Part P Bathroom Zone Regulations

Question 1

How many zones are defined in a bathroom containing a fixed bath under BS 7671?

Accepted Answer

Three: Zone 0, Zone 1 and Zone 2 (plus an area outside the zones)

Answer

BS 7671 Section 701 defines Zone 0 (inside the bath/shower tray), Zone 1 (above the bath/tray up to 2.25 m), and Zone 2 (outside Zone 1 extending 0.6 m horizontally), plus an area outside all zones.

Question 2

What is Zone 0 in a bathroom?

Accepted Answer

The interior of the bath or shower tray itself — the area always in contact with water

Answer

Zone 0 is the interior of the bath, shower tray or shower basin — the zone that is always filled with or in direct contact with water, requiring the highest level of ingress protection (IPX7 or IPX8).

Question 3

What minimum IP rating is required for electrical equipment in Zone 0?

Accepted Answer

IPX7 (protection against temporary immersion)

Answer

Equipment installed in Zone 0 must have a minimum rating of IPX7 (capable of withstanding temporary immersion), as it is in direct contact with water; only SELV at 12 V AC or 30 V DC max is permitted in this zone.

Question 4

What is Zone 1 in a bathroom with a fixed bath?

Accepted Answer

The area above the bath tub to a height of 2.25 m above the floor, extending over the full width and length of the bath

Answer

Zone 1 extends vertically from the bottom of the bath (or shower tray) up to 2.25 m above the finished floor level, over the horizontal extent of the bath or shower area.

Question 5

What electrical equipment is permitted in Zone 1 of a bathroom?

Accepted Answer

Only equipment with a minimum IPX4 rating, supplied at SELV, or shower units and bath heaters rated for Zone 1 use

Answer

In Zone 1, only equipment specifically designed for the zone (rated IPX4 minimum) is permitted — SELV shaving sockets, shower units, bath heaters and whirlpool units designed for Zone 1 installation are allowed.

Part P Electrical Practice Test

Part P Electrical Practice Test

Part P Bathroom Zone Regulations