Special Locations (BS 7671 Part 7)
Special installation requirements for bathrooms, swimming pools, construction sites, and other locations
Bathrooms and Shower Rooms — Section 701
The most commonly encountered special location. Zone classification determines what equipment and wiring is permitted.
Bathroom zone requirements
BS 7671 Section 701| Zone | IP Rating | Permitted Equipment | Voltage |
|---|---|---|---|
| Zone 0 | IPX7 | Fixed SELV equipment only | Max 12V AC SELV |
| Zone 1 | IPX4 (IPX5 with jets) | Water heaters, showers, SELV items | SELV or 230V fixed (RCD) |
| Zone 2 | IPX4 | Luminaires, shavers, fans (Class II) | 230V with 30mA RCD |
| Outside zones | General | All equipment (with RCD) | 230V with 30mA RCD |
All circuits serving the bathroom require 30mA RCD protection regardless of zone.
Supplementary Bonding Exemption
Swimming Pools — Section 702
Swimming pools and surrounding areas have the most restrictive requirements of any special location.
Swimming pool zone restrictions
BS 7671 Section 702| Zone | Requirements | Permitted Wiring |
|---|---|---|
| Zone 0 (pool basin) | SELV 12V AC / 30V DC only | Cables supplying Zone 0 equipment only |
| Zone 1 (1.5m beyond pool edge, 2.5m height) | SELV or 230V with RCD + IPX4/X5 | Mineral insulated, armoured, or behind barriers |
| Zone 2 (next 1.5m) | 30mA RCD, IPX2 min | Standard wiring methods permitted |
The SELV source (safety isolating transformer) must be installed outside Zones 0 and 1. No switching devices are permitted in Zones 0 or 1. Socket outlets are not permitted within 1.25m of Zone 1 in domestic pools.
Construction Sites — Section 704
Temporary electrical installations on construction sites must address the high-risk environment: wet conditions, mechanical damage, and use by many operatives. The primary safety measure is reduced voltage via 110V centre-tapped transformers.
Construction site voltage requirements
BS 7671 Section 704| Application | Voltage | Protection |
|---|---|---|
| Portable hand tools | 110V CTE (55-0-55V) | BS 4343 transformer |
| Portable hand lamps | 25V SELV (or 50V) | Safety transformer |
| Fixed floodlighting | 230V | 30mA RCD + 0.4s disconnection |
| Site offices / cabins | 230V | 30mA RCD on all socket outlets |
TT Earthing on Construction Sites
Other Key Special Locations
Overview of commonly encountered special locations
BS 7671 Part 7| Section | Location | Key Requirement |
|---|---|---|
| 706 | Confined / restrictive spaces | SELV only or Class II equipment |
| 708 | Caravan / camping parks | Each pitch: IP44 socket, 30mA RCD, 16A min |
| 711 | Exhibitions / shows | Temporary wiring, 30mA RCD, daily inspection |
| 722 | EV charging | Dedicated circuit, Type A/B RCD, PME earthing check |
| 740 | Temporary structures (fairs) | As Section 711 plus mechanical protection |
Always check the full section — this table summarises the primary requirement only.
Identifying Special Locations