Part P Bathroom Zone Regulations 3

Question 1

What is a shower zone and how does it differ from a fixed bath zone?

Accepted Answer

A shower zone (without a tray) extends to 1.2 m radius from the shower head and 2.25 m height; a fixed bath zone follows the plan dimensions of the bath

Answer

For a shower without a tray, BS 7671 Section 701 defines Zone 1 as a cylinder of 1.2 m radius from the shower outlet and 2.25 m height; Zone 2 extends a further 0.6 m from the Zone 1 boundary.

Question 2

Can a luminaire (light fitting) be installed in Zone 1 of a bathroom?

Accepted Answer

Yes, if it has a minimum IP rating of IPX4 and is suitable for use in Zone 1 (or higher-rated SELV luminaire)

Answer

Luminaires rated at least IPX4 may be installed in Zone 1; they must be appropriate for the zone, with no user-serviceable lamp without a tool, and connections within the fitting must be adequately protected.

Question 3

Are heating appliances permitted in bathroom zones?

Accepted Answer

Yes — specifically designed electric towel rails, fixed heaters and under-floor heating designed and rated for the relevant zone are permitted

Answer

Fixed electrical heating (towel rails, panel heaters, under-floor heating) is permitted in bathroom zones provided the equipment is specifically designed and rated for the zone (correct IP rating and thermal suitability).

Question 4

What RCD protection is required for circuits supplying bathroom zones?

Accepted Answer

All circuits supplying equipment in bathroom zones must be protected by a 30 mA RCD

Answer

BS 7671 requires all circuits that supply equipment within bathroom zones to be protected by a 30 mA RCD, providing additional protection against electric shock, recognising the increased shock risk in wet environments.

Question 5

Can a consumer unit be installed inside a bathroom?

Accepted Answer

No — consumer units must not be installed in rooms containing a bath or shower, as they contain live parts that are not adequately protected against water ingress

Answer

BS 7671 Section 701 prohibits the installation of consumer units (distribution boards) in rooms containing baths or showers, due to the risk from water ingress and the presence of unprotected live parts.

Part P Electrical Practice Test

Part P Electrical Practice Test

Part P Bathroom Zone Regulations 3