Why rewire commercial premises?
A commercial rewire is usually driven by one or more of the following:
Safety
Old, damaged or overloaded wiring, tired distribution boards and missing RCD protection are the common causes of electrical fires and shocks at work. If the installation was not designed for the way the building is used today, it is carrying risk you cannot see.
Compliance
The Electricity at Work Regulations 1989 require the installation to be maintained in a safe condition, and BS 7671 sets the standard it is measured against. Most commercial premises need an Electrical Installation Condition Report (EICR) every five years, or more often for higher-risk uses. Repeated unsatisfactory reports usually mean a rewire is the sensible answer.
Capacity and reliability
Businesses use far more electricity than the buildings were wired for. A rewire gives you the circuits, the board space and the supply arrangement to run what you have now and what you plan to add, without nuisance tripping.
Energy efficiency
A rewire is the moment to move to LED lighting, sensible controls and modern equipment, which lowers the running costs of the building.
Insurance and liability
Insurers increasingly ask for a satisfactory EICR and can decline a claim if the installation is known to be dangerous or has not been maintained. As the employer or the person in control of the premises, you are responsible for the safety of everyone who uses it.
Selling or letting
A rewired, certificated building is easier to let, easier to sell and avoids disputes over dilapidations at the end of a lease.
What should I look for when choosing a contractor for a commercial rewire?
Qualifications and accreditations
Choose a company registered with a competent person scheme such as NAPIT or NICEIC and listed on electricalcompetentperson.co.uk. That shows they are assessed regularly and can certify their own work.
Commercial experience
Commercial rewires involve three-phase supplies, larger distribution boards, containment, emergency lighting and working around a live business. Ask what similar premises they have done.
Reviews and reputation
Check Google, Checkatrade and Facebook. Look for comments about turning up when promised, keeping the site tidy and communicating clearly, not just the star rating.
Insurance
Ask for proof of public liability, employers' liability and professional indemnity insurance.
Certification and warranties
You should receive an Electrical Installation Certificate with the schedule of test results and updated board schedules on completion. Our workmanship is guaranteed for 12 months and materials carry the manufacturer's warranty.
The quote
Get an itemised written quotation with a clear specification and any exclusions listed. Be wary of a price that is far below the others: it usually means cheaper materials, missing certification or corners cut somewhere you cannot see.
Yorkshire Electricians Ltd meets all of the above, and we are happy to show you the paperwork.
How long does a commercial rewire take?
It depends on the size of the premises, the specification, how much of the existing installation can stay, and whether we are working around your trading hours. A small shop or office unit is typically a few days; a larger office, workshop or warehouse can run to several weeks.
We agree a programme with you before we start, including any out-of-hours work and the order in which areas are done, so you know exactly when each part of the building will be affected.
Do we need an EICR before deciding on a rewire?
Often, yes. An Electrical Installation Condition Report is a thorough inspection and test of the whole installation. It tells you what is actually there, what is dangerous now (C1), what needs fixing urgently (C2) and what needs further investigation (FI). For a building with a long history of alterations it is the only reliable way to decide between a rewire and a targeted upgrade.
Sometimes a visual inspection is enough: an obviously aged installation, an old fuse board with no RCD protection, damaged cabling or repeated tripping all point the same way. Either way, we will tell you plainly what we recommend and why.
Can we stay open during the rewire?
In most cases, yes. We plan the work in phases so that only one area is out of action at a time, use temporary supplies where needed, and carry out the disruptive parts out of hours or at weekends. Some parts of the job, such as changing the main distribution board, do need the power off for a period, and we agree that with you in advance.
For a heavily occupied site the fastest and cheapest option is sometimes a short planned closure. We will give you both options with honest timescales so you can decide.
Do you do three-phase, and can you upgrade our supply?
Yes. Most commercial premises run on a three-phase supply and we design, install and certificate three-phase installations as a matter of course.
If the building needs a bigger supply, for example for machinery, air conditioning or EV charging, the incoming supply is upgraded by the network operator (Northern Powergrid in our area). We handle the application and the on-site work and coordinate the changeover with them.
Can you install data, emergency lighting or fire alarm cabling at the same time?
Yes, and it makes sense to. Once the containment is in and the ceilings and walls are open, adding data cabling, emergency lighting, fire alarm cabling, CCTV or access control costs a fraction of doing it separately later. Tell us what you are planning and we will design it in.
What about asbestos?
Non-domestic buildings built or refurbished before 2000 may contain asbestos, and under the Control of Asbestos Regulations 2012 the person in control of the premises has a duty to manage it, which normally means having an asbestos register or survey. We will ask to see it before we start.
Our team is trained in asbestos awareness and will stop and report anything suspect. Where asbestos-containing materials are in the way of the work, a licensed asbestos contractor removes or encapsulates them first. More at hse.gov.uk/asbestos.
How should we prepare the premises?
We will walk the building with you beforehand and agree what needs moving. Typically that means clearing stock and furniture away from walls where cables run, giving us clear access to the distribution boards and cable routes, agreeing a shutdown plan for IT and any equipment that must not lose power, and sorting keys, alarm codes and out-of-hours access.
We use dust sheets, keep the site tidy and leave each area clean at the end of the day.
Will there be making good, plastering and decorating afterwards?
Usually some. In commercial premises we often use surface trunking, tray or conduit, which keeps disruption and cost down and makes future changes easy. Where cables are chased in or run above ceilings there will be some making good. We tell you where to expect it in the quotation, and we have a list of contractors who can plaster and decorate if you need them.
Is a partial rewire possible?
Yes, and it is common. If part of the installation is recent and compliant, for instance a new kitchen or a floor that was fitted out last year, it can stay. We test what is there, keep what is sound and replace what is not, and issue certification for the work we do. We will be honest with you if the existing parts are not worth keeping.
What do first fix and second fix mean?
First fix is everything that happens before the building is closed up: containment, cabling, back boxes and the positions of everything. Second fix is fitting the accessories, luminaires, distribution boards and equipment once ceilings, walls and decoration are done, followed by testing and certification. On a live commercial site the two are often done area by area rather than for the whole building at once.
What certificates and guarantees do we get?
On completion you receive an Electrical Installation Certificate, the full schedule of test results and updated distribution board schedules, which is what your insurer, landlord or a future EICR will ask for. Where the work falls under the Building Regulations, we notify it through our competent person scheme and you receive the compliance certificate.
Our workmanship is guaranteed for 12 months and materials carry the manufacturer's warranty. If anything attributable to our installation is found to be non-compliant in that period, we put it right at no cost.
Who is responsible for the electrics, landlord or tenant?
It depends on the lease. Commonly the landlord is responsible for the fixed installation up to and including the distribution board serving the unit, and the tenant for the fit-out beyond it, but leases vary and many put full repairing obligations on the tenant. Check your lease, and if you are a landlord or tenant unsure where you stand, we are happy to inspect and set out in writing what belongs to whom.
Do you do domestic rewires?
Yes. Full and partial home rewires are one of the things we do most. See our home rewires page for details.
