What to Expect from a Qualified Electrician

Rewiring a kitchen, adding a garden office supply or swapping an old fuse box for a modern consumer unit are jobs where the difference between a competent electrician and a cheaper alternative becomes painfully obvious — usually at 11pm when the RCD won't reset. A qualified electrician does far more than pull cables and connect them up. The testing, certification and advice that come with the work are what keep your home safe and your paperwork clean when you come to sell or insure it. Here's what a proper job should look like from start to finish.

What "Qualified" Should Actually Mean

Ask a few direct questions before anyone lifts a screwdriver. A competent domestic electrician in the UK will typically hold a Level 3 qualification in electrical installation, plus the current edition of the wiring regulations — BS 7671, usually referred to as the 18th Edition. Many have completed an apprenticeship with an AM2 assessment at the end.

For notifiable domestic work, they should be registered with a government-approved competent person scheme, which allows them to self-certify that the work complies with Part P of the Building Regulations in England and Wales. Also worth checking:

• Public liability insurance — ask for the certificate, not just a verbal yes.
• A valid scheme registration card or number you can verify yourself.
• Test instruments with a current calibration certificate. Uncalibrated gear produces meaningless readings.

If a quote arrives with no mention of certificates or testing, treat that as a red flag rather than a saving.

The Testing Process, Explained Plainly

Testing happens in two stages. Dead tests are carried out with the supply isolated: continuity of protective conductors, ring final circuit continuity, polarity, and insulation resistance measured at 500V DC, which should come out at 1 megohm or higher. These catch damaged cables, borrowed neutrals and loose earths that would otherwise sit unnoticed behind plasterboard for years.

Live tests come next. Your electrician will measure earth fault loop impedance (Zs) to confirm the protective device will disconnect fast enough under fault conditions, check the external earth loop impedance (Ze) at the origin, and verify that every RCD trips within the required time — no more than 300 milliseconds at its rated residual operating current, and 40 milliseconds at five times that. Socket outlets get a polarity and functional check, and the whole installation gets a visual once-over.

A good electrician will talk you through the results in plain English rather than simply handing over a sheet of numbers.

The Certificates You Should Be Given

Different jobs generate different documents, and you are entitled to a copy of each.

• Electrical Installation Certificate (EIC) — for new circuits, a consumer unit replacement or a full rewire. It comes with a Schedule of Inspections and a Schedule of Test Results listing every circuit and its measured readings.
• Minor Electrical Installation Works Certificate — for small alterations such as adding a spur or extending a circuit. Less comprehensive, but still essential.
• Building Regulations compliance certificate — issued through their competent person scheme or, where relevant, your local authority building control, confirming the work is notifiable and has been notified.
• Electrical Installation Condition Report (EICR) — if you've asked for an inspection rather than new work. Faults are graded C1 (danger present), C2 (potentially dangerous), C3 (improvement recommended) or FI (further investigation required).

Keep these with your property documents. Solicitors, buyers and insurers ask for them.

Advice on Load Capacity and Headroom

One of the most valuable things a qualified electrician offers is honest advice about capacity. Before adding an electric shower, an EV charger or a heat pump, they should carry out a load calculation using diversity allowances rather than simply assuming the supply will cope. They'll check the rating of your cut-out fuse — commonly 60A, 80A or 100A — and tell you if a supply upgrade with your distributor is likely to be needed.

They should also be upfront about consumer unit capacity. If your new board is fitted with no spare ways, every future addition becomes an expensive reconfiguration. Ask directly: how much headroom does this leave me, and what would I need if I added an electric vehicle charger in two years? A vague answer is not good enough.

Safety Checks Before They Pack Up

Certain checks should be routine, not optional. Terminal screws inside the consumer unit should be tightened to the manufacturer's specified torque — loose connections are a leading cause of overheating. Main protective bonding conductors to gas and water services should be in place and within 600mm of where the services enter the property, where practical.

Every RCD should be tested at the device itself, the consumer unit should be clearly labelled with an accurate circuit chart, and warning notices such as "both sides of this consumer unit remain live when the main switch is off" should be fitted. Any supplementary bonding in a bathroom, if required, should be verified. Finally, they should leave the installation clean and demonstrate that everything works before they go.

Questions Worth Asking Before You Pay

A few minutes of conversation at handover protects you for years.

• Which certificates will I receive, and when will they arrive?
• Is this work notifiable, and who is notifying building control?
• What are my measured Zs and RCD trip times, and are they within limits?
• Can I have a copy of the full Schedule of Test Results, not just the summary page?
• What guarantee do you provide on labour, and who do I contact if a breaker trips next month?

Pay the final balance only once the certificates are in hand. Any electrician worth employing will expect that question and answer it comfortably.