There is no single regulation that says "a socket must be 300mm from a sink". It's guidance rather than law, widely followed, and repeated online as though it were statutory. Meanwhile the requirement that genuinely does apply — that you must be able to isolate an appliance — gets almost no attention at all.
Worth separating the two, because a kitchen can meet every piece of folklore about socket positions and still be badly designed.
The Short Answer
The actual requirement is that every appliance has a safe, accessible means of isolation. How you achieve that is flexible. Where you put it is not really negotiable — it has to be reachable with the appliance in place.
Widely followed guidance, not statute:
- At least 300mm horizontally from a sink, measured from the edge of the bowl or drainer
- Not directly above a hob, where you'd reach across a pan to use it
- Around 150mm above the worktop for accessible sockets, and 450mm to 1200mm above floor level in general use areas
Sockets behind integrated appliances are permitted and are extremely common. They're also a poor choice, because the socket becomes unreachable and sits against a warm appliance. The better answer is a socket in the adjacent cupboard, or a switched fused spur above the worktop.
What is not optional: RCD protection for socket circuits in modern installations, and — if you're adding any new socket — using a registered electrician, because a new cable run is notifiable work.
What Actually Matters
Three principles sit underneath all the specific numbers.
Isolation you can reach. The whole purpose of the socket or switch is that someone can cut power to the appliance quickly and safely. A socket behind a fitted dishwasher fails this test completely — reaching it means pulling the machine out, which is exactly what you can't do when water is coming out of it. This is covered further in the piece on isolation switches above the worktop.
Distance from water. The 300mm figure is about splash zones rather than a hard electrical boundary. Kitchens aren't classified as special locations the way bathrooms are, so there's no zoning regime — but water and sockets remain a poor combination and the guidance exists for obvious reasons.
Distance from heat. A socket above a hob puts your arm over a pan. A socket behind an oven or against a fridge condenser sits in warm air permanently, which degrades the plug and the faceplate over years. Heat is the slower of the two problems and the more commonly ignored.
Detailed Analysis
The 300mm rule, explained properly
This comes from industry guidance rather than the wiring regulations themselves. It suggests keeping socket outlets at least 300mm horizontally from the edge of a sink or drainer.
It's sensible and nearly universal in practice. It is not, however, a legal minimum, and electricians will occasionally install closer where a kitchen genuinely leaves no alternative — typically with the socket positioned so that splashing cannot reach it directly, or by substituting a switched fused spur which has no exposed openings.
Where people go wrong is measuring from the tap rather than the bowl edge, or forgetting that a drainer counts. Measure from the furthest edge of the wet area.
Heights, and where they come from
For new-build and substantially refurbished homes, Part M of the Building Regulations requires socket outlets in habitable rooms to be between 450mm and 1200mm above floor level, for accessibility. It applies to new dwellings rather than to replacing sockets in an existing kitchen.
Above a worktop, the practical convention is roughly 150mm clear of the surface. Lower and plugs foul the worktop; higher and they intrude on the splashback and wall units.
Under-worktop sockets serving integrated appliances have no height rule as such, but they should be positioned where a plug can be reached without dismantling anything — usually in the neighbouring cupboard rather than directly behind the machine.
Hobs, ovens and the reaching problem
The rule here is behavioural rather than electrical. A socket or switch positioned above a hob means someone reaches over a hot pan to use it, potentially in a hurry.
Convention places cooker control units to one side of the hob and slightly above worktop height. Never centred above it. The same logic applies to any socket on a splashback behind a hob.
Ovens have a different issue: heat. A socket in the housing directly behind a built-in oven sits in the hottest available spot and is inaccessible. Where an oven runs on a plug — which it can if it's rated under about 3kW, as covered in the piece on cooker switches — the socket belongs in the adjacent cupboard.
Behind integrated appliances
Nothing forbids a socket behind an integrated fridge, dishwasher or washing machine, and it's how a large proportion of British kitchens are built.
The problems are practical. You cannot reach it. It sits in warm air. The plug can work loose as the appliance is pushed back and nobody notices. And when something goes wrong, isolating the appliance means either finding the right breaker or pulling out a machine that may be leaking.
The better arrangements are a socket in the adjoining cupboard, so the appliance can be unplugged through the base unit, or a switched fused spur above the worktop with the appliance flex connected below. The specific case of a fridge freezer has its own considerations, since fridges reject heat continuously and are the appliance you least want to unplug by accident.
How many sockets, and on what
Provision is chronically inadequate in most kitchens, and that shortage is the direct cause of extension lead use — which is where kitchen electrical problems actually concentrate.
A worktop run wants more double sockets than seems necessary, spread along its length rather than clustered at one end. Two of them should be far enough apart that a kettle and a toaster don't end up in the same double socket, since a double socket is designed for around 20A total rather than two full 13A outlets.
Whether those sockets sit on a ring or a radial affects the circuit's capacity, and is worth understanding before deciding a kitchen needs rewiring — see ring main versus radial. Appliances that draw heavily for hours may warrant a circuit of their own.
Real-World Considerations
Refits are when this gets decided, and it's usually decided by where the old sockets happened to be. Moving them is far cheaper while the units are out than afterwards, and the layout should be planned around the appliances rather than inherited from the previous kitchen.
Grid switches — the row of small switches above the worktop in most fitted kitchens — are the standard solution to under-counter appliances. They work well and they are almost never labelled, which halves their usefulness. Labelling them during installation takes two minutes.
Islands are a particular problem, since there's no wall. Options are limited to sockets in the island's end panel, pop-up units in the worktop, or sockets under an overhang. All three have drawbacks and all three need the supply routing through the floor, which has to be planned before the floor goes down.
Older kitchens frequently share a circuit with the rest of the ground floor. If your kitchen sockets and living room sockets trip together, that's what you have, and the effective capacity is lower than it appears.
One last practical point: sockets get wet in kitchens regardless of where you put them. A splashback socket behind a worktop that gets wiped daily will accumulate moisture around the faceplate over years. It's an argument for spurs over sockets in the wettest positions, and for checking faceplates occasionally for discoloration.
Common Mistakes Buyers Make
- Treating the 300mm figure as law. It's guidance. Useful, widely followed, not statutory — and knowing that helps when a kitchen genuinely can't accommodate it.
- Putting the socket behind the appliance it serves. Legal, common, and useless when you need it.
- Centring a switch above the hob. Nobody should reach across a pan to isolate something.
- Not labelling grid switches. Five unlabelled switches means guessing during an emergency.
- Planning sockets from the old kitchen's positions. The refit is the moment to fix them, and it costs almost nothing extra then.
- Adding a socket as a DIY job. A new cable run in a kitchen is notifiable work and needs a registered electrician.
- Fitting too few and relying on extension leads. The shortage causes the overloading, and heating appliances should never be on a lead.
- Forgetting the island entirely until the floor is down. The supply has to be routed before that point.
Alternatives Worth Considering
A switched fused spur is often better than a socket for integrated appliances. It gives local isolation with a switch you can reach, no plug to work loose, and no exposed openings to collect moisture. Fitting one to an existing circuit is generally not notifiable.
Grid switch modules handle several under-counter appliances from one plate above the worktop. They're the standard fitted-kitchen answer and worth specifying deliberately, with labels.
Pop-up worktop sockets solve the island problem and keep splashbacks clear. They're a moving part in a wet environment and they cost considerably more than a wall socket, so they suit islands and not much else.
And where an existing kitchen is simply short of sockets, adding to the existing circuit is usually straightforward work for an electrician — an alteration rather than a new circuit in many cases, though the notification position depends on exactly what's done and where.
Frequently Asked Questions
How far must a socket be from a kitchen sink?
Industry guidance suggests at least 300mm horizontally from the edge of the sink or drainer. It's widely followed convention rather than a legal minimum.
Can a socket be behind a washing machine?
Yes, it's permitted and common. It's a poor choice because you can't reach it to isolate the appliance, and a socket in the adjacent cupboard is far more useful.
Can you put a socket above a hob?
You shouldn't. It means reaching over hot pans. Cooker switches go to one side, slightly above worktop height.
What height should kitchen sockets be?
Roughly 150mm above the worktop by convention. In new-build homes, Part M requires sockets between 450mm and 1200mm from floor level.
Do kitchen sockets need RCD protection?
In modern installations, yes. Older installations may not have it, which is a reasonable prompt to have the consumer unit assessed.
Can I add a kitchen socket myself?
No. A new cable run is notifiable work under Part P and needs a registered electrician or a building control application.
Final Thoughts
The specific numbers are worth knowing, but the principle underneath them is more useful: every appliance needs isolation somebody can actually reach, and sockets should be away from water and away from heat.
A kitchen that satisfies those three things will comply with the guidance almost automatically. A kitchen designed around where the old sockets were will meet the letter of the 300mm rule and still leave you pulling out a leaking dishwasher to find the plug.
For the wider picture of what you can and can't do yourself, see the main guide to fitting kitchen appliances.
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