Locations containing
a bath or shower
BS 7671: 2008
Section 701
This leaflet summarises the new requirements
of BS7671: 2008 IEE Wiring Regulations
(17th Edition) that relates to locations
containing a bath or shower. This guidance
note refers to situations in dwellings, whereas
the actual regulations relate to a bath or
shower location in any type of building.
BS7671: 2008 was published in January 2008, and
all electrical installations being designed after July
1st 2008 must comply with the requirements of the
new edition.
For further detailed reading, Chapter 701 of BS7671
outlines all the requirements, with additional practical
guidance also being given in the IEE’s ‘On-Site Guide’.
Locations containing a bath or shower
Section 701
1. Scope (regulation 701.1)
The scope now covers any location containing a fixed bath
(‘bath tub’) or shower. It should be noted that this could also
apply to, for example, a bedroom which has a shower or bath
It should also be noted that zones generally end at ceilings, walls,
floors, doors and partitions.
Although the illustrations at the end of this leaflet generally
give all the permutations of the commonly encountered zone
facility within.
boundaries, the following fundamental conditions now apply:
As well as applying to such facilities in dwellings, the scope
Zone 0 (regulation 701.32.2)
also applies to all types of buildings – for example communal
showers in commercial buildings as well such facilities in industrial
buildings.
It should be noted that the requirements do not apply to wash
facilities that may be provided as ‘emergency facilities’, but a note
is made that for bath or shower facilities for medical treatments,
special additional requirements may also apply.
This is still the interior of the bath or shower basin, and for
practical measuring purposes, the top of the zone would still be
taken as to the point at where water would overspill if the basin
were allowed to overflow.
For showers with no basin, such as a ‘wet room’, the Zone
0 has an upper limit height of 0.1m from the floor, with its
horizontal extent being the same as that defined for zone 1 –
that being 1.2m from the fixed water outlet (see figures 7 & 8).
2. Classification of zones
As with BS7671: 2001, the new BS7671: 2008 document bases
its requirements on the concept of zones, which can be clearly
and unambiguously defined by simple measurement. The zone
boundaries effectively limit the type of installation possible and
the type of equipment that is allowable within a particular zone.
Pictorial representations of all zones are given in the illustrations
at the back of this leaflet.
Firstly, it should be noted that the upper limit of all zones is now
2.25m, with no ‘hook-over’ of zones above other zones as was
previously the case in the 16th Edition.
2
Zone 1 (regulation 701.32.3)
This is defined as being directly above Zone 0 to a height of up
to 2.25m or up to the highest fixed showerhead or water outlet
if this is above 2.25m.
In the case of a shower basin with no defined ‘edge’ the vertical
edge of the zone is taken to be 1.2m from the centre point of
the fixed water outlet.
Note: Zone 1 does not contain Zone 0, but does include the
space under an open-sided bath. However, if the space under a
bath is accessible only by the use of a tool, it is deemed to be
outside of the zones.
3
Zone 2 (regulation 701.32.4)
This is defined as extending horizontally from the edge of Zone
1 by a further 0.6m and vertically to the limiting 2.25m or height
of the highest water outlet.
For showers without a defined basin, there is no Zone 2, due to
the extended Zone 1
Zone 3
This no longer exists and its definition has been removed from
It is considered due to the very specialist nature of implementing
electrical separation that it will be rarely used in dwelling
applications.
Extra low voltage – SELV and PELV
(regulation 701.414.4.5)
This regulation permits the use of these systems in zones 0,
1 and 2, but makes the requirement that even if used, basic
insulation must still be employed and barriers and enclosures
must be provided, meeting at least IPXXB or IP2X.
the regulations.
3.Protection for safety: protection
against shock (regulation 701.41)
Additional Protection – supplementary equipotential
bonding (regulation 701.415.2)
This regulation governs the application of supplementary
bonding and is often a requirement that has been misread and
Prohibited methods of shock protection
(regulations 701.410.3.5 & 701.410.3.6)
misunderstood.
The first requirement in this series of regulations is that the
BS7671: 2001 regulations, in that it requires supplementary
protective measures of ‘obstacles’, ‘placing out of reach’, ‘non
bonding between all extraneous conductive parts and circuit
conducting locations’ and ‘earth free local equipotential bonding’
protective conductors supplying equipment within the location,
defined and being permissible elsewhere in BS7671 are not
specifically mentioning metal pipework systems, heating
permitted for use in locations containing a bath or shower.
pipework, air conditioning ductwork and accessible metal
These measures are seldom encountered in dwelling applications
structural parts.
in any case.
Additional protection by RCDs
(regulation 701.411.3.3)
This new regulation now requires that all circuits of the location
shall be provided with additional protection of RCDs which
operate at a residual current of 30mA and trip within 40mS
It basically continues the requirement of the 16th Edition
It must be remembered that metal items fed by plastic pipes,
window frames, door frames, architraves and the like are
normally considered to be ‘isolated’ unless in contact with
metallic structural parts or systems. As such bonding to such
items would normally be unnecessary.
The golden rule to consider here is, do the metallic parts enter
when tested at (x5) their residual current rating.
or leave the room and therefore capable of introducing a
It also requires that suitable splitting and arrangement of circuits
they may be considered to be isolated parts – subject to testing
and protection be such so as to minimise inconvenience if a single
of course.
device were to trip out. Best practice here is of course to use
RCBOs, or, if using the now common dual RCD split boards, to
potential into the room from other parts of the building? If no,
Any such supplementary bonding does not actually have to
arrange circuits carefully across the two or more RCDs.
be within the location itself – it could be in an adjacent airing
Electrical separation (regulation 701.413)
bonds are as near as practical to the point of entry of the
This regulation allows the concept of ‘electrical separation’ to
be only used for circuits supplying one item of current using
equipment, or one single socket outlet. It is not permitted to use
‘electrical separation’ in conjunction with electric floor heating
systems.
cupboard for example. Best practice would be to ensure the
extraneous conductive parts into the room – and of course
accessible, if using screwed or bolted connections!
Where the 17th Edition BS7671: 2008 has changed, is that the
These requirements do not differ significantly from the 16th
regulation permits such bonding as described (and required since
Edition regulations.
2001), to be omitted, provided that four basic conditions
are all met, these being:
• The building has main bonding conductors in place meeting
the regulations
Erection of switchgear, control gear and wiring
accessories (regulation 701.512.3)
This regulation ties in the regulations concerning external
influences, and regulations relating to shock protection, into
• And all final circuits within the location meet the required
disconnection time as stipulated in regulations 411.3.2.2,
411.3.2.3 and 411.3.2.4.
• And all final circuits in the location have 30mA RCD
simple easy to follow requirements:
Zone 0
no switchgear or accessories can be installed
Zone 1only accessories for SELV circuits (maximum 12V
AC RMS or 30V ripple free DC) to be used, with
protection
the safety source outside the zones 0, 1 and 2.
• And, if in the case of extraneous conductive parts entering
or leaving the room, and therefore not ‘isolated metalwork’,
Zone 2generally switchgear and accessories with switches
or sockets must not be installed. However such
it can be proven that such parts are effectively connected to
equipment fed by SELV circuits (with the source
the main bonding conductors
located outside zones 0,1 and 2), and shaver supply
In practice, the provision of main bonding should not be an
issue, since regulation 131.8 requires it to be in place before any
alteration or addition is undertaken in any case.
units complying with BSEN 61558-2-5 may be used.
Note: It is this regulation that now permits ‘standard’ socket
outlets to be used in locations containing a bath or shower,
Similarly, the requirements to provide 30mA RCD protection to
provided that the socket is mounted at least 3m from the
the bathroom circuits can be undertaken in a number of different
boundary of zone 1.
ways, depending on what other work is involved in the building.
It is also worth remembering, that a 30mA RCD achieving the
In practice in the majority of typical bathrooms in dwellings, the
room size will still effectively prohibit the use of socket outlets.
40mS disconnection time at (x5) residual current will invariably
satisfy whatever disconnection time is required by regulations
411.3.2.2, 411.3.2.3 and 411.3.2.4.
Current using equipment (regulation 701.55)
This regulation ties in the regulations concerning external
influences, and regulations relating to shock protection, into
4.Selection and erection of equipment
(regulation 701.5)
Zone 0
External influences (regulation 701.512.2)
Only current using equipment complying with all of the following
This regulation gives clear requirements for ingress protection,
requirements may be used in this zone:
according to installed zones:
• Zone 0
IPX7 minimum
• Zones 1 and 2IPX4 minimum, unless splashing is likely
– then IPX5
A notable requirement is that shaver supply units which comply
• Must comply with the relevant standard, be suitable for
use in this zone, and be installed fully in accordance with
manufacturer’s instructions
• Must be fixed and permanently connected
• Must be SELV at a nominal voltage not exceeding 12V AC
with the new BSEN 61558-2-5 installed in zone 2 where
RMS or 30V ripple free DC, with safety source located
unlikely to be splashed by direct sprays from showers, will not
outside zones 0, 1 and 2.
have to meet the IPX4 or 5 requirement.
4
simple easy to follow requirements:
5
Zone 1
Only the following current using equipment may be used in this
zone, provided manufacturer’s instructions make it clear that
such equipment is suitable for this zone:
• Whirlpool units
• Electric showers
• Shower pumps
• Equipment protected by SELV or PELV at a nominal voltage
not exceeding 25V AC RMS or 60V ripple free DC, with
safety source located outside zones 0, 1 and 2. (Note
– different SELV range to zone 0)
• Ventilation equipment
• Towel rails
• Water heating appliances
• Luminaires
Electric floor heating systems (regulation 701.753)
This regulation ties in the regulations concerning external
influences, and regulations relating to shock protection, into
simple easy to follow requirements relating to typical heating
element wires or sheets, requiring that they;
• Comply with a relevant product standard
• Have a metal sheath, or
• Have a metal enclosure, or
• Be covered in fine metallic mesh
In all of the above cases, the metal sheath, enclosure or mesh
must be connected to the circuit protective conductor of the
supply circuit, unless the protective measure of SELV is also used.
In addition to the specific requirements in chapter 701, chapter
753 outlines generic requirements for electric floor heating
systems, which would of course also apply to such systems
installed in locations containing a bath or shower.
Figure 1 Zone dimensions (plan) Bath tub
Figure 2 Zone dimensions (plan) bath tub (fixed partition)
Zone 2
Window
recess
Zone 1
Zone 1
Zone 2
Zone 2
Zone 0
Zone 0
0.6 m
0.6 m
s
Window recess
(0.6-s) m
Zone 2
s = thickness of partition
Figure 3 Zone dimensions (elevation) bath tub
Ceiling
Outside zones
Window
recess
zone 2
Outside zones
zone 1
zone 2
2.25 m
zone 0
*
0.6 m
Figure 4 Zone dimensions (plan) shower with basin
Zone 0
Zone 1
Zone 2
0.6 m
Figure 5 Zone dimensions (plan) shower basin (fixed partition)
Zone 0
Zone 2
Zone 1
s
(0.6-s) m
s = thickness of partition
6
7
Figure 6 Zone dimensions (elevation) shower with basin
Luminaire
e
R
Recess
above ceiling
Ceiling
Outside zones
zone 1
Outside zones
zone 2
2.25 m
zone 0
*
0.6 m
Figure 7 Zone dimensions (plan) shower without basin (fixed)
Figure 8 Zone dimensions (plan) Shower without basin
Fixed water outlet
Fixed water outlet
y
1.20 m
x
(1.2-y-s) m
s
Zone 1
Zone 0
Zone 1
Zone 0
1.20 m
s = thickness of partition
partition
y = radial distance from the
fixed water outlet to the
inner corner of the partion
NB * See also Figure 9
Figure 9 Zone dimensions (elevation) shower without basin
Ceiling
Outside zones
zone 1
Outside zones
zone 2
2.25 m
0.10 m
zone 0
zone 0
Permanent partition
*Zone 1 if the space
is accessible without
the use of a tool.
Spaces under the
bath accessible only
with the use of a
tool are outside the
zones.
For additional information contact the ELECSA Technical Helpline on 0845 634 9029
EC Certification Limited Mansfield Business Centre, Ashfield Avenue, Mansfield NG18 2AE.
T +44 (0) 845 634 9043
F +44 (0) 845 634 9039
E enquiries@elecsa.co.uk
W www.elecsa.co.uk
The information included in this document is for guidance only. Always refer to definitive source material.