HOW TO HIRE · ELECTRICAL

How to hire a generator installer in the UK
The checks, the questions and the paperwork.

A generator must connect through a proper changeover switch. The register check, the siting and fumes questions, and what to keep.

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THE 60-SECOND VERSION

Hiring a generator installer in five steps

  1. Decide what must stay onHeating, freezer, medical equipment, home office — the list sizes the generator.
  2. Check the registerIn England and Wales, look up whoever will do the generator connection on the Registered Competent Person Electrical register.
  3. Insist on a changeover switchNever a generator plugged into a socket to back-feed the house.
  4. Plan the sitingOutdoors, clear of doors and windows, on a proper base.
  5. Get the certificateFor the changeover and any new circuit, with test results.

BEFORE YOU BOOK

Check before you book

Registered Competent Person Electrical

In England and Wales, the generator connection is electrical installation work; a new circuit or a replacement consumer unit for it is notifiable. Where the generator connection is notifiable, an electrician on a government-authorised competent person scheme, such as NICEIC or NAPIT, self-certifies it under the Building Regulations; anyone else must notify building control before starting, and you pay for that inspection. Ask who insures the trader doing the generator connection and for how much; public liability is standard. The Consumer Rights Act 2015 covers the generator connection when the provider is a trader, and a contract made off-premises or online can usually be cancelled within 14 days under the Consumer Contracts Regulations 2013 — less what was done if you asked for an early start, and not at all for goods made to your specification.

Look up the business name on the register; it takes a minute and should come before the generator connection. Ask for proof of insurance for the generator connection; the trader and ID-checked badges are on the Locufy profile. electricalcompetentperson.co.uk →

Electrical Installation Certificate

When the generator connection is complete, the changeover arrangement and any new circuit are tested to BS 7671 and recorded on a certificate. Notifiable work such as the generator connection can bring a compliance certificate from the scheme, which gov.uk expects within 8 weeks in England and the Welsh Government within 30 days in Wales.

Ask for the certificate, with the test results filled in, on the day the generator connection is finished. gov.wales →

Carbon monoxide

A fuel generator gives off carbon monoxide. In Scotland any home with a carbon-fuelled appliance needs a carbon monoxide detector in that room, and in England landlords must fit alarms under the 2015 Regulations; a generator running near the house is a good reason for an alarm wherever you live.

Ask where the generator connection puts the exhaust, and fit a carbon monoxide alarm indoors. gov.scot →

Building warrant (Scotland) and Northern Ireland

Scotland has no competent person register for electricians: the generator connection must meet building standard 4.5, which means wiring to BS 7671, and some work, such as rewiring a flat, needs a building warrant that the owner applies for. For the generator connection in Northern Ireland, the building regulations contain no Part P-style notification scheme for domestic wiring.

For a Scottish home, ask the electrician whether the generator connection needs a building warrant and whether they are an approved certifier of construction. gov.scot →

VAT

Expect 20% VAT, the standard rate, on installing a standby generator: a business above the £90,000 registration threshold is required to charge it and to show it separately from the labour and materials.

Ask for the VAT number, and look for VAT as its own line on the generator quote. gov.uk →

“How will the generator connection switch over from the mains?”

A good answer: A changeover switch, manual or automatic, so the generator can never feed back into the network.

“What size of generator do my essential circuits need?”

A good answer: A load worked out from your list, not the biggest unit on offer.

“Will the consumer unit change for the generator connection?”

A good answer: A clear answer; separating essential circuits may mean a new board, which is notifiable in England and Wales.

“Where will the generator sit, and where do the fumes go?”

A good answer: Outdoors on a base, clear of doors, windows and vents.

“How is the fuel stored and topped up?”

A good answer: A safe arrangement for petrol, diesel or gas, explained.

“Which certificate will I get?”

A good answer: An Electrical Installation or Minor Works Certificate for the changeover and any new circuit.

Getting the quote right

  • Generator model and output, or labour only
  • Changeover switch type — manual or automatic
  • Consumer unit changes and new circuits
  • Base, enclosure and siting work
  • Who actually attends — the electrician wiring the changeover, employed or subcontracted — and the business's VAT number, with VAT at 20% shown as its own line
  • Certification included

Walk away if

  • Suggests a lead from the generator into a socket
  • No changeover switch
  • Sites the generator in a garage with the door shut
  • No certificate for the connection
  • Oversells a whole-house unit without a load calculation
LOW
£1,000
TYPICAL
£3,500
HIGH
£15,000

What a generator installer costs: £1,000–£15,000 per install

Generator installation is priced per install; a portable unit wired in through a changeover switch is the low end, and a fixed automatic standby generator with its own base and fuel supply costs far more. Generator Installation price guide →

Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.

KNOW WHAT TO LOOK FOR? NOW FIND ONE

Generator installers near you, with the badges that matter shown

ID checked, trader status and one score from every review — on the card, before you message anyone. Nearest first. No account needed to look.

Or post the job free and let them come to you.

  1. Assess the loadEssential circuits listed and the generator sized.
  2. SiteBase laid outdoors, clear of openings.
  3. Install the changeoverChangeover switch and any board changes fitted, with the supply isolated.
  4. TestThe installation tested to BS 7671 and a changeover run.
  5. Certify and trainCertificate handed over and you shown how to switch over safely.

Changeover switch
A switch that connects the house to either the mains or the generator, never both.
Automatic transfer switch
A changeover that starts the generator and switches over by itself.
Back-feed
Power flowing from a generator into the network, which is dangerous.
Essential circuits
The circuits chosen to stay on during a power cut.
Standby generator
A fixed generator that starts when the mains fails.
Carbon monoxide
The poisonous gas in generator exhaust.

AFTER

When the job is done

Keep the certificate and the manualThe electrical certificate and the generator's service schedule.
Practise a changeoverWith the installer there, switch to the generator and back.
Fit a carbon monoxide alarmIndoors, near where fumes could enter.
Leave the reviewOnly booked jobs can be reviewed on Locufy, so yours carries weight; if the generator connection falls short, use the make-it-right step first and the provider is asked to fix it before the review is published.

STEP 1Start with the electrician, in writingSend the electrician a short, dated account of the problem with the generator connection and the fix you want. Section 49 of the Consumer Rights Act 2015 implies reasonable care and skill into the contract, and section 54 gives you repeat performance or a price reduction when it is missing.
STEP 2Use Locufy's make-it-right stepRate the generator connection under four stars and you are asked whether to send it to the provider first; we follow it through. Then the review goes up.
STEP 3Unsafe or uncertified workWhere the generator connection needed self-certifying or notifying in England or Wales and neither happened, building control at the council is the place to go; if only the compliance certificate is missing, ask the electrician's scheme to follow it up. For a dispute about the generator connection with the trader, Trading Standards is reached through the Citizens Advice consumer helpline on 0808 223 1133 in England and Wales, Advice Direct Scotland on 0808 800 9060, or Consumerline on 0300 123 6262 in Northern Ireland.
STEP 4Money still in disputeIf the generator connection is still not settled, you can claim without a solicitor: the small claims track takes claims up to £10,000 in England and Wales, simple procedure up to £5,000 in Scotland, and the small claims court up to £5,000 in Northern Ireland.

Hiring a generator installer: questions people ask

Connecting a generator to the house wiring is electrical installation work; a new circuit or replacement consumer unit for it is notifiable in England and Wales.

An Electrical Installation or Minor Works Certificate for the changeover and any new circuit.

£1,000–£15,000 an installation, typically around £3,500. A portable generator with a changeover switch is the low end; a fixed standby unit costs far more. For the breakdown, see the Generator Installation price guide; put in your postcode above to see generator installers near you and what they charge.

No. Back-feeding through a socket is dangerous; a changeover switch is the safe connection.

Outdoors, on a base, away from doors, windows and vents because of the fumes.

It is a sensible precaution wherever a fuel generator runs near the home, and in Scotland the law requires one in any room with a carbon-fuelled appliance.

MORE GUIDES

More hiring guides in electrical

How to hire: Consumer Unit / Fuse Board UpgradeHow to hire: Battery Storage InstallationHow to hire: Solar PV InstallationHow to hire: Three-Phase InstallationHow to hire: Carbon Monoxide AlarmHow to hire: ElectricianHow to hire: Outbuilding Power SupplyHow to hire: Emergency ElectricianAll 701 hiring guides →

Generator installers near you

Generator installers in LondonGenerator installers in ManchesterGenerator installers in BirminghamGenerator installers in GlasgowGenerator installers in BelfastAll generator installers on Locufy →

Sources — checked October 2026

  1. gov.uk — Approved Document P: electrical safety in dwellings (England)
  2. Registered Competent Person Electrical register
  3. gov.uk — building work, replacements and repairs to your home (England)
  4. gov.wales — building regulations: electrics
  5. gov.scot — Building Standards Technical Handbook 2022 (domestic), standard 4.5 electrical safety
  6. gov.scot — fire and smoke alarms: the law
  7. Consumer Rights Act 2015, section 49 — reasonable care and skill
  8. Consumer Rights Act 2015, section 54 — what you can ask for when a service falls short
  9. Consumer Contracts Regulations 2013, regulation 30 — the 14-day cancellation period
  10. Consumer Contracts Regulations 2013, regulation 28 — contracts the cancellation right does not cover
  11. Consumer Contracts Regulations 2013, regulation 36 — services started within the cancellation period
  12. Civil Procedure Rules Part 26 — the small claims track limit (England and Wales)
  13. Scottish Courts and Tribunals — making a claim under simple procedure
  14. nidirect — the small claims process (Northern Ireland)
  15. Buildings and construction (VAT Notice 708) — 2.1 Construction services: work to an existing building is normally standard-rated
  16. GOV.UK — VAT rates
  17. GOV.UK — Register for VAT: when to register