Part P Bathroom Zone Regulations 1 — Questions and Answers
Question 1: How many zones are defined in a bathroom containing a fixed bath under BS 7671?
- Three: Zone 0, Zone 1 and Zone 2 (plus an area outside the zones) (Correct answer)
- Two: Zone 0 and Zone 1
- Four zones
- One single zone
Correct answer: Three: Zone 0, Zone 1 and Zone 2 (plus an area outside the zones)
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?
- The interior of the bath or shower tray itself — the area always in contact with water (Correct answer)
- The area above the bath
- The entire bathroom floor area
- The area within 0.6 m of any water outlet
Correct answer: The interior of the bath or shower tray itself — the area always in contact with water
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?
- IPX7 (protection against temporary immersion) (Correct answer)
- IPX4
- IPX2
- IP44
Correct answer: IPX7 (protection against temporary immersion)
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?
- 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 (Correct answer)
- The area within 0.6 m horizontally outside the bath
- The area of the entire bathroom floor
- The area behind the bath panel
Correct 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
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?
- Only equipment with a minimum IPX4 rating, supplied at SELV, or shower units and bath heaters rated for Zone 1 use (Correct answer)
- Any standard equipment
- No electrical equipment of any kind
- Only battery-operated equipment
Correct answer: Only equipment with a minimum IPX4 rating, supplied at SELV, or shower units and bath heaters rated for Zone 1 use
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.
Question 6: What is Zone 2 in a bathroom?
- The area extending 0.6 m horizontally from the edge of Zone 1 and up to 2.25 m in height (Correct answer)
- The area directly above the shower head
- The entire bathroom beyond Zone 1
- The area below the bath
Correct answer: The area extending 0.6 m horizontally from the edge of Zone 1 and up to 2.25 m in height
Zone 2 extends 0.6 m horizontally beyond the boundary of Zone 1 (or the shower tray/enclosure) and up to 2.25 m in height, representing the area where water splashing is likely but immersion is not.
Part P Bathroom Zone Regulations 1
How many zones are defined in a bathroom containing a fixed bath under BS 7671?