The energy price cap rose for July 2026, and that shortens glazing payback

The rates for the three months to 30 September 2026

Ofgem's cap for this quarter went up. In its own words, if you are on a standard variable tariff (default tariff) and pay for your electricity by Direct Debit, you will pay on average 26.11 pence per kilowatt hour, with a daily standing charge of 57.19 pence. For gas on the same terms the figures are 7.33 pence per kilowatt hour and a daily standing charge of 29.04 pence.

Standard variable (default) tariff paid by Direct Debit, published by Ofgem on 27 May 2026. Averages across Great Britain; your own rate varies by region and payment method.

Two clarifications. The cap limits the price of each unit and each day, not your total bill, so what you actually pay is still decided by how much energy your home gets through. And these are averages: the exact figure on your statement depends on your region and how you pay.

Why it went up, and the numbers we are not printing

Ofgem's stated reason is short: the increase is a result of higher wholesale gas prices, caused by the ongoing conflict in the Middle East. That is the direction of travel confirmed by the regulator itself.

You will see two other numbers attached to this announcement almost everywhere else, and you will not see them here. One is a headline percentage rise. The other is a typical annual bill. Ofgem's own announcement of these levels states neither, so we quote what it does state: the rates, and the fact that they rose. That is the same discipline we apply across our double glazing news and policy coverage. It makes for duller headlines that hold up better.

What higher unit rates do to double glazing payback

This is the running-cost half of the payback question. A window upgrade buys a fixed reduction in heat loss, measured in kilowatt hours you no longer have to buy, and that reduction does not change when the price of a kilowatt hour changes. What changes is what those avoided kilowatt hours are worth in cash. When the unit rate rises, the same physical improvement returns more each year and the payback period shortens. When rates fall, the reverse happens.

That is the whole of the honest relationship, and it is worth resisting the temptation to go further. It is tempting to take the new unit rates, multiply by an assumed heat loss and produce a fresh, bigger saving figure. Do not: the Energy Saving Trust figure is modelled on a specific house type and fuel mix, so a number built that way traces back to nothing. The published figure stands. Replacing single glazing with A-rated double glazing saves around £85 a year in Great Britain, and around £140 a year in Northern Ireland, on a typical semi-detached house. Those are two separate national figures rather than a range, and a reader in Manchester should be working from the £85 one.

If you want a figure shaped to your own home rather than a typical semi, our energy savings calculator sizes it against your house size and current glazing, and our guide to whether double glazing is worth it sets that saving against the install cost. If you are replacing single glazing rather than tired double glazing, check the grants and funding routes first, because ECO4 runs to 31 December 2026 and a grant changes payback far more sharply than a quarter of higher unit rates ever will.

Every time the cap moves, someone on a doorstep turns up with a shiny new savings figure that has gone up by exactly as much as the price of gas. Ask them where it comes from and it falls apart. Higher rates genuinely do shorten your payback, but the kilowatt hours you save are set by the windows and the walls, not by Ofgem. Get the number from the house.

Tom Bradley, window installer

The part of your bill glazing cannot touch

Standing charges deserve a separate mention: 57.19p a day on electricity and 29.04p a day on gas, paid for being connected at all. No window, no loft insulation and no draught-proofing reduces them by a penny. Glazing bites only on the unit-rate side of the bill, so anyone quoting a saving that quietly assumes your whole bill shrinks in proportion is worth challenging. The same inflated arithmetic turns up in retrofit pitches aimed at the EPC C deadline for landlords.

Read this page with its date attached

This article covers one quarter, and only one: 1 July to 30 September 2026. Ofgem has confirmed that the levels for 1 October to 31 December 2026 will be published by 26 August 2026. That is about ten days after this was written, which means the rates above have a short and entirely predictable shelf life.

So treat them accordingly. If today is past 26 August 2026, a newer set of figures exists and the numbers here describe a quarter that has been superseded. The directional point survives the update either way: whichever direction the cap moves, it moves the cash value of a fixed reduction in heat loss with it. The physics of the window does not change, only the price tag on the heat it keeps in. That is why fabric measures hold their place in longer-term policy such as the Warm Homes Plan, which is built on cutting demand rather than on any one quarter's price.