Commercial sites
Utility connections for commercial and mixed-use sites
New supplies for units, offices, shops and mixed-use buildings, plus capacity increases for EV charging, heat pumps and new plant. We work out the load, apply to the right operators, compare offers where the work is contestable and manage it through to live supplies.
New supplies for every kind of commercial building
Commercial connections are rarely standard. The load depends on what the building is for, who will occupy it and what they will plug in. We start there, before anything goes to the network operator or water company.
Industrial units
Single units and estates, often three-phase, with space for tenants' machinery and future fit-outs.
Offices
Heating, cooling, lifts and EV parking, often with landlord and tenant supplies split.
Retail
Shops, food outlets and drive-throughs, where refrigeration and cooking set the load.
Mixed-use
Commercial ground floors with homes above, each needing its own supplies and metering.
Capacity increases for existing premises
Many commercial jobs aren't new connections at all. A business adds EV chargers, swaps gas heating for heat pumps, or brings in new machinery, and the existing supply can't carry the load.
A capacity increase goes through the network operator like a new connection. It needs the existing supply details, the new maximum demand and what is changing. The operator then checks whether its local network can take it, or whether a bigger cable, a new transformer or a new substation is needed.
Since 1 April 2023, demand customers pay for the extension assets that connect them, and wider reinforcement is paid for through network charges. The exceptions are assets built only for you (sole-use assets) and reinforcement costing more than the High Cost Cap of £1,720 per kVA. We check every offer applies this properly.
Do you need a three-phase supply?
Most commercial premises with any real load use three-phase. It spreads the demand across three conductors and is needed by most larger motors, compressors, commercial kitchens, rapid chargers and larger heat pumps.
Moving from single-phase to three-phase is an upgrade the network operator has to approve and build. Whether it is a quick job or a major one depends on what is in the street. If a three-phase cable is already outside, it can be fairly simple. If not, it may mean new cable or network work.
As an indication only, National Grid Electricity Distribution's pricing guide shows about £6,000 plus VAT and 8 weeks from acceptance for a small business supply up to 69 kVA. Other operators publish different figures.
More on electricity connectionsLandlord supplies, EV charging hubs and heat pumps
These are the loads that most often change the size, and the price, of a commercial connection. Each one has to be in the application, not added afterwards.
Landlord supplies
Multi-let buildings need a landlord supply for shared loads: lifts, common-area lighting, plant rooms, pumps, fire systems and car park chargers. We plan the metering layout so each tenant and the landlord can be billed separately.
EV charging hubs
A row of rapid chargers can need more capacity than the building itself. The small "connect and notify" route only covers adding a single item to an existing supply, so a hub needs a full application. We size it for the chargers planned now and later.
Heat pumps
Replacing gas heating with heat pumps moves the whole heating load onto electricity. On a large building this can mean three-phase, a bigger supply or a new substation. We include it before applying, so it isn't found out late.
High-voltage supplies and the 5 MVA rules
Larger sites often connect at high voltage (HV) and own their own transformer. These applications take longer, cost more to prepare and now come with stricter information rules.
Network operators can charge an assessment and design fee for preparing an offer, whether or not you accept it. When the fee is charged varies by operator. National Grid Electricity Distribution, for example, has charged it on issue for all HV-and-above quotations since 1 February 2026.
From 1 June 2026, every network operator requires a minimum set of information for demand applications of 5 MVA and above. Generic dates such as "ASAP" or "TBC" are not accepted. Wider reforms to how large demand joins the queue are aimed mainly at data centres and were still being decided in 2026. Ordinary sites under 5 MVA are not directly affected.
What a 5 MVA+ application must include
- A letter of authority
- Heads of terms, where the applicant doesn't own the land
- A site plan
- A project timeline with real milestones
- A single line diagram, where customer equipment could disturb the network
We put the pack together with your design team so the application is complete when it goes in.
How long does a commercial connection take?
Two clocks matter: how long the operator has to send a quote, and how long the work takes after you accept and pay.
Quotation times
The Guaranteed Standards of Performance set how long a network operator has to issue an offer. They apply to every operator.
| Type of request | Working days |
|---|---|
| Budget estimate, below 1 MVA | 10 |
| Budget estimate, 1 MVA or more | 20 |
| Other LV demand quotation | 25 |
| HV demand quotation | 35 |
| EHV quotation | 65 |
Typical build times
These are National Grid Electricity Distribution's indicative figures, from acceptance and payment. Other operators differ, and highway permits, wayleaves and substations add time.
| Connection | Typical lead time |
|---|---|
| Small business, up to 69 kVA | 8 weeks |
| Large business (HV) | 20+ weeks |
| EHV | 2+ years |
A budget estimate is indicative and not a binding offer. The formal quotation is the offer you accept. Read our lead times guide.
Water and sewer connections for commercial sites
Commercial water applications need flow and occupancy details, not just a number of units. Toilets, kitchens, process water and sprinkler or fire systems all change what the water company has to supply.
For drainage, connecting to a public sewer is done under Section 106, by giving the water company notice and meeting its conditions. If anything other than normal domestic sewage will go down the drain, such as wash water or process waste, the business will also need a trade effluent consent.
On larger sites a pre-development enquiry to the water company can confirm network capacity early. It isn't a legal requirement, but large companies strongly encourage it.
More on water connectionsInformation for a commercial application
- Site address, location plan and site layout
- What the building is for, and floor areas
- Electrical loads in kVA, including plant, EV chargers and heat pumps
- Existing supply details, for an upgrade
- Preferred intake, substation and meter positions
- Water use and drainage layout
- When you need supplies, and any phasing
- Who owns the land, and a letter of authority if you act for the owner
Our fee is fixed and agreed before we start, and our quote is free.
Commercial connection questions
How long does a commercial electricity connection take?
A small business supply can take around 8 weeks from acceptance on National Grid Electricity Distribution's indicative figures, while HV connections are 20 weeks or more. Other operators differ, and substations, wayleaves and road works add time.
Do I need three-phase for my business?
If you run larger motors, commercial kitchens, rapid EV chargers or larger heat pumps, almost certainly. We work out the maximum demand first, so you apply for the right supply.
Can I add EV chargers to my existing supply?
Small single additions to an existing supply can sometimes be fitted and notified to the network operator within 28 days. Anything larger, such as a charging hub, needs an application first, and may need more capacity.
Who pays for network reinforcement on a commercial site?
Since April 2023, demand customers usually pay only for the extension assets that connect them. You still pay for sole-use assets and for reinforcement above the High Cost Cap of £1,720 per kVA.
What changed for large connections on 1 June 2026?
Every network operator now requires minimum information for demand applications of 5 MVA and above: a letter of authority, heads of terms where you don't own the land, a site plan, a milestone timeline and, where needed, a single line diagram.
Will I pay for a quotation I don't accept?
Possibly. Network operators can charge assessment and design fees whether or not you accept the offer. When and how they charge varies by operator.
How long is a commercial electricity offer valid?
Each operator sets its own period, and 90 days is common. The exact period is in the offer letter, so we time applications to suit your programme.
Can you handle the landlord and tenant supplies on a multi-let building?
Yes. We plan the landlord supply for shared loads and the tenant supplies and metering together, so the building is ready to let.
Related services
Electricity connections
Find out moreWater connections
Find out moreMulti-utility connections
Find out moreDisconnections and diversions
Find out moreBuilding homes rather than commercial space? See our pages for developers and self-builders.
Planning a commercial connection?
Send us the site details and the loads you expect. We'll confirm the operators, the route and a clear quote for managing the applications.