

contains a concentration of the coliform

bacteria or E. coli parameter in excess of

the prescribed concentrations.

(6) Water transferred from a service reservoir

for supply for regulation 4(1) purposes

shall not be regarded as unwholesome for

the purposes of Chapter III because the

maximum concentration for the coliform

bacteria parameter is exceeded if, as

regards the samples taken in any year in

which the reservoir in question is in use,

the results of analysis for that parameter

establish that in at least 95 per cent of

those samples coliforms were absent.

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Sanitation, hot water safety and water efﬁciency Approved Document G

G APPENDIX B – WHOLESOME WATER

Private Water Supplies Regulations

2009 (SI 2009/3101)

Note: The Private Water Supplies (Wales)

Regulations (SI 2010/66) which apply in Wales

contain equivalent requirements.

Wholesomeness

4. Water is wholesome if all the following

conditions are met:

a. it does not contain any micro-organism,

parasite or substance, alone or in

conjunction with any other substance,

at a concentration or value that would

constitute a potential danger to human

health;

b. it complies with the concentrations or values

speciﬁed in Part 1 of Schedule 1; and

c. in the water:

nitrate (mg/l)

ⱕ1

50 3

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ATER

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Sanitation, hot water safety and water efﬁciency

Appendix C – References

Relevant legislation

(available via www.opsi.gov.uk)

The Building (Approved Inspectors etc.)

Regulations 2010 (SI 2010/2215).

The Building Regulations 2010 (SI 2010/2214).

The Food Hygiene (England) Regulations 2006

(SI 2006/14). HMSO, 2006.

The Food Hygiene (Wales) Regulations 2006

(SI 2006/31 W5). HMSO, 2006.

The Gas Safety (Installation and Use)

Regulations 1994 (SI 1994/1886). HMSO, 1994.

The Private Water Supplies Regulations 2009

(SI 2009/3101). HMSO, 2009.

The Private Water Supplies (Wales) Regulations

2010 (SI 2010/66). HMSO, 2010.

The Water Supply (Water Fittings) Regulations

1999 (SI 1999/1148). HMSO, 1999.

The Water Supply (Water Quality) Regulations

2000 (SI 2000/3184). HMSO, 2000.

The Workplace (Health, Safety and Welfare)

Regulations 1992 (SI 1992/3004). HMSO, 1992.

The Water Industry Act 1991 HMSO, 1991.

The Health and Safety at Work etc. Act 1974

HMSO, 1974.

The European Communities Act 1972 HMSO, 1972.

Standards

ANSI-NSF 41:2005 + A1:2007. Non-liquid

saturated treatment system. NSF, 2007.

BS EN 257:1992 Mechanical thermostats for

gas-burning appliances. BSI, 1992.

BS 417-2:1987 Speciﬁcation for galvanized low

carbon steel cisterns, cistern lids, tanks and

cylinders. Metric units. BSI, 1987.

BS 853-1:1996 Speciﬁcation for vessels for use

in heating systems. Caloriﬁers and storage

vessels for central heating and hot water supply.

BSI, 1996.

BS EN ISO 1043-1:2002 Plastics. Symbols and

abbreviated terms. Basic polymers and their

special characteristics.

BS EN 1111:1999 Sanitary tapware. Thermostatic

mixing valves (PN 10). General technical

speciﬁcation. BSI, 1999.

BS EN 1287:1999 Sanitary tapware. Low

pressure thermostatic mixing valves. General

technical speciﬁcations. BSI, 1999.

BS EN 1490:2000 Building valves. Combined

temperature and pressure relief valves. Tests and

requirements. BSI, 2000.

BS 1566-1:2002 Copper indirect cylinders

for domestic purposes. Open vented copper

cylinders. Requirements and test methods.

BSI, 2002.

BS 3198:1981 Speciﬁcation for copper hot water

storage combination units for domestic purposes.

BSI, 1981.

BS 4213:2004 Cisterns for domestic use. Cold

water storage and combined feed and expansion

(thermoplastic) cisterns up to 500 l. Speciﬁcation.

BSI, 2004.

BS 5918:1989 Code of Practice for Solar heating

systems for domestic hot water. BSI 1989.

BS 6283-2:1991 Safety and control devices

for use in hot water systems. Speciﬁcations for

temperature relief valves for pressures from 1 bar

to 10 bar. BSI, 1991.

BS 6283-3:1991 Safety and control devices

for use in hot water systems. Speciﬁcation for

combined temperature and pressure relief valves

for pressures from 1 bar to 10 bar. BSI, 1991.

BS 6465-1:2006 + A1:2009 Sanitary installations.

Code of practice for the design of sanitary

facilities and scales of provision of sanitary

and associated appliances. BSI, 2006.

BS 6465-2:1996 Sanitary installations.

Code of practice for space requirements

for sanitary appliances. BSI, 1996.

BS 6465-3:2006 Sanitary installations.

Code of practice for the selection, installation

and maintenance of sanitary and associated

appliances. BSI, 2006.

BS 6700:2006 + A1:2009 Design, installation,

testing and maintenance of services supplying

water for domestic use within buildings and their

curtilages. Speciﬁcation. BSI, 2006.

BS 7291-1:2006 Thermoplastics pipes and

associated ﬁttings for hot and cold water for

domestic purposes and heating installations in

buildings. General requirements.

BS 7291-2:2006 Thermoplastics pipes and

associated ﬁttings for hot and cold water for

domestic purposes and heating installations in

buildings. Speciﬁcation for polybutylene (PB)

pipes and associated ﬁttings.

BS 7291-3:2006 Thermoplastics pipes and

associated ﬁttings for hot and cold water for

domestic purposes and heating installations

in buildings. Speciﬁcation for cross-linked

polyethylene (PE-X) pipes and associated ﬁttings.

BS 7671:2008 Requirements for electrical

installations (IET Wiring Regulations 17th Edition).

BS 8000-15:1990 Workmanship on Building Sites

Code of practice for hot and cold water services

(domestic scale). BSI, 1990.

BS 8515:2009 Rainwater harvesting systems,

Code of Practice.

NLINE VER

Sanitation, hot water safety and water efﬁciency Approved Document G

G APPENDIX C – REFERENCES

BS 8525-1:2010, Greywater system – Code of

Practice

BS EN 200:2008, (Sanitary tapware. Single taps

and combination taps for water supply systems

of type 1 and type 2. General technical

specifications.)

BS EN 1112:2008, (Sanitary tapware. Shower

outlets for sanitory tapware for water supply

systems type 1 and type 2. General technical

specification.)

BS EN 12050-1:2001 Wastewater lifting plants for

buildings and sites. Principles of construction and

testing. Lifting plants for wastewater containing

faecal matter.

BS EN 12050-2:2001 Wastewater lifting plants for

buildings and sites. Principles of construction and

testing. Lifting plants for faecal-free wastewater.

BSI, 2001.

BS EN 12050-3:2001 Wastewater lifting plants for

buildings and sites. Principles of construction and

testing. Lifting plants for wastewater containing

faecal matter for limited applications.

BS EN 12897:2006 Water supply. Speciﬁcation

for indirectly heated unvented (closed) storage

water heaters. BSI, 2006.

BS EN 12976-1:2006 Thermal solar systems and

components. Factory made systems. General

requirements. BSI, 2006.

prCEN/TS 12977-1:2008 Thermal solar systems

and components. Custom built systems. General

requirements. BSI, 2001.

BS EN 15092:2008 Building valves. Inline

hot water supply tempering valves. Tests and

requirements. BSI, 2008.

BS EN 60335-2-21:2003 Household and

similar electrical appliances. Safety. Particular

requirements for storage water heaters. BSI, 2003.

BS EN 60335-2-35:2002 Speciﬁcation for safety

of household and similar electrical appliances.

BSI, 2002.

BS EN 60335-2-73:2003 Speciﬁcation for safety

of household and similar electrical appliances.

Particular requirements for ﬁxed immersion

heaters. BSI, 2003.

BS EN 60730-2-9:2002 Automatic electrical

controls for household and similar use. Particular

requirements for temperature sensing controls.

BSI, 2002.