Survey finding
Single-phase electric supply: what it means for buyers
Single-phase vs three-phase electrical supply matters mainly for EV chargers, heat pumps, and workshops. This page covers when it's a buyer issue and what an upgrade costs.
Last updated: 6 May 2026. Editorially reviewed: 20 May 2026.
Finding
Single-phase electrical supply only
What this usually means
Most UK domestic properties have a single-phase electrical supply (one live, one neutral). Single phase is fine for normal domestic loads, boiler, kettle, oven, EV charger up to 7kW. Three-phase is needed for higher-load EV chargers (22kW+), commercial-scale heat pumps, or properties with workshop loads. Surveyors flag single phase only when the buyer has signalled an interest in a higher-load installation.
Why it matters
Single-phase is not a defect. It's a planning consideration if you want a 22kW EV charger, a large heat pump, or a workshop. Upgrading to three-phase is expensive and often needs the DNO (Distribution Network Operator) to upgrade the supply.
Ask your surveyor
- Check:Is the property single-phase or three-phase?
- Check:Is the consumer unit recent and does it have spare capacity?
Ask the seller
- Check:Has the supply ever been upgraded?
- Check:Are there any electrical loads the current supply has limited (e.g. EV charger, induction range)?
Next steps
- •Get two written quotes from local trades before negotiating with the seller.
- •Speak to your mortgage broker before exchanging if the finding affects mortgageability.
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Tool shortcut
Check the property before you offer
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What you need to know
Severity
Cosmetic. Note for budget but not a negotiation lever in itself.
Typical cost to fix
DNO three-phase supply upgrade: £2,000–£8,000+ depending on local network capacity and distance to the substation. Internal three-phase consumer unit and rewiring: £1,500–£4,000.
Mortgage impact
Not a mortgage issue.
Insurance impact
Not an insurance issue.
When to pull out
Almost never. Pull out only if the property is unsuitable for the buyer's specific high-load plans and upgrade cost is unviable.
When to renegotiate, and by how much
If three-phase is essential to the buyer's plans, get a DNO quote before exchange and negotiate based on cost.
Thinking of pulling out or renegotiating? What to do after a bad survey
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The Survey Decoder explains the wording. The full report adds address-specific flood, subsidence, EPC, crime, listed status, building age and price comparison data, so a single finding isn't judged in isolation.
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Check the property before you offer
Flood, subsidence, EPC, crime, schools, transport, broadband, tenure, age, listed status and price checks where data is available.
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Electrical issues , often sits near single-phase electrical supply only on a survey and is the next thing to check.
Editorial review
Editorial owner: BiteRight Ltd, operator of MyPropertyScan. We review buyer guides against UK public property datasets, RICS survey wording, lender requirements, and common buyer questions.
Pages are updated when source coverage, property-risk guidance, survey cost assumptions, or product checks materially change. Methodology and dataset limitations are explained on the MyPropertyScan methodology page.
Sources used
We use UK public and specialist sources where they are available. Public datasets can be incomplete, delayed, or missing for some addresses. Treat them as a starting point, not as a replacement for professional advice.
Source standard: preference goes to official government datasets, statutory bodies, professional standards, and primary dataset publishers. We cite the source family on the page and explain coverage limits rather than filling gaps with unsupported estimates.