Bathroom zones are specific areas of set dimensions in a bathroom, shower room or wet room. Bathroom zones are not restricted to just bathrooms, the zones also apply to any room which contains a bath or shower, for example a shower in a bedroom.
The zones do not however apply to emergency facilities such as emergency showers used in industrial areas or labs.
The zones determine what electrical equipment can be installed and the minimum specification of that electrical equipment within a specific zone.
BS 7671 Bathroom Zones
Bathroom zones consist of Zone 0, Zone 1 and Zone 2, there is no longer a bathroom Zone 3.
Bathroom Zone 0
Zone 0 is inside of the bath tub, shower tray or shower basin and is the most restrictive bathroom zone.
Bathroom Zone 1
Zone 1 includes the space under the bath tub or shower basin/tray if it is accessible without the use of a tool, otherwise it is not classed as a zone.
If the space under the shower tray, basin or bath tub is open then that is classed as zone 1 – for example some roll top baths.
Vertically zone 1 extends from floor level up to 2250mm (2.25m) or if the fixed shower head or water outlet is higher than 2250mm then zone 1 will extend to the highest point of the fixed shower head or water outlet – for example if the shower head is mounted at 2700mm then zone 1 will extend to at least 2700mm vertically.
For wet rooms or a shower without a shower tray or basin, zone 1 extends horizontally from the centre point of the fixed water outlet to 1200mm.
Bathroom Zone 2
Zone 2 extends horizontally from the edge of the bath tub or shower tray to a distance of 600mm and vertically from the floor level to 2250mm (2.25m) or the highest fixed shower head or water outlet, whichever is the highest – for example if the fixed shower head is mounted at 2700mm from the floor level then zone 2 will extend to at least 2700mm (2.7m) vertically.
Bathroom Zone 3
Zone 3 of a bathroom has been removed from the wiring regulations therefore bathroom zone 3 is no longer applicable to BS 7671.
Open Shower Zones
For zones for a shower without an enclosure see Wet Room Zones below.
Wet Room Zones
Zones within a wet room or a shower without a shower tray, basin or enclosure differ to the standard bathroom zones.
Wet Room Zone 0
Zone 0 for showers without a shower tray, basin or enclosure extends vertically from the floor level to 100mm and extends horizontally the same as zone 1, (See fig. 701.2(f) of BS 7671).
Wet Room Zone 1
Wet room zone 1 for rooms containing a shower without a shower tray, basin and or an enclosure, zone 1 extends horizontally from the centre of the fixed shower head or water outlet to 1.2m and vertically extending from floor level up to 2.25m or to the top of the fixed water outlet, whichever is highest.
Wet Room Zone 2
For wet rooms or showers without a basin or shower tray there is no zone 2, instead zone 1 is extended to 1200mm (1.2m) horizontally, (see regulation 701.32.3(ii)(b)).
For a more detailed guide and for further information on the wiring regulations applicable to bathrooms see Section 701 Locations Containing a Bath or Shower of BS 7671 which covers the requirements of electrical installations in locations containing a fixed bath (bath tub or birthing pool) or shower and the corresponding zones.
Scroll down below to Related Content for related posts regarding bathroom electrics such as IP Ratings or sockets and spurs in bathrooms