Pottery Studio Electrical & Power Requirements (UK)

Part of Open Your Studio, our guide series for opening a pottery studio in the UK.

You've found a unit you like. The rent works, the light is good, the landlord seems reasonable. Then someone asks the question nobody in the room can answer: will the electrics take a kiln? It's the right thing to worry about. Of all the things that go wrong between signing a lease and opening the doors, power is the one we see most often. It has the longest lead time of anything in the fit-out, it's the hardest to fix once you've committed, and it's the most common reason an opening date slips.

The good news is that you don't need to become an electrician to get it right. You need to understand a handful of numbers, ask the right questions early, and know what the answers mean. We're not electricians either, so this guide won't tell you how to wire anything. It tells you what to ask yours. If you want a quick answer for your own building first, put your kiln and wheel count into the Studio Power Calculator and come back with the result.

Why electrics are the thing that moves your opening date

Almost everything else in a studio can be bought, delivered and set up in a few weeks. Wheels ship quickly. Benches and shelving can be built in a weekend. Electrics don't work like that, for three reasons.

First, the kiln can't be commissioned until its circuit exists. If the circuit is late, the first firing is late, and your first class has nothing to take home. Second, if the building needs a bigger incoming supply, or three-phase, that's a job for the local electricity network operator rather than your electrician, and new connections are quoted and scheduled on their timetable, not yours. Depending on the site and whether the street network needs work, that can take weeks or months. Third, you usually need the landlord's consent before anyone touches the installation, and that adds its own wait.

That's why our own planning timeline puts the electrician's survey at 12 or more weeks before opening, before you've fixed the kiln size, before you've ordered anything, and ideally before you've signed the lease. If you can, make the lease conditional on the supply being adequate, or at least get the survey done during negotiations.

Kilowatts to amps: the one sum worth knowing

Kilns are described in kilowatts (kW). Circuits are described in amps (A). To get from one to the other on a normal UK single-phase supply, divide the watts by 230 volts. A 3 kW kiln draws about 13 A. A 7 kW kiln draws about 30 A. That's the whole trick.

What makes kilns different from a kettle or a heater is that they draw close to that full current for hours at a time, often overnight. That's why a kiln of any real size gets its own dedicated circuit, and why "we'll just plug it in" isn't an option once you're past the smallest test kilns.

These are typical figures across the kilns we sell, not a substitute for the data plate. When you've shortlisted a kiln, give your electrician its actual spec sheet: rated kW, single- or three-phase, and how it connects. If you're still choosing, our guide to choosing a kiln for a studio and the Kiln Size Calculator will get you to a size first. Size and power need to be decided together.

Single-phase or three-phase?

Almost every house and many small commercial units have a single-phase supply: one live conductor, 230 V, protected by a main fuse at the meter. Ex-industrial units, workshops and some shops already have three-phase: three live conductors at 400 V between them, which spreads a big load across three lines. An 18 kW three-phase kiln draws roughly 26 A on each phase, instead of the 78 A it would need on one.

The kiln circuit is only half the question. The other half is the building's total load when everything runs at once: the kiln firing, a full class on the wheels, heaters on a January evening, lights, the extraction fan, the kettle. A modern electric wheel draws under 0.5 kW, so eight of them are a small part of the picture, and a big kiln plus electric heating is often what tips a single-phase building over. Two kilns firing together is where most growing studios run out of headroom.

So the questions are, in order: what does this building already have, how much is already spoken for, and does the kiln you want fit inside what's left? If the answer is no, you have three options: a smaller or lower-rated kiln, two smaller kilns that you don't fire at the same time, or a supply upgrade. We'd always rather help you pick a kiln that suits the building than sell you one that needs a three-month wait.

What each piece of kit needs

The kiln. Its own circuit, sized for that kiln, with a local isolator near it so it can be switched off safely for loading checks and maintenance. Small kilns on a 13 A plug still deserve a dedicated socket. No extension leads, no adaptors, no sharing with a heater.

The wheels. These are the easy bit. They run from ordinary sockets, but give the row of wheels its own circuit with RCD protection, and put the sockets above splash height, well away from the sink and the slop buckets. BS 7671 already expects 30 mA RCD protection on most general-use sockets up to 32 A, so a good electrician will do this anyway. Your job is to tell them where the wheels will sit so the sockets end up in the right place and no lead trails across a walkway.

Everything else. A pugmill, extraction fans, a dehumidifier in the kiln room, heating, lighting and the tea point. List it all for your electrician, even the small stuff, because it's the total that matters.

BS 7671, Part P and the paperwork

BS 7671, the IET Wiring Regulations, is the UK standard that new electrical work should meet. When your electrician adds a kiln circuit, ask for an Electrical Installation Certificate and keep it. Your insurer or landlord may well ask to see it. Ask too how often the installation should be inspected after that (a periodic inspection, or EICR), and put the date in the diary.

Part P of the Building Regulations covers electrical work in dwellings in England and Wales, including outbuildings and premises that share a supply with a home. Adding a new circuit there is notifiable work. If your studio is a garden building, a converted garage or a room in a house, use an electrician registered with a competent person scheme, who can self-certify and notify building control for you. A standalone commercial unit generally sits outside Part P. The work still has to be safe, and the Electricity at Work Regulations still apply to whoever runs the premises. Scotland and Northern Ireland have their own building rules. If you're not sure which applies, ask your electrician or local building control before the work starts.

One more piece of paperwork: the lease. Many commercial leases need landlord consent for alterations to the electrical installation, and some landlords want to approve the contractor. Ask early.

What to ask your electrician

Book the survey with the kiln spec sheet and a rough layout in hand. Then ask:

• What is the incoming supply here: single- or three-phase, and what's the main fuse rating?
• How much of that is already used, and can it carry the kiln at full load with everything else running?
• Does this kiln need a 32 A circuit, a 40 A circuit or three-phase, and is that possible from the existing consumer unit or distribution board?
• How far is the kiln position from the board? (Long cable runs cost more, so this can change where you put the kiln.)
• Can we have a local isolator by the kiln, and a separate RCD-protected circuit for the wheels with sockets above splash height?
• If we need a bigger supply or three-phase, who applies to the network operator, and what's the likely timescale?
• Is this notifiable work, and will we get an Electrical Installation Certificate?
• What will it cost, and when can it be finished? (We'd want the kiln circuit in at least four weeks before opening.)

Get at least two quotes, and make sure both are pricing the same thing.

Where we come in

We design and make equipment, and we sell kilns. We don't do electrical installation and we'd never pretend to. What we can do is make the electrician's job easier and the decision less of a guess. On a free planning call we'll sense-check your kiln choice against the supply you've got, suggest alternatives if the numbers don't fit, and give you a spec to pass on. The Studio Power Calculator produces a one-page spec sheet for exactly that conversation. If the room also needs extraction, read our guide to kiln ventilation and safety before the electrician visits, because fans need power too. And when you're budgeting for all of this, our studio cost guide shows where the electrical work sits alongside the equipment.

Setting up at home rather than opening to the public? Our home kiln buying guide is the better place to start.

Keep reading

• Kiln Ventilation & Safety: where the kiln goes, how the fumes get out.
• Finding & Fitting Out a Space: what to check before you sign the lease.
• How Much It Costs: equipment budgets at 4, 8 and 12 wheels.