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Commercial electrical services
Installations, testing, emergency lighting, fire alarms, data and security for offices, schools, care homes and industrial units, by our own engineers.
SEGplc is a commercial electrical contractor based in St Albans. We install, test and maintain the electrics in offices, schools, care homes, shops, industrial units, places of worship and mixed-use buildings across Hertfordshire, Bedfordshire, Buckinghamshire and London, with our own employed engineers and one point of contact.
Our commercial electrical services
| Service | What it covers | More detail |
|---|---|---|
| Installations and fit-outs | New circuits, office and shop fit-outs, kitchens, refurbishments | Electrical installations |
| Power distribution | Distribution boards, sub-mains, supply upgrades, three-phase | Mains and sub-mains |
| Testing and compliance | Fixed wire testing (EICR), PAT testing, remedial works | Fixed wire testing |
| Emergency lighting | Design, installation, monthly and annual testing, certificates | Emergency lighting testing |
| Fire alarms | BS 5839-1 systems, conventional and addressable, servicing | Fire alarm installation |
| Lighting | LED upgrades, external and car park lighting, controls | LED upgrade case study |
| Data and Wi-Fi | Cat6 and fibre cabling, racks, access points, tested and certified | Data cabling |
| Security | CCTV, access control and door entry | CCTV and access control |
| EV charging | Workplace and depot charge points | EV chargers |
| Reactive and call-outs | Faults, failures and urgent repairs | Emergency call-outs |
Recent commercial electrical work
Real jobs from our records. We don’t name our clients.
- Offices in St James’s, London: access control on ten doors, maglock replacements, a meeting-room and kitchen refit, and AV installation.
- City of London office floor: 100 data outlets terminated and tested.
- A secondary school in east Hertfordshire: external lighting replaced with LED, from lamp-post heads to emergency exit bulkheads.
- Care and nursing homes: EV charge points commissioned, and data cabling for a care home.
- A business depot in Baldock: commercial EV charging installed in one day after a survey visit.
- Places of worship in St Albans: fire and CO detection, a new parish office with power and data, Wi-Fi, and an EICR with an emergency lighting test.
- Industrial units in Dunstable and Stevenage: fault investigation and electrical works.
How we work
- Survey. We visit, look at the installation and agree what you need.
- Quote and programme. A clear written scope, price and programme, phased around your business.
- RAMS. Risk assessments and method statements before we start.
- The work. Done by our own engineers, with shutdowns agreed in advance.
- Certificates and handover. Test results and certificates at the end, and a 12-month workmanship guarantee.
We are NICEIC approved and ECA members, and hold CHAS, SafeContractor and Constructionline, so your facilities team or main contractor doesn’t have to vet us from scratch. Our engineers are employed by SEG, not a chain of subcontractors.
Keeping the building compliant
As the person responsible for a building, you need to show the electrics are safe. These are the recommended maximum intervals we work to:
| What | How often | Standard |
|---|---|---|
| Fixed wiring inspection (EICR), offices and shops | At least every 5 years | IET Guidance Note 3 |
| Fixed wiring inspection, industrial units | At least every 3 years | IET Guidance Note 3 |
| Fixed wiring inspection, schools and care homes | At least every 5 years | IET Guidance Note 3 |
| Emergency lighting | Monthly function test; full-duration test every year | BS 5266-1 |
| Fire alarm system | Weekly call-point test by you; service at least every 6 months | BS 5839-1 |
We can put all of it on one schedule: see commercial electrical maintenance.
Commercial electrical services: questions we’re asked
What commercial electrical services do you offer?
Installations and fit-outs, distribution boards and sub-mains, lighting and emergency lighting, fire alarms, fixed wire testing (EICRs), PAT testing, data cabling and Wi-Fi, CCTV and access control, EV charging, containment, and reactive call-outs, all from one contractor.
Do you work in occupied buildings?
Yes. Most of our commercial work is in buildings that stay open: offices, schools, care homes, shops and places of worship. We plan noisy or disruptive work and shutdowns around you, and agree access, permits and building rules before we start.
What paperwork do we get?
Risk assessments and method statements (RAMS) before we start; electrical installation or minor works certificates when we finish; EICRs for inspections; test results for data cabling and emergency lighting; and building regulations notification where the work needs it.
Can you look after several sites?
Yes. Multi-site clients get one point of contact, one schedule of testing dates and one set of records for every site.
How quickly can you get to us?
Our phones are answered 7am to 10pm, seven days a week, and planned work can be booked out of hours. For emergencies in St Albans and the towns around it we aim to be on site within the hour, Monday to Friday, 8am to 5pm; see emergency call-outs for the areas covered.
Do you only work in Hertfordshire?
No. Our head office is in St Albans and our engineers work across Hertfordshire, Bedfordshire, Buckinghamshire and London.
Written by SEGplc. Last updated 19 October 2026.
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