How to write a quote for a full rewire (UK electrician walkthrough)

A mate of mine quoted a 3-bed semi rewire last spring at a round £4,000, said over the phone in the customer's hallway. He hadn't lifted a floorboard yet. Once the walls were open it turned out to be lath and plaster, the lighting circuits had no earth, and the artex ceilings needed testing for asbestos before he could touch them. The plasterer's making-good bill alone was £600 he hadn't allowed for. He finished the job about £900 down on where he should have been, and the customer still thought they'd got a fair deal.

A rewire is one of the best earners a small electrical firm has. It's also one of the easiest to underprice, because the number is big enough to feel generous while still being too low.

This guide is how to quote one properly. What a full rewire actually includes, how to price it by work package instead of a figure off the top of your head, a full worked example for a 3-bed semi that lands at £4,673 before VAT, and the two lines on the quote that stop the unknowns eating your margin.

What a full rewire actually includes

Before you can put a number on it, the scope has to be clear in your own head, because the customer's idea of "a rewire" and yours rarely match. A full rewire means stripping out every cable and accessory and replacing the lot. New cabling to all circuits, new sockets and switches, a new consumer unit, the testing, and the certificate at the end. Then someone has to make good the walls you've chased into.

The job splits naturally into five packages, and quoting it package by package is what stops things falling through the cracks.

1. Strip out and first fix

Lifting carpets and floorboards, getting the old cable out, chasing the walls, running the new twin and earth to every point, dropping in back boxes, and running the circuits back to where the board will go. This is the dirty, heavy half of the job and the bulk of the labour. On a 3-bed it's usually four to six days.

2. Consumer unit and second fix

Fitting the new metal consumer unit to the current edition of BS 7671, terminating every circuit, and fitting all the accessories: sockets, switches, light fittings, the cooker outlet, the shower, the smoke and heat alarms. Second fix is where the house starts looking finished again.

3. Testing, inspection and certification

Full testing of the installation, the Electrical Installation Certificate under BS 7671, and the Building Regulations notification. This is not optional and it's not a freebie. It's a day's work plus the scheme fee, and it has to be in the price.

4. Materials

Cable, the consumer unit, accessories, back boxes, alarms, and all the sundries. Priced at trade cost with a sensible markup, because you're sourcing it, collecting it, storing it, and standing behind it.

5. Making good

Once you've chased a dozen channels into the plaster, someone has to fill them. Either you price a plasterer in, or you make it a provisional sum and a clear exclusion. What you must not do is leave it out and hope. Making good is the line that quietly sinks underpriced rewires.

Price by work package, not a number in the hallway

The figure you say out loud in the customer's hall becomes the price, whether you've seen behind the walls or not. So don't say one. Tell the customer you'll have a proper itemised quote over to them within a day or two, then build it up from the packages above.

Work in days for the labour. Decide your day rate, count the days each package realistically takes, and multiply. Add the materials at cost plus markup. Add the certification and the notification fee. Add the making good. Total it, then decide whether you're showing VAT or not. One fixed figure, itemised so the customer can see what they're paying for, but a single number at the bottom they can plan around.

This matters more than it sounds. A customer reading two quotes side by side almost always goes with the one that looks like the firm has its act together, even when it isn't the cheapest. A clear, itemised quote that arrives the next day beats a lower number scrawled on the back of a wholesaler's docket that turns up the following week.

Worked example: a 3-bed semi, line by line

Here's a full rewire priced the way it should be. The property is a 1960s 3-bed semi, two reception rooms, kitchen, bathroom, three bedrooms, landing and hall. Around ten circuits. The customers are living in it, so it's worked room by room, which adds a bit of labour. Labour is priced at a £280 day rate.

Labour

• Strip out and first fix, 5 days: £1,400
• Consumer unit and second fix, 3 days: £840
• Testing, inspection and certification, 1 day: £280

Labour subtotal: £2,520

Materials (trade cost, then markup)

• Cable, earthing and bonding: £420
• Metal consumer unit, RCBOs and surge protection to BS 7671: £220
• Accessories: sockets, switches and back boxes, around 55 points: £390
• Mains-interlinked smoke and heat alarms, 4 units: £180
• Sundries: clips, grommets, fire-rated downlights, conduit: £210

Materials at cost: £1,420. Markup at 15%: £213. Materials subtotal: £1,633

Notifiable work and making good

• Part P notification through your competent person scheme: £70
• Provisional sum, plasterer making good the chased walls: £450

The total

£2,520 labour, plus £1,633 materials, plus £70 notification, plus £450 making good, comes to £4,673 before VAT. If you're VAT registered you add 20%, which is £934.60, for a total of £5,607.60. If you're under the £90,000 threshold and not registered, the price stays at £4,673, but remember you can't reclaim the VAT on your materials, so that VAT is sitting inside your costs as a real expense.

The two lines that protect your margin

Two things wreck rewire quotes: the customer changes their mind on the accessories, and the building hides a problem. A PC sum and a provisional sum cover both, and they're the difference between a profitable rewire and a charitable one.

The PC sum, for what they haven't chosen

A PC sum, short for prime cost, is an allowance for an item the customer hasn't picked yet. On a rewire it's usually the accessories. You quote on standard white moulded sockets and switches, then put a line that says "accessories allowed at standard white moulded; brushed steel, screwless, or USB sockets to be adjusted on the final invoice".

Say the job has 55 points and the customer decides halfway through that they want brushed steel screwless throughout. Standard white is roughly £2 a point. Brushed steel screwless is closer to £9. That's £7 a point across 55 points, so £385 added to the final bill, plus your markup. Without the PC sum line, that £385 comes straight out of your pocket, because as far as the customer remembers, the quote said "all accessories included".

The provisional sum, for what you can't see

A provisional sum is an allowance for work you can't fully price until you open up. Older houses hide all sorts. Lath and plaster walls that crumble when you chase them and take three times as long. Lighting circuits with no earth, so the customer wants new metal fittings and you've nowhere to land the earth. Asbestos in artex ceilings or textured coatings that has to be tested and sometimes removed by a licensed contractor before you can drill into it. A meter tails and main bonding setup that the DNO needs to look at.

You put a line like "provisional sum: £450 for making good, adjusted to actual on completion" and, where it applies, "provisional sum: £250 for additional works if lath and plaster or absent earths are found, by agreement before proceeding". If the walls are sound and modern, the customer doesn't pay the extra. If they're not, you're covered, and there's no awkward conversation halfway through the job about money the customer feels ambushed by.

Notifiable work, certs, and the bits customers forget

A full rewire is notifiable work under Part P of the Building Regulations in England and Wales. There's no way round it, and it has to be in the price.

If you're registered with a competent person scheme (NICEIC, NAPIT, ELECSA, or Stroma), you self-certify the work and the scheme notifies Building Control on your behalf, usually for a small per-notification fee. If you're not registered, you have to notify your local authority Building Control before you start, and they'll either inspect or appoint someone to, which costs more and slows the job down. Scotland works to its own building standards system and Northern Ireland to its own regulations, so check the rules for where you're working. You can confirm the current position on gov.uk.

On completion the customer gets an Electrical Installation Certificate (EIC) under BS 7671, plus the Building Regulations compliance certificate from your scheme. Tell them to keep both somewhere safe. They'll be asked for them when the house is sold, remortgaged, or let out, and "the sparky never gave me one" is a problem that lands back on you years later.

Two more things that belong in the quote and that customers routinely forget. Alarms: mains-interlinked smoke and heat alarms are standard on a rewire now, and in Scotland interlinked alarms are a legal requirement in every home. Deposit and stage payments: a rewire ties up real money in materials before you've earned a penny. The consumer unit, cable and accessories in the example above are over £1,400 at cost. Take a deposit that covers what you order in, a stage payment at first-fix sign-off, and the balance on completion. There's no legal cap on a deposit, but a fair one covers your materials and sits at or under about a quarter of the job. The deposit guide covers the cancellation rules that catch trades out.

What NOT to do (the 5 mistakes that cost you)

1. Don't quote a round number in the hallway. The figure you say out loud is the price, and you haven't seen behind a single wall yet. Tell them you'll send a proper itemised quote within a day or two, then do exactly that.
2. Don't leave making good out. Chasing a dozen channels into plaster creates a real bill to fill them. Price the plasterer in or make it a clear provisional sum. Leaving it out is the single most common way a rewire goes from profit to loss.
3. Don't quote accessories open-ended. No PC sum means every brushed-steel upgrade the customer fancies comes out of your margin. Allow a standard rate, adjust on the final invoice.
4. Don't forget the certs and notification. The EIC and the Part P notification are a day of work plus a fee. Skip them in the quote and you either eat the cost or, worse, skip the notification and leave yourself exposed.
5. Don't price for an empty house when it's a lived-in one. Working room by room around a family, lifting and relaying carpets, moving furniture, and tidying every evening adds real days. Price the house in front of you, not the easy version.

The habit that wins the job

Get the quote to the customer within a day or two, itemised and tidy, while they're still picturing the finished house with the new sockets where they actually want them. A clear, professional quote that lands quickly beats a cheaper one that turns up a week later looking like an afterthought. Customers reading two quotes side by side go with the firm that looks organised, even when it isn't the lowest number, because a rewire is disruptive and they're really buying the confidence that you'll do it properly and clear off when you said you would.

That's the bit most firms leave on the table. The wiring is rarely the hard part. It's the gap between walking the job and getting a proper quote out. TradeStash lets you build a packaged rewire quote from the van, drop in the PC sums and the provisional sums, and send it before you've left the customer's drive. Quote fast, quote properly, and you win more of the jobs worth winning.