The price of Brent crude jumped 8% in a single day last week. That spike, triggered by Iranian missile strikes on Israeli infrastructure, is already feeding through to wholesale gas markets, and UK homeowners will feel the pinch by spring.
As reported by China Daily, the conflict threatens a sustained disruption to supply through the Strait of Hormuz, through which 20% of the world’s liquefied natural gas (LNG) passes. UK gas storage levels are already below the five-year average, and the National Grid has warned of tighter margins this winter.
What it costs a typical 3-bed semi
Ofgem’s price cap stood at £1,717 for October–December 2024. Analysts at Cornwall Insight now project a rise to £1,837 from April 2025 if the crisis deepens, an extra £120 a year. That is the equivalent of two full tanks of petrol for the family car, or a month’s food shopping at Aldi.
The catch is that wholesale prices feed into the cap with a two-month lag. So the full impact of the Iran shock will not hit households until the spring, when heating demand is falling but the baseline standing charge, currently 60p per day for electricity, will remain high.
Who qualifies, and who doesn’t
Households on standard variable tariffs are fully exposed. Those on fixed deals locked in before October 2024 are shielded until their contract ends, but those fixes typically expire within 12 months. The 4.5 million homes on prepayment meters face the highest standing charges and the lowest ability to switch.
Government support, such as the Warm Home Discount (£150 off electricity bills for low-income households), remains in place but has not been expanded. The Energy Price Guarantee, which capped bills at £2,500 in 2022–23, has been scrapped. No new emergency package has been announced.
Geopolitics meets EPC ratings
Here is the editorial angle that most coverage misses: every £100 rise in the price cap widens the gap between a D-rated home and an A-rated home by roughly £80 a year. That is because better insulation, efficient heating, and solar panels reduce consumption directly, not just the unit rate.
Energy Saving Trust data shows that a home moving from EPC band D to C saves about £300 a year on bills. With the cap rising, that saving becomes £380. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. These measures improve EPC ratings by one to two bands.
Yet the take-up remains low: only 45,000 heat pump vouchers were issued in the first year of the scheme, against a government target of 600,000 by 2028. The conflict in Iran should concentrate minds.
What to do by when
Homeowners on standard tariffs should act before the April cap rise. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. For heat pumps, the Boiler Upgrade Scheme runs until 31 March 2027, but installer lead times are already six to eight weeks.
If you cannot upgrade immediately, switch to a fixed tariff today. Fixed deals are reappearing after a two-year absence, the best available is around £1,680, still below the current cap. Use a comparison site accredited by Ofgem’s Confidence Code.
The Iran crisis is not a temporary blip. It is a structural reminder that the UK imports 50% of its gas, and that every homeowner’s bill is a hostage to geopolitics. The only durable insulation from that risk is insulation itself.
Frequently Asked Questions
Not immediately, wholesale price changes take about two months to feed into Ofgem's price cap. The impact is expected from April 2025, when the cap is next reviewed. However, fixed-rate deals may rise sooner as suppliers adjust their forward pricing.
Yes, partially. A typical 3.5 kW solar PV system generates about 2,900 kWh per year, covering roughly 40% of an average household's electricity use. This reduces your exposure to grid price spikes, but you still rely on gas for heating unless you pair it with a heat pump.
