A grid switch system is three separate parts — modules, a faceplate and a back box — that you combine to build exactly the plate you need, instead of hunting for a pre-made switch that happens to match.
Four things to switch above a worktop? One plate, four modules. A fan isolator, a boiler switch and two spare positions? Same plate, different modules.
It is the answer to every wall that would otherwise end up with three mismatched switches next to each other.
1. The three parts, and why they are separate
The module is the working part — a switch, an isolator, an indicator, or a blank. It clips into the frame.
The faceplate is what you see, and it comes sized for a set number of module positions in whatever finish the room needs.
The back box is a standard box, sized to the plate.
Because they are separate, the finish decision and the function decision stop fighting each other. You are no longer looking for "a 2-gang 20A DP switch in brushed chrome" as a single product and finding it does not exist — you buy a 2-gang brushed chrome grid faceplate and two 20A DP modules.
Knightsbridge GDM002U — 20AX DP Grid Module, Double Pole Switch, White, ABS, IP20, 230V. The workhorse module: a 20AX double-pole switch, which is what most fixed appliances above a kitchen worktop actually need. Buy as many as you have appliances.
2. Sizing the faceplate
Count the functions, add at least one, and buy that many positions. The spare is not waste — it is the difference between adding an appliance in three years and re-doing the whole plate.
Knightsbridge GDFP002BC — 2 Gang Grid Faceplate, Flat Plate, Brushed Chrome, Premium Steel, IP20, 87.5mm x 87.5mm. Two positions in a standard 87.5mm square plate — the same footprint as an ordinary single accessory, so it drops into a standard single back box position.
Knightsbridge GDFP003BC — Flat Plate 3G Grid Faceplate, Brushed Chrome, IP20, Premium Grade Steel, 147.5mm x 87.5mm. Three positions at 147.5mm x 87.5mm — the double-width plate. This is the one that replaces the row of assorted switches above a kitchen worktop with a single line.
Trade Tip: the faceplate size tells you the back box you need, and a grid plate almost always wants more depth than the accessory it is replacing. Sort the box out while the wall is open. Going back to deepen a box behind a finished plate means making good twice.
3. Where grid earns its keep
Kitchens. Hob, oven, extractor, dishwasher, washing machine — five appliances that each want isolation, and without grid you get five separate plates marching along the wall.
Plant rooms and utility spaces. Where you want everything switchable from one place and clearly laid out.
Commercial and rented property. Where a key-operated module can sit alongside ordinary switches on the same plate, so the things that should not be casually switched are not.
Knightsbridge GDM021BC — 10A Fan Isolator Key Switch Module, Key Switch Operation, 230V, IP20, Brushed Chrome. A fan isolator as a grid module, operated by key. It sits in the same plate as the ordinary switches but cannot be flipped by whoever is standing there. More on the isolator itself in the fan isolator guide.
4. Blanks, and future-proofing
A blank module fills an unused position so the plate looks finished and nothing is exposed. It is the cheapest part of the system and the one most worth over-ordering.
Knightsbridge GDM013MW — Blank Grid Module, Clip-In Design, Durable ABS, Matt White, IP20, 230V, Internal Use. The blank. Buy a spare position on the plate, fill it with one of these, and adding a switch later is a five-minute job with the power off rather than a new plate, a new box and a repaint.
Trade Tip: label the modules before the plate goes back on, even roughly, even in pencil on the back box. Six identical rockers above a worktop with nothing to distinguish them is how you end up switching the freezer off looking for the extractor.
5. Finish, and mixing with the rest of the room
Grid faceplates come in the same finishes as the standard ranges — flat plate brushed chrome, polished chrome, metalclad for workshops and plant rooms. Choose to match the sockets and switches already in the room, not the appliances.
Summary: specifying a grid switch plate
| Step | What to decide |
|---|---|
| 1. Count | How many functions need switching — then add at least one spare |
| 2. Faceplate | Size to that count; 2-gang is 87.5mm square, 3-gang is 147.5 x 87.5mm |
| 3. Modules | 20AX DP for appliances, fan isolator, key switch where control matters |
| 4. Blanks | One per unused position |
| 5. Back box | Sized to the plate, and deeper than you think — sort it while the wall is open |
Expert Help in the West Midlands
Villa Road, Birmingham, since 1975. Grid is the system where a two-minute conversation saves an hour on site — tell us the appliances and the finish and we will list the modules, the plate and the box so nothing is missing when you open the bag.
See switches and controls for the full grid range, and back boxes and pattress boxes for the box behind it.
Grid switch FAQs
What is a grid switch system?
A modular system where the switch mechanisms, the faceplate and the back box are bought separately and combined. It lets you build one plate holding exactly the functions you need, in the finish you want.
Can I add a module to an existing grid plate later?
Yes, provided there is a spare position. That is what blank modules are for — fit the plate with a spare from the start and adding a function later is a quick job with the circuit isolated.
Do grid switches need a special back box?
A standard back box sized to the faceplate, but usually a deeper one than the accessory it replaces. Check the depth requirement before you fix the box, not after the plate arrives.