First and second fix: when does the electrician need to be on site?

What does the electrician need on site before first fix can start?

A decided layout. Not a date, not a deposit, a decision. It is the commonest reason an electrician arrives on a site that is not ready.

• A marked up plan, or twenty minutes walking round with whoever is deciding. Socket positions, switch drops, the lighting layout, where the board goes and where the incoming supply lands. It does not have to be a beautiful drawing. It has to be decided.
• Everything with a cable in it that is not obviously electrical. Heating controls, an extractor, underfloor heating, data, an alarm, an EV charge point, a feed to a garage or a garden room. These get left off and come back as a chase in a finished wall.
• Who is supplying the accessories and light fittings. A fitting nobody has bought is a second fix that does not finish, and it is the commonest reason a job stays open.
• The building itself. Weathertight, studs and joists open, safe access, power on site.

Worth saying plainly to a client: a builder who rings for a first fix date before the kitchen and the lighting are signed off is buying a date that will move. The layout is the gate.

When exactly does first fix go in on a builder’s programme?

After the structure is weathertight and before the plasterer, and that window is usually shorter than people plan for.

• New build or extension. Shell up, roof and windows in, before insulation, boarding and plaster. Our extension electrics article covers what the work itself involves.
• Refurbishment. After the strip out, once walls are back to brick or the studs are open.
• Alongside the plumber. First fix electrics runs with or just behind first fix plumbing, because pipework bends in fewer places than cable does.
• Before the screed. Anything under a solid floor, an island feed, underfloor heating, a floor box, has to be in before the screed. Afterwards it is not a change, it is a breakout.

Done, at first fix, means cables run and terminated into back boxes, containment in, the board position set, and everything labelled and safe. Then the plasterer.

One programme item people forget: if the project runs through a building control application, building control will normally want to see the work before it is covered up. That inspection sits on the programme like any other trade.

When does second fix happen, and what holds it up?

After the decorating, not before it. Accessories, light fittings, the consumer unit, the final connections, then testing and certification, in that order.

• Fittings not on site. The biggest single cause. One backordered pendant keeps a job open for a fortnight.
• A decorator who is not finished. Fitting accessories into a room that is painted afterwards means marked accessories or a return visit.
• A kitchen that is not in. Appliance connections and the isolation above the worktop cannot be done around a stack of flat pack. See our kitchen refit article.
• Flooring not down, where a floor box or an underfloor feed comes up.

Testing is not a formality and it is not an afternoon. It is where a cable somebody screwed through gets found, which on a bad day is behind a painted wall. Putting it on the programme as its own item is what keeps handover dates honest.

Who notifies building control, the builder or the electrician?

The electrician, provided they are registered on a competent person scheme. A general builder cannot self certify electrical work unless they hold that registration themselves.

The notifiable list in England is short: a new circuit, a replacement consumer unit, and work on circuits in a special location, meaning a room containing a bath or a shower. Wales kept the wider rules. If the person doing the work is not registered, it has to go to building control in advance and be inspected instead, which is slower and costs more.

Certification is separate from notification and applies either way. New circuits get an Electrical Installation Certificate, alterations get a Minor Electrical Installation Works Certificate, and both are what a homeowner needs at sale. Over the top of all of it, CDM 2015 puts duties on the client, the principal contractor and every contractor to plan, manage and coordinate the work.

Agree at the start, in writing, who issues what. The gap between what the builder assumed and what the electrician assumed does not surface on site. It surfaces at handover, or three years later at a sale. Our first and second fix page sets out how we handle it.

What actually makes an electrician miss a programme date?

Usually not the electrician, and knowing the real order of causes lets a builder plan round most of them.

• The layout was never decided. First, for a reason.
• The trade in front slipped. A first fix booked for the Monday after a plasterer running a week late was never a real date.
• Lead times. A specific board, a specialist fitting, anything three phase. Ordering when the programme needs it is ordering too late.
• The network operator. A new connection or a supply upgrade runs to the DNO’s timetable, not yours, and it is measured in months.
• Somebody damaged the first fix. Found at testing, by which point the wall is painted.

So here is the blunt bit, and it is not what most contractors put on a website. Any electrician can promise you a date in March for a job in June, and the promise is worth nothing. What is worth having is one who rings the moment a date is at risk, early enough that you can still move the plasterer and the decorator round it. A slipped date you knew about a fortnight ago is a scheduling problem. The same date sprung on you on the morning costs everybody a week.

What changes the price of a first and second fix package?

We price from drawings and a point schedule rather than a description, because the things that move the number are the things a description leaves out.

• The number of points: sockets, switches, light points, data and outlets. Not the number of bedrooms.
• The construction. Timber stud is quicker than chasing blockwork, and a solid floor changes every route that crosses it.
• The consumer unit: whether it stays, takes a spare way, gains a small second board, or goes.
• Anything specialist in the package: three phase, an EV charge point, underfloor heating, solar or battery storage.
• How many visits the programme genuinely needs, and who supplies the fittings.

And the one worth saying out loud. First fix is the cheapest part to under-price and the most expensive part to get wrong, because everything skimped is behind plaster by the time anyone notices. A first fix price well under the others is usually fewer points, less containment and no allowance for the awkward runs, and it comes back as variations at second fix. Compare the point schedules, not the totals. Send drawings and a programme and we will price the actual job on our quote page.

Questions we get asked about this