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.
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
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
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
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.
Proven on site
Electrical installation delivered inside live buildings
Two ComGas projects where the electrical package was installed alongside mechanical works on the same programme.
What customers say about our electrical installation work.
Genuine reviews from ComGas customers submitted through Google.
Posted on Google
Nick
3 September 2026
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Matt from ComGas Services UK Ltd was very professional, polite, friendly and quick installing a new shower in my bath (and at a better height for me) and a much easier press-in plug for my sink! He left the place spotless. This is the kind of service and installation people dream about - a 5 star service (see photos).
Posted on Google
Laura Peters
17 August 2026
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I have used Comgas twice and both times have been very happy with the service. Very friendly and honest. The most recent time, the job turned out to be a lot bigger than they initially thought but it was no issue and Paul stayed the extra time to make sure the job was done properly! He was really tidy, took a lot of care with the work that was done and took the time to explain what he was doing and why. Pleased to have found a reliable heating company!
Posted on Google
James Ross
8 August 2026
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I had an issue with my boiler and Matt came out to have a look the same day and managed to fix it. Great, professional service. Highly recommend.
Posted on Google
Ian Chevalier
11 June 2026
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First time we've used this company and it won't be the last. Very professional and efficient in everything they do and Matt was excellent in his knowledge and efficiency when dealing with our gas and plumbing problems.
Posted on Google
Karen Flackett
20 May 2026
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Excellent service. Matt came & fitted 2 taps & waste pipes he was polite & friendly & carried out the work efficiently & in a timely manner.
Posted on Google
Paul Norris
30 April 2026
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Fantastic experience from the chaps at ComGas! Special thanks to Matt who removed an old boiler and replaced with a new energy efficient to satisfy the demands of a five bed house with a few bathrooms/baths and showers. The ComGas admin team and Lee were fantastic too on the booking and administration side of things!
Posted on Google
Julie Galvin
21 April 2026
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Here at St Joseph's we have worked with Comgas for a number of years. They have completed big projects and undertake regular maintenance for our school. They price fairly, and their work is completed to a very high standard. All the engineers carry a DBS which makes life so much easier when trying to book an engineer visit.
On the rare occasion that we have an emergency I can trust that Lee will get one of his engineers to respond quickly and efficiently.
Nothing is too much trouble and no job is too small.
Posted on Google
Chesca Haley
16 April 2026
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Lee and the team are amazing! So helpful, so knowledgeable and really look after their customers. Highly recommend.
Posted on Google
Sarah Rogers
6 April 2026
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Absolutely amazing service, always a thorough job and very knowledgable. Really nice guys too. Lee has sorted numerous issues at work and around our house. We have recommended to friends and family who are also very happy
Posted on Google
Alison Molan
25 March 2026
Trustindex verifies that the original source of the review is Google.
Lovely engineers, Matt and Jack, were a pleasure to have in the house. Thorough, knowledgeable, tidy and polite. Would highly recommend.
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.
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.
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.