The energy price cap will rise by 13% from 1 July 2025, adding roughly £180 a year to a typical 3-bed semi’s dual-fuel bill. Martin Lewis broke the news on social media this week, citing Ofgem’s latest quarterly adjustment. The jump, the third increase in twelve months, takes the typical annual bill to around £1,820 for direct debit customers.
As reported by Traders Union, the increase is driven by wholesale gas prices that remain 40% above pre-2022 levels. Ofgem confirmed the figure to Reuters last week. But the headline number masks a deeper problem for UK homeowners: the cap protects against only the worst spikes, not against structural inefficiency in leaky homes.
Who pays, and who doesn’t
The cap applies to default tariff customers on standard variable tariffs, about 28 million households in England, Wales and Scotland. Northern Ireland has a separate price guarantee. Prepayment meter customers will see a similar percentage rise, though their standing charges remain slightly lower under a separate cap.
Households on fixed deals, roughly 6 million, are shielded until their contract ends. But the gap between fixed and variable tariffs has narrowed to under £50 a year, making switches less attractive than they were in 2023. The catch: many fixed deals now lock in higher rates than the current cap, so switching is only worthwhile if the fix is below £1,820.
Ofgem’s own data shows that 42% of households have not switched supplier in the past three years. Those households will absorb the full increase unless they act.
What it costs a typical 3-bed semi
Take a 3-bed semi in Manchester with gas central heating and 12,000 kWh annual consumption. The 13% rise adds £180 to the bill, from £1,640 to £1,820. That is £15 a month extra. For a household on a prepayment meter, the standing charge component (roughly 60p/day for electricity, 30p/day for gas) means the bill starts at £328 a year before a single kWh is used.
The Energy Saving Trust estimates that loft insulation to 270mm saves £180–£250 a year on a semi. Cavity wall insulation saves another £195–£255. Together, those two measures alone offset the entire price cap rise and improve the EPC from D to C, potentially adding 4% to the property’s value, according to Nationwide’s 2024 research.
Heat pumps, often dismissed as too expensive, now cost £7,000–£13,000 installed, but the government’s Boiler Upgrade Scheme covers £7,500 of that. Running costs for a well-insulated semi are typically £300–£500 a year lower than a gas boiler, depending on tariff and usage.
What this misses, the EPC blind spot
The price cap rise is a symptom, not the disease. The UK’s housing stock is among the least efficient in Europe. The average EPC rating is D, and 19 million homes need upgrading to reach Band C by 2035, the government’s target. Every 1°C of indoor temperature above 18°C adds roughly 8% to heating costs. A semi with single glazing and no loft insulation loses heat at 3–4 times the rate of a modern home.
But the cap does nothing to address this. It merely redistributes the cost of inefficiency across all billpayers. The regulator’s own impact assessment shows that households in EPC F or G homes pay £1,200 a year more than those in Band C homes, even on the same tariff. The 13% rise widens that gap.
Documents seen by The Guardian show a separate £180m underspend in the government’s energy efficiency budget for 2024–25. That money was meant to fund free cavity wall and loft insulation for low-income households. The underspend means fewer homes will be upgraded before winter 2025.
What you can do now
Households on standard variable tariffs can apply for a fixed deal through their supplier or a comparison site. Fixed deals below £1,820 are still available from Octopus and EDF, though availability varies by region. Check MSE’s Cheap Energy Club for live rates.
For those who can’t switch, the priority is insulation. Loft insulation costs £300–£500 for a semi and pays back in under three years. Cavity wall insulation costs £500–£1,000 and pays back in under five. Both are eligible for 0% VAT until 2027.
Households with an EPC below C should apply for the Great British Insulation Scheme (GBIS), which offers free or heavily subsidised insulation for low-income homes. Eligibility checks are done through gov.uk. Applications for the Boiler Upgrade Scheme close on 31 March 2027, but funding is allocated quarterly, so early application is advised.
Finally, check your standing charges. Some suppliers charge up to 70p/day for electricity, that is £255 a year before any usage. Switching to a lower-standing-charge tariff can save £50–£80 a year, even if the unit rate is slightly higher.
Frequently Asked Questions
Not directly. Fixed-rate deals are not capped by Ofgem. However, suppliers typically price fixed deals based on future wholesale costs, so new fixes may rise in line with the cap. Existing fixes are locked in until they end.
Yes, if your household income is below £31,000 or you receive certain benefits, the Great British Insulation Scheme offers free loft and cavity wall insulation. Apply through gov.uk. For others, 0% VAT on insulation until 2027 makes the payback period shorter than the price cap rise.
