Socket Faceplates: Finishes, USB-C, and the Back Box Depth Trap
UK guide to socket faceplates: white plastic from £1.65, brushed chrome from £7, USB-C sockets, brand quality rankings, and how many you actually need per room.
You spend months agonising over your kitchen layout, your worktop material, your tile choice. Then your electrician asks "what sockets do you want?" two days before second fix starts. You panic, order the cheapest white plastic ones from Screwfix, and six months later you're staring at grubby white rectangles on your brand-new brushed-chrome-and-slate kitchen walls. Or worse, you order beautiful USB sockets online, your electrician tries to fit them, and they won't go in because your back boxes are 10mm too shallow. Now he's chasing out 20 walls after the plasterer has finished.
Socket faceplates are one of the few materials in your extension that you'll look at and touch every single day. Get the decision right and they disappear into the room. Get it wrong and they irritate you for years.
What it is and what it's for
A socket faceplate is the visible front plate of an electrical socket outlet. It's the part you plug things into. Behind it sits a back box (a metal or plastic enclosure chased into the wall) containing the wiring connections. The faceplate screws into the back box, covering the wiring and providing the actual plug receptacle.
Every socket in your extension consists of two parts: the back box (installed during first fix, before plastering) and the faceplate (installed during second fix, after plastering and decorating). The back box is hidden inside the wall. The faceplate is what everyone sees.
All UK socket faceplates comply with BS 1363, the British Standard for 13A plugs and socket outlets. This mandates the distinctive three-rectangular-pin design, integral shutters on the live and neutral holes (so children can't poke things in), and standard dimensions: 86mm x 86mm for a single gang (one socket), 147mm x 86mm for a double gang (two sockets). Any BS 1363 faceplate fits any BS 4662 back box. Brands don't need to match.
Types and configurations
Single gang vs double gang
A single gang socket has one 13A outlet. A double gang (2-gang) has two. Double gang sockets are the default for almost every position in a modern extension. Single gang sockets go where space is tight: narrow walls, inside cupboards for fused spurs feeding built-in appliances, and beside beds where you want a compact profile at pillow height.
For new-build work, there's no good reason to use singles where a double would fit. The cost difference is negligible (often under under £1) and you'll never regret having the second outlet.
Switched vs unswitched
Most UK domestic sockets are switched, with a rocker switch above each outlet. Unswitched sockets exist but they're uncommon in homes. You'll find them in commercial settings or behind appliances that stay permanently plugged in (fridges, freezers). For your extension, buy switched sockets everywhere.
Single pole vs double pole switching
This one catches people out. A single pole (SP) switch only breaks the live wire when you turn it off. A double pole (DP) switch breaks both live and neutral. DP is marginally safer because it fully isolates the appliance from the mains.
BS 7671 doesn't require switches on socket outlets at all, so both types are legal. The cost premium for DP is negligible. Use DP sockets in kitchens where appliances like kettles and toasters draw heavy current. SP is fine everywhere else.
USB-integrated sockets
These have one or two USB charging ports built into the faceplate alongside the standard 13A outlets. Three options exist:
- USB-A only - the older rectangular USB connector. Charges phones and tablets but USB-A is disappearing from new devices. Buying USB-A sockets in 2026 means you'll want to replace them by 2030.
- USB-A + USB-C - one port of each type. The sensible middle ground right now. Budget models start around ~£9.
- USB-C only - both ports are USB-C. Future-proof but the most expensive option. Premium fast-charge models run to £43 – £46.
Don't fit USB-A-only sockets in a new extension. USB-C has won. Every phone, tablet, and laptop released since 2023 charges via USB-C.
USB sockets need deeper back boxes than standard sockets. The electronics behind the USB ports take up space. A standard 25mm back box is too shallow for most USB models. Your electrician needs to fit 35mm back boxes (minimum) at every position where you plan USB sockets. This decision happens during first fix, weeks before you choose your faceplates. If your back boxes are already in at 25mm, you're either buying spacer plates (which push the socket out from the wall) or your electrician is re-chasing finished walls.
Finishes: what to choose and why it matters
The finish you pick affects the cost per socket by a factor of five or more. It also determines whether your sockets blend with your interior or stick out like a plasterer's radio.
Brushed chrome is the safest all-round choice. It hides fingerprints better than polished chrome, suits both modern and traditional interiors, and costs less than stainless steel. That's why it dominates the extension market.
Matt black looks striking in a contemporary kitchen but has a practical weakness: limescale shows on dark surfaces in hard water areas. If you're in London, the Home Counties, or anywhere with chalk aquifer water, matt black sockets near the sink will need regular wiping.
Match your socket finish to your door handles, tap finish, and cabinet hardware. If you've got brushed nickel handles, brushed chrome sockets are the natural pair. If your taps are matt black, matt black sockets tie the room together. The consistency matters more than any individual finish choice.
Screwless vs screwed faceplates
Standard faceplates have two visible screws on the front face. Screwless (flat-plate) faceplates hide the screws behind a clip-on trim plate, giving a cleaner, slimmer profile.
The screwless design uses a two-part system: a metal backplate screws into the back box as normal, then a decorative trim plate clips over the top. This actually makes decorating easier. When the painter arrives, they pop off the trim plate (two seconds, no screwdriver) and paint right up to the backplate. Clip the trim back on after. With screwed faceplates, painters have to mask around them or unscrew each one.
Screwless sockets cost £2 – £5 more each than their screwed equivalents. On 25 sockets across an extension, that's £50 – £125 extra. For a project costing tens of thousands, it's not the place to cut corners.
Screwless faceplates need the wall surface to be flat and true. If the plaster is uneven, the trim plate won't sit flush and you'll get visible gaps around the edges. Flag this to your plasterer. Any wall receiving screwless sockets needs a clean, flat finish around the back box positions.
How many sockets do you need?
There's no legal minimum number of sockets in England or Wales. BS 7671 (the Wiring Regulations) includes Table H7 with recommended minimums, but these are guidance, not law. Scotland is different: Building Standards Section 4.6.4 mandates minimum socket counts per room.
The BS 7671 guidance figures represent bare minimums. Every builder, electrician, and homeowner forum in the country says the same thing: double whatever number you think you need.
The most common regret on extension forums is not installing enough sockets. One Mumsnet poster reported having 11 double sockets in their kitchen, with most in constant use. Socket positions must be decided during first fix (before plastering) because adding them afterwards means chasing out finished walls, re-plastering, and re-decorating.
Positioning rules
Your electrician knows these, but you should too:
- Minimum 450mm above floor level (accessibility requirement)
- Minimum 350mm from room corners
- Kitchen worktops: minimum 100mm above worktop surface, minimum 300mm from the edge of the sink
- Bedside sockets: 750-800mm above floor level puts them at mattress height for easy reach
- Inside cupboards for built-in appliances (fridge, dishwasher, washing machine) so the socket is accessible without pulling the appliance out
Which brands to trust
Not all sockets are made equal. Professional electricians are remarkably consistent about which brands they rate and which they avoid.
BG (British General) is the trade default. Acceptable quality at budget prices. The BG Nexus Metal range in brushed steel sits around £7 – £10 per double socket and is the most commonly specified finish for extension work. Multi-packs (5-pack of white double sockets for around ~£12.49) bring the per-unit cost down further.
MK was once the industry gold standard. The name still carries weight, but working electricians increasingly say MK trades on reputation rather than current quality. MK white plastic double sockets run £4 – £5 each, a noticeable premium over BG for what many professionals consider equivalent performance.
Hager gets the highest praise from professional electricians. The screw orientation, the terminal quality, the general feel. Hager sockets aren't in every retailer, so you'll pay a small premium, but electricians genuinely prefer fitting them.
Varilight dominates the screwless premium market. Their V-Pro range offers brushed chrome, polished chrome, and matt black in a slim flat-plate design. Reliable. A set of 20 Varilight screwless sockets runs to £200 – £300 depending on finish, but they look sharp.
Schneider (formerly GET) is well-regarded by the trade. Their Ultimate range in screwless white or metal finishes competes directly with BG Nexus Metal on quality and price.
Avoid LAP for longevity. LAP is Screwfix's budget own-brand line and it's the cheapest option on the shelf, but professional electricians report consistent failure problems. Switches stop clicking positively, terminals loosen, rocker mechanisms wear out. BG Essentials costs pennies more and doesn't have these issues. The saving isn't worth the callback.
Knightsbridge gets mixed reviews. Their decorative ranges look good and their IP66 outdoor sockets are well-regarded, but some electricians report durability concerns with their cheaper indoor ranges. If you're buying Knightsbridge, stick to their mid-range and above.
Cost and where to buy
Socket faceplates are available everywhere. Screwfix and Toolstation carry the widest range at trade prices. Wickes and B&Q stock the popular finishes in BG and their own-brand ranges. For premium brands like Varilight or specific designer finishes, specialist online retailers like Elesi or Soholighting carry broader ranges.
Buy in bulk. A typical kitchen extension needs 20-30 socket faceplates (plus switch faceplates, dimmers, and spurs). At those quantities, the difference between £2 and £10 per socket is £160 – £240 across the whole project. Meaningful, but context matters: your kitchen units cost thousands.
Order all your sockets from the same batch at the same time. Metal finishes can vary slightly between production runs, especially brushed chrome. A socket bought in March might not quite match one bought in June. Order 10-15% extra to cover breakages and future changes, and keep the spares for when you add a shelf or move furniture.
For outdoor sockets, the product cost is only part of the picture. An IP66 weatherproof socket is £10 – £30 for the unit, but the full installation (product plus electrician) runs £85 – £215 because outdoor circuits are notifiable work under Part P and require RCD protection.
Building regulations: when you need an electrician
Swapping a faceplate like-for-like (same type, same position, no wiring changes) is not notifiable work. You can do it yourself. Turn off the circuit at the consumer unit, test the socket is dead with a voltage tester, swap the plate, restore power.
Anything beyond a straight swap gets into Part P territory.
Adding sockets in a kitchen is notifiable work under Approved Document P, even if you're adding a spur off an existing circuit. Kitchens are classified as "special locations" alongside bathrooms and outdoor areas. Your electrician must either be registered with a competent person scheme (NICEIC, NAPIT, ELECSA) or you must notify Building Control before work starts. The same applies to any outdoor socket installation.
Adding a socket to an existing circuit in a bedroom or living room (not a special location) is generally not notifiable, provided the work is done competently. But every new circuit in your extension, including the ring mains that feed your sockets, is notifiable work regardless of location. In practice, all the socket circuits in your extension will be installed by a registered electrician and signed off with an Electrical Installation Certificate.
All socket circuits rated 32A or less in domestic properties now require 30mA RCD protection under BS 7671 (18th edition). This is handled at the consumer unit, not at individual sockets. You don't need RCD sockets unless you're adding an outdoor socket to an older circuit that lacks RCD protection at the board.
Alternatives and related materials
Switch faceplates use the same design language and come from the same manufacturers. Buy your switches and sockets from the same range so the finish, profile, and trim style match across the room.
Fused connection units (FCUs) are used instead of socket outlets for permanently wired appliances like extractors, heated towel rails, and under-cabinet lighting. They look similar to a socket faceplate but have a small fuse carrier instead of a 13A outlet. Available in matching finishes.
Floor sockets sit flush in the floor surface and open via a hinged or sliding lid. Useful under dining tables for laptop charging. They're more expensive (£25 – £60) and need a floor void for the back box, but they eliminate the cable trailing across the floor from a wall socket.
Airtightness: the hidden issue in extensions
This one is buried in building forums and almost never appears in buying guides. In a new extension with insulated walls (either cavity insulation or internal insulated plasterboard), cold air can bypass the insulation by travelling through the gap between the back box and the plasterboard. The socket becomes a draught point.
The fix is simple: foam sealant around the back box during first fix, before the plasterboard goes on. Your electrician and dryliner should both know this, but on a fast-moving site it gets missed. If you feel cold air coming through your sockets after the build, that's the cause.
Mention airtight back box sealing to your electrician at the start of first fix. Purpose-made airtight back box enclosures exist (brands like Novia and Visqueen make them), but a bead of expanding foam around a standard metal back box achieves the same result.
Common mistakes
Choosing sockets after back boxes are fitted. Your back box depth must match your faceplate type. Standard raised-profile sockets fit 25mm boxes. Screwless flat-plate sockets and anything with USB need 35mm minimum. Tell your electrician what style of faceplate you want before first fix starts. Not during second fix.
Inconsistent finishes in the same room. A brushed chrome double socket next to a white plastic fused spur looks careless. Buy every accessory in the same room from the same range. That includes blank plates, data points, TV outlets, and fused connection units.
Not enough sockets in the kitchen. Every kitchen extension forum thread, without exception, has someone saying they wish they'd put in more. Worktop sockets spaced at maximum 1m intervals. Dedicated outlets for every fixed appliance. Socket inside every tall cupboard. A spare pair at each end of the run for appliances you haven't bought yet.
Buying USB-A in 2026. USB-A is the old rectangular port. USB-C is the current standard for phones, tablets, laptops, and increasingly everything else. Fitting USB-A sockets in a new build is buying obsolescence.
Forgetting sockets for specific positions. Inside the under-stairs cupboard for the router and smart home hub. Inside the media wall for the TV. At floor level behind where the Christmas tree goes. Behind the bathroom mirror for the electric toothbrush charger. Walk through your daily routine room by room and list every device that needs power.
Where you'll need this
- Second fix electrics - socket faceplates are fitted after plastering and decorating, during the second fix electrical stage
Socket faceplates appear across any extension or renovation project that includes electrical work. The choices described here apply to kitchen extensions, loft conversions, garage conversions, and whole-house rewires. The planning (how many, what finish, what depth back box) happens during first fix. The physical fitting happens during second fix.