Special Locations in BS 7671: Bathrooms, Swimming Pools, and More

Part 7 of BS 7671 covers special installations or locations — places where the standard wiring rules alone don’t provide enough protection. Wet skin, immersion in water, conductive surroundings, restrictive working conditions, and outdoor exposure all change the risk profile, and Part 7 adds the extra requirements that compensate.

 

For the City & Guilds 2382-22 exam, Part 7 carries about 7 of the 60 questions — and the bulk of those come from a handful of sections rather than the full list. Knowing which sections to focus on, and where the zoning and RCD rules sit, is one of the most efficient uses of study time you can make.

 

This guide walks through the special locations you need to know, the figures the exam keeps returning to, and the traps that catch candidates out.

How Part 7 Works

The most important thing to understand about Part 7 — and the thing examiners love to test — is that it supplements Parts 1 to 6 rather than replacing them. Every requirement from the general parts still applies; Part 7 adds extra rules on top.

 

The numbering system mirrors that of the general parts. For example, Regulation 701.411.3.3 means:

 

Digit	Meaning
701	Section 701 (Locations containing a bath or shower)
411	Chapter 41 (Protection against electric shock)
3.3	Specific regulation within that chapter

 

In other words, “701.411.3.3” is the bathroom-specific version of the general rule in 411.3.3.

 

Key point: If a Part 7 section is silent on a topic, the general rule in Parts 1–6 still applies. Part 7 only modifies what it explicitly addresses.

 

Section 701 — Bathrooms and Showers

By a wide margin, Section 701 is the most frequently examined special location. The reasoning is practical: bathrooms are the special location electricians work in most often, and the consequences of getting it wrong are severe — wet skin lowers the body’s resistance to around 1,000 Ω, compared to several thousand Ω when dry.

 

The Zones

Zone	Boundary	Minimum IP	Permitted Equipment
0	Interior of the bath or shower basin	IPX7	12V AC / 30V DC SELV only
1	Above Zone 0, up to 2.25 m above floor level	IPX4	Fixed equipment suitable for the zone (e.g. fixed shower, electric heater)
2	0.6 m horizontally beyond Zone 1, same height	IPX4	Shaver supply units (BS EN 61558-2-5), luminaires, fan heaters — no general sockets

 

For showers without a basin, Zone 1 is taken as a vertical cylinder 1.2 m radius from the showerhead, up to 2.25 m above floor level.

 

RCD Protection

Regulation 701.411.3.3 is the headline rule, and it’s blunt: every low-voltage circuit serving a location containing a bath or shower must have 30 mA RCD additional protection. That includes lighting, immersion heaters, towel rails, extractor fans, and any socket outlets outside Zone 2.

 

Supplementary Bonding

Supplementary equipotential bonding in bathrooms is only required where one or more of the conditions in Regulation 701.415.2 are not met. In modern installations with 30 mA RCDs throughout and proper main protective bonding, supplementary bonding can usually be omitted. For a deeper walkthrough, see our guide on supplementary bonding and touch voltage.

 

Exam tip: A common multiple-choice trap shows a shaver socket “in Zone 1” or “next to the bath” and asks if it’s compliant. Standard sockets are not permitted in Zones 0, 1, or 2. Shaver supply units to BS EN 61558-2-5 are permitted in Zone 2 because they provide isolation from earth.

 

Section 702 — Swimming Pools and Fountains

Section 702 applies to swimming pools, paddling pools, and the basins of fountains. The hazards are extreme — full body immersion, wet skin, and often bare feet on conductive surfaces.

 

The Zones

Zone	Area	Equipment Voltage Limit
0	Inside the pool basin and fountain water	12V AC / 30V DC SELV
1	2 m horizontally from the pool edge, 2.5 m above water/floor	SELV ≤ 25V AC / 60V DC, or specifically listed equipment
2	A further 1.5 m horizontally beyond Zone 1	Socket outlets only with specific protection (SELV, isolating transformer, or 30 mA RCD)

 

Note there is no Zone 2 for fountains — only Zones 0 and 1.

 

Key Requirements

Requirement	Detail
RCD protection	30 mA RCDs required for circuits supplying equipment in Zones 1 and 2
Supplementary bonding	Required to all extraneous-conductive-parts in Zones 0, 1, and 2
Equipment in Zone 0	Fixed equipment only, IPX8 minimum
Underwater luminaires	Must be SELV; for swimming pools the SELV source must be outside Zones 0, 1, and 2

 

Important: Supplementary equipotential bonding is not optional in pool locations the way it sometimes is in bathrooms. Section 702.415.2 requires it for all extraneous-conductive-parts in the zones, regardless of RCD protection.

 

Section 703 — Saunas

Saunas combine heat, sweat, and conductive wet surfaces. Section 703 defines four zones based on proximity to the heater and ambient temperature.

 

Zone	Description	Equipment
1	Around the sauna heater	Heater and its supply only
2	Below 1.0 m from the floor	No temperature restriction on equipment
3	Between 1.0 m from floor and the ceiling	Equipment rated for up to 125°C; cables up to 170°C

 

A 30 mA RCD is required for all circuits inside the sauna room except the sauna heater itself, which is permitted to be on its own circuit without RCD provided it is hard-wired.

 

Section 704 — Construction and Demolition Sites

Construction sites are temporary, exposed to weather, and full of conductive materials. Section 704 introduces the reduced low-voltage system familiar to anyone who’s used 110V site tools.

 

Requirement	Detail	Regulation
Reduced low voltage	110V centre-tapped to earth (55V to earth) for portable hand tools and hand lamps	Reg. 704.410.3.10
RCD — sockets ≤ 32A	30 mA	Reg. 704.411.3.2.1
RCD — sockets > 32A	500 mA	Reg. 704.411.3.2.1
Inspection interval	At least every 3 months	Reg. 704.6

 

The reduced low-voltage system is the key concept here. Reducing the voltage to 55V relative to earth means that a fault to earth produces a current too low to cause a lethal shock on dry skin — though the system is still designed to operate within the disconnection times of Chapter 41.

 

Remember: Site transformers for reduced low voltage produce 110V line-to-line, 55V line-to-earth. The “110V” you see on the yellow plug is the line-to-line figure.

 

Section 705 — Agricultural and Horticultural Premises

Livestock are more vulnerable to electric shock than humans — wet hooves, conductive concrete floors, and large contact areas all reduce body resistance. Section 705 reflects this with stricter protection requirements.

 

Requirement	Detail
Disconnection time (final circuits ≤ 32A)	0.2 s (compared to 0.4 s in standard TN installations)
RCD additional protection	30 mA for all socket outlets ≤ 32A; 300 mA for circuits supplying livestock areas (fire risk)
Equipotential bonding	Required for all extraneous-conductive-parts accessible to livestock
IP rating	IP44 minimum for outdoor and washdown areas; IP54 in dusty environments

 

The 300 mA RCD requirement for fire protection in livestock buildings catches candidates out — it’s a fire risk measure, not a shock protection measure, and it’s specifically required by Regulation 705.422.7.

 

Section 708 — Caravan and Camping Parks

Section 708 applies to the electrical supply to caravan pitches, motor caravan pitches, and tent pitches in commercial parks.

 

Requirement	Detail
Socket outlet rating	Each socket outlet not exceeding 16A (industrial blue 16A socket to BS EN 60309-2)
Sockets per pitch	One socket outlet per caravan/tent pitch
RCD	Each socket outlet protected by an individual 30 mA RCD
Overcurrent protection	Each socket outlet individually protected by an overcurrent device
Mounting height	Between 0.5 m and 1.5 m above ground level

 

The “individual RCD per socket” requirement is the headline rule — a single RCD covering multiple pitches would not comply, because a fault on one caravan would trip the supply to neighbouring pitches.

 

Sections 712, 722, and 753

These three sections cover modern installations that have grown rapidly in scope over the last decade. They appear less often in the exam than Section 701 or 704, but each typically generates at least one question.

 

Section 712 — Solar PV

Requirement	Detail
DC side cannot be isolated in daylight	PV modules generate voltage whenever exposed to light
DC isolation	Required at the array, with switch-disconnectors suitable for DC
Labelling	Warning labels required at consumer unit, meter position, isolators, and array
String fault protection	Where parallel strings are connected, string protection may be required

 

Section 722 — Electric Vehicle Charging Installations

Requirement	Detail
Dedicated circuit	One dedicated circuit per charging point
RCD	30 mA Type A minimum (or Type B if the EVSE does not protect against DC fault currents)
Continuous duty	Cables and protective devices rated for sustained full load — typically several hours
PME considerations	Specific provisions for protection against open-PEN faults on TN-C-S supplies

 

Section 753 — Floor and Ceiling Heating

Requirement	Detail
30 mA RCD	Required for all heating cable circuits
Temperature limit	Floor surface temperature must not exceed 35°C in normal areas (lower in bathrooms)
Bonding	Metallic grids and reinforcement integrated into the heated area treated as exposed-conductive-parts

 

Common Exam Pitfalls

Even candidates who’ve revised Part 7 carefully lose marks on the same handful of issues. Watch for these:

 

Pitfall	Why It Catches People
Forgetting Part 7 supplements Parts 1–6	Questions sometimes ask about a Chapter 41 rule in a bathroom context — both apply
Confusing IPX4, IPX5, and IPX7	IPX4 = splash, IPX5 = jets, IPX7 = temporary immersion. Each zone has a specific minimum
Mixing up Zone dimensions	Bathroom Zone 1 is up to 2.25 m; pool Zone 1 is 2.0 m horizontal and 2.5 m vertical
Forgetting 110V is line-to-line	The 55V figure is line-to-earth — both come up in exam answer choices
Missing the 300 mA agricultural RCD	It’s a fire protection rule, not a shock protection rule
Assuming RCDs eliminate the need for bonding	In pools and saunas, supplementary bonding is required regardless of RCD provision

 

Bottom line: Most Part 7 exam questions reduce to four facts about each section — zone definitions, voltage limits, RCD rating, and any bonding requirement. Build a one-page summary card for each section using exactly those four headings.

 

For a broader Part 7 overview that puts these sections in context, see our Guide to Part 7: Special Installations and Locations. For the underlying RCD theory you’ll need to apply across every section, our RCD Protection guide walks through the device types and trip characteristics. And if you’re still tightening your overall exam strategy, the 10 tips from qualified electricians covers the broader study plan.

 

Practice and Further Study

Part 7 is one of the areas where targeted practice pays off fastest, because the questions tend to test a relatively small set of specific facts.

 

• Part 7 — Special Installations quiz
• Part 4 — Protection for Safety quiz (RCD requirements link back here)
• Part 6 — Inspection and Testing quiz

 

Our app includes 580+ practice questions spanning every part of BS 7671, with full mock tests that match the real exam’s weighted distribution — meaning you’ll see Section 701, 704, and 722 questions in roughly the same proportions you’ll meet on the day.

 

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