A standard indoor socket fitted outside a back door because it was already on the van is not a shortcut. It's a failed EICR waiting to happen.

What do the two IP rating digits actually mean?

IP stands for Ingress Protection, and the rating is always two digits. The first digit covers solid object and dust protection, on a scale of 0 to 6. The second covers liquid protection, on a scale of 0 to 9. An IP44 socket has a 4 for dust (protected against tools and wires over 1mm) and a 4 for water (protected against splashing from any direction). An IP66 fitting jumps to a 6 on both, fully dust-tight and protected against powerful water jets.

Higher numbers always mean tougher, never the other way round. There's no situation where a lower-rated fitting outperforms a higher one in the same location, the rating is a floor, not a style choice.

Which IP rating does each room actually need?

This is where most mistakes happen, usually from treating "indoors" as one category when it isn't.

Outdoor sockets: why IP66 and not IP44?

IP44 protects against splashing from any direction, but it doesn't cover sustained direct rain or pressure washing. A socket on an exterior wall with no canopy or overhang gets all of that over a UK winter, so IP44 will eventually let moisture in regardless of how well it's installed.

IP66 is dust-tight and rated against powerful water jets from any angle, which is the realistic spec for anything bolted to an outside wall in a property in, say, a coastal town in North Wales where driven rain off the sea is a daily event rather than an occasional one. Covered areas, a porch or car port with an overhang, can usually drop to IP44 or IP55 since they're shielded from direct rain even if the air around them is damp.

IP44 vs IP66: which one actually holds up?

For a garden office or shed installation, a project that's become common across UK back gardens since 2024, IP66 weatherproof sockets at the building's exterior connection point are the standard spec, with IP20 fine once you're inside the dry, insulated structure itself.

Does IP rating affect BS 7671 compliance on an EICR?

Yes, directly. An Electrical Installation Condition Report assesses whether existing wiring accessories meet the requirements for their location, and an under-rated socket or switch in a bathroom zone or exterior location gets coded as a defect, potentially a C2, requiring remedial action before the property passes. This applies whether the original installer made an honest mistake or just used what was on the van that day.

Specifying the correct IP rating at install avoids the cost of someone else finding the problem at the next EICR cycle, typically every five years for rented and let property under current Brown Book guidance.

Frequently Asked Questions