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ComGas Services UK Ltd
Commercial electrical installation and rewiring work in progress
Commercial Electrical Installation

Commercial Electrical Installation

ComGas designs and installs commercial electrical systems for new build, refurbishment and fit-out projects — containment, distribution, power and lighting — for schools, care settings, offices and industrial buildings across Surrey and surrounding counties.

  • New build & refurbishment electrical
  • Sequenced with mechanical works
  • BS 7671 / 18th Edition certified
  • Occupied-building phasing considered
Electrical installation sized to how the building is actually used

The right electrical installation is set by how a building is used, not by its floor area.

A commercial electrical installation covers the containment, distribution, power and lighting that a building needs from first fix through to certification — whether that is a new build shell, a full refurbishment, or a tenant fit-out within an existing structure. The load profile behind that installation varies enormously: a school has different peak demand and switching patterns to a care home running assisted equipment around the clock, and an industrial unit with three-phase machinery is a different design problem again. Treating any of these as a generic specification tends to leave capacity or resilience short of what the building actually needs.

Getting the design wrong at this stage is expensive to correct later. Undersized distribution, containment routed without regard for future maintenance access, or power and lighting circuits designed around an assumed rather than confirmed load, all surface as problems once the building is occupied — at which point remedial work means reopening finished ceilings, walls and floors. A distribution board sized for today's tenant with no spare capacity for tomorrow's fit-out is a common example of a decision that looks economical at handover and expensive within a few years.

ComGas designs and installs commercial electrical systems for new build, refurbishment and fit-out projects across Surrey, Hampshire and Berkshire, working to BS 7671 / 18th Edition and issuing certification on completion. Because ComGas also delivers the mechanical services on many of the same projects, the electrical installation is sequenced against plant, pipework and heating works rather than being designed and installed in isolation.

ComGas Services UK Ltd
Commercial electrical installation from Farnham, Surrey.

Commercial electrical services

We design and install electrical systems matched to how the building will actually operate.

Containment, distribution, power and lighting installed and certified to BS 7671 / 18th Edition.

New Build & Extensions

Electrical design and installation for new commercial buildings and extensions, from shell and core through to final fix.

  • First-fix containment and distribution planned from the design stage
  • Power and lighting sized to the confirmed building use
  • Coordinated with the mechanical and gas installation programme
  • Certification issued on completion for handover
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Refurbishment & Rewires

Full or partial rewiring of existing commercial buildings where the electrical installation has reached the end of its service life or no longer matches occupancy.

  • Existing installation surveyed and load reassessed
  • Partial or full rewire scoped against actual condition
  • Distribution upgraded where capacity is no longer adequate
  • Work sequenced around an occupied or trading building
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Fit-Out & Tenant Works

Electrical installation for tenant fit-out and Cat A/Cat B works within an existing shell, coordinated with the wider fit-out programme.

  • Power and lighting designed around the tenant's confirmed layout
  • Containment and distribution coordinated with other fit-out trades
  • Spare capacity considered for future tenant change
  • Certification provided to support landlord and insurer requirements
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Phased Replacement in Occupied Buildings

Electrical installation replaced in stages across a live school, care setting or workplace, rather than as a single shutdown.

  • Isolation and switch-off windows planned around building operation
  • Phasing sequenced by zone, floor or department
  • Continuity of supply maintained to critical areas throughout
  • Progress and any findings reported at each phase
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How we approach a commercial electrical installation

Survey and assess the load, design in coordination, install containment and distribution first, then power, lighting and certification.

Before any installation begins, we survey the building and assess the load it actually needs to carry — accounting for how it operates, the equipment it houses, and any planned future use rather than only its current occupancy. Where the electrical installation runs alongside mechanical or gas works, which is common on ComGas projects, the two designs are coordinated so containment routes, plant room layouts and switch-off windows are agreed once rather than adjusted mid-installation.

Installation follows a fixed sequence: containment and distribution are installed first, since they set the constraints for everything that follows, then power and lighting circuits are fitted out to the confirmed design. Testing and certification are carried out before handover, with results and any relevant findings explained clearly so the client understands exactly what has been installed and confirmed.

  • Load assessed against actual building use, not assumed occupancy
  • Design coordinated with any parallel mechanical or gas works
  • Containment and distribution installed before power and lighting
  • Power and lighting circuits fitted to the confirmed design
  • Full testing and certification carried out before handover
  • Findings and certification explained clearly at completion
What we consider before any commercial electrical installation

Occupied buildings, phasing and coordination with other trades all shape the specification.

Most commercial electrical installation work happens in buildings that cannot simply close for the duration — schools run to term dates, care settings operate around the clock, and offices and industrial units need continuity for at least part of their operation. We plan isolation and switch-off windows around the building's actual pattern of use, phase work by zone or floor where a full shutdown is not practical, and coordinate builders' work and access with the other trades on site so the electrical programme does not collide with mechanical, gas or fit-out works running in parallel.

  • Isolation and switch-off windows agreed around building operation
  • Phasing planned by zone, floor or department where needed
  • Builders' work and access coordinated with other trades
  • Coordination with any parallel mechanical or gas installation
  • Spare distribution capacity considered for future change
  • Certification and documentation confirmed before handover
Discuss Your Electrical Installation Requirement

Every electrical installation is scoped to the specific building and how it operates, not applied as a standard specification regardless of the project. At Lowther Primary School in Barnes, electrical upgrades and zonal controls were delivered as part of wider de-carbonisation works for Richmond & Wandsworth Council. At Loseley Fields Primary School, electrical installation was delivered alongside mechanical and plant room works on the same programme.

Customer feedback

What customers say about our electrical installation work.

Genuine reviews from ComGas customers submitted through Google.

Commercial electrical installation FAQs

Questions about commercial electrical installation and rewiring

Common questions about scope, certification and how this service relates to our other electrical work.

Talk to the electrical installation team
Is this the same as your electrical maintenance service?

No. This page covers project work — new installation, rewiring and fit-out. Ongoing inspection, testing and reactive repair of an existing installation sits within our electrical maintenance service, which is a separate, ongoing arrangement rather than a one-off project.

We just need a distribution board replaced — is that this service?

A standalone distribution board replacement, without wider rewiring or fit-out work, is its own scope and is covered on our distribution boards page. This page covers full commercial electrical installation projects, of which a distribution board is one component.

Do you carry out domestic electrical installation as well?

Domestic and residential electrical work sits within our residential electrical section rather than here. This page is specifically for commercial buildings — schools, care settings, offices and industrial units.

Can electrical installation be coordinated with mechanical or heating works?

Yes, and on many ComGas projects it is. Because we deliver mechanical services and commercial heating works as well as electrical installation, we sequence containment, plant room layouts and switch-off windows across both disciplines rather than treating them as separate programmes.

How do you handle electrical installation in a building that cannot fully shut down?

We phase the work by zone, floor or department and agree isolation and switch-off windows around the building's actual operating pattern. This is standard practice for schools, care settings and workplaces that need to remain functional, at least in part, throughout the installation.

What certification do we get at the end of an installation?

All installation work is carried out to BS 7671 / 18th Edition and certified on completion, with documentation provided to support handover, landlord requirements or insurance where relevant.

Start a conversation

Planning a new installation, refurbishment or fit-out?

Tell us about the building, the works planned and any access or timescale constraints. We can advise on the right approach and coordinate with any mechanical works already underway.

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Discuss your commercial electrical installation requirements

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