16th Edition (reference only) – NOW superseded by the 17th Edition IEE Regulations.

chapter 5

chapter 6

Special Installations
  --1. - Introduction --2. - Bath tubs and shower basins
  --3. - Swimming pools --4. - Sauna rooms
  --5. - Installations on construction sites --6. - Agricultural & horticultural
--7. - Restrictive conductive locations --8. - Earthing for function & protection
--9. - Caravan, motor homes, caravan parks 10. - Highway power & street furniture
11. - Heating appliances & installations 12. - Discharge lighting
13. - Underground & overhead wiring 14. - Outdoor installations & garden buildings
15. - Installations of machines & transformers 16. - Reduced voltage systems

7.2.2A - Bath and shower room requirements (amended)

The revised Regulations for bath and shower rooms are based on the dimensions of four zones into which the space is divided.

Zone O.
is the interior of the bathtub or the shower basin. In those cases where a shower has no basin, the zone extends 50mm above the floor and includes the volume within the vertical surface at a radius of 1.2m from the water outlet position of a demountable shower head, or at a radius of 0.6m from the position of a fixed shower head.

Zone 1.
extends from Zone 0 up to 2.25m above the floor, and outwards to the extent of the bath or basin, or the extent of Zone 0 as defined above where there is no shower basin. It includes the space below a bath or shower tub or basin where that space is accessible without the use of a tool.

Zone 2.
extends outside Zone 1 for 0.6m horizontally and up to a height of 2.25m. If the ceiling height is more than 2.25m, the space above Zone 1 up to 3m is also zone 2

Zone 3.
extends outside Zone 2 for 2.4m horizontally and up to a height of 2.25m. If the ceiling height is more than 2.25m, the space above Zone 2 up to 3 m is also Zone 3

If the space under a bathtub or shower basin can only be accessed with the use of a tool, that space is outside the zones. If no tool is required the space is Zone 1.

The extent of the zones is shown in Figs 7.1b) to 7.1g) in diagrams which are not to scale.


Figure 7.1b) - Zones for a bathroom (plan).
Note that the same zones apply to a shower room with a shower basin.


Figure 7.1c) - Zones for a bathroom (elevation).
Note that the same zones apply to a shower room with a shower basin.


Figure 7.1d) - Zones for a shower with no basin and a fixed head.


Figure 7.1e) - Zones for a shower room (elevation)
without a basin and having a fixed showerhead.

Where SELV (safety extra-low voltage, see (3.4.4) is used, protection against direct contact must be provided by barriers or enclosures to IP2X (no finger contact) or by insulation which will withstand 500 V a.c for one minute. PELV (which is earthed SELV) is not permitted in bath and shower rooms. Local supplementary equipotential bonding must be installed to connect together the exposed conductive parts of Class 1 and Class 11 equipment in Zones 1,2, and 3 together with extraneous conductive parts, such as metal baths and shower trays, metallic pipes for water, gas, central heating, air conditioning. etc in all zones. Accessible structural metal must also be bonded, although this is unnecessary in the cases of metal door architrave's, window frames and so on, unless these parts are connected to the metal structure of the building (see Fig 7.2, page 127, Electrician's Guide), which in practice is unlikely. These bonding requirements do not apply to Zone 3 where a prefabricated shower or bath is installed in a bedroom.

In some cases, safety extra-low voltage (SELV) at 12V a.c. or 30V ripple-free d.c. is used within bath and shower basin (for example for hoists used by disabled persons). Such systems must be protected against direct contact by the use of barriers or enclosures to IP2X (not accessible by human fingers) or must have insulation that will withstand a test voltage of 500 V a.c. for 1 min. The safety source supplying such a SELV system must be situated outside Zones 0, 1 and 2. Protections by obstacles (3.4.5), placing out of reach (3.4.5), or a non-conducting location (5.8.2) are not allowed in bath or shower rooms.

In every zone, the only wiring permitted is that feeding equipment in that zone, or where it must pass through that zone to reach another unless it is buried deeper than 50mm from the surface. For example, wiring to fixed equipment in Zone 0 may have to pass through Zones 1, 2 and 3 to reach its destination. Zone 2 may be used as a route for wiring needed to feed equipment in Zone 1 below the bath tub or shower or shower basin. In other words, the zones in a shower or bathroom must not be used as routes for through wiring that feeds other services outside the area.

Switch and control gear is permitted in any zone if such gear is incorporated in the equipment installed there, which is suitable for use in that zone. No other switch or control gear is permitted in Zone 0. In Zone 1, only switch and control gear for SELV may be installed, but the safety source for the system must be installed outside Zones 0, 1 and 2. In Zones 2 and 3 or outside the zones but within the bath or shower room, switches and socket outlets are permitted providing that they are fed from an SELV source installed outside Zones 0, 1 and 2. The exception to this is the socket outlet on a shaver supply unit that complies with BS EN 60742, Chapter 2, Section 1, which may be installed in Zones 2 and 3. Insulated operating cords of pull switches are permitted in Zones 1, 2 and 3 but they must comply with BS 3676. All equipment installed in Zone 3 must be protected by an RCD with a rating not exceeding 30 mA.

Electrical equipment installed in a room containing a bath or shower must have protection against the ingress of water as follows:-

in Zone 0, only equipment which is intended for that situation, water protected to IPX7 or

in Zones 1 and 2, IPX4 or
which is protection from splashing. Where water jets may be used for cleaning, such as in public bath and shower facilities, IPX5 or applies, which gives protection against water jets.

in Zone 3, IPX5 or must again be used if cleaning by water jets is likely. See (Table 2.4.), for details of the index of protection (IP) system.

Fixed current-using equipment may be installed in Zone 0 if this is the only reasonable location for it and it is suitable for the conditions in the zone. Water heaters and shower pumps may be installed in Zones 1 and 2, as may other equipments suitable for the conditions, provided that they have the required protection against water and are protected by an RCD with a rating of not more than 30 mA. In Zone 2, luminaires, fans, heating appliances and units for whirlpool baths may also be installed, provided that they comply with the relevant standards. Electric under-floor heating may be installed provided that below any zone a metallic grid or plate connected to the local supplementary equipotential bonding covers it. SELV equipment may be used in any zone provided that its safety source is installed outside Zones 0, 1 and 2.


Fig 7.1g) - Zones for a shower room without a basin and
having a demountable shower head

Remember this Amendment is optional until 1.1.2002 Now return to Section 7.3, page 128 of Published by EPA Press Tel 01799 541207 Fax 01799 541166


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Extracted from The Electricians Guide Fifth Edition
by John Whitfield

Published by EPA Press Click Here to order your Copy.

Click here for list of abbreviations