Home Heating Cost & Comparison Calculator

Home Heating Guide

What do I need to know about UK Heating Energy Costs 2026?

Energy unit costs (Ofgem price cap, Q3 2026 — 1 July to 30 September): gas: approximately 7.33p/kWh. Electricity: approximately 26.11p/kWh. Heating oil: approximately 7p/kWh (fluctuates significantly). LPG: approximately 9-12p/kWh. Average UK gas boiler: 85-92% efficiency (condensing). A 3-bed semi-detached house with average insulation: approximately 12,000-14,000 kWh annual heating demand. At 6.4p/kWh gas (90% efficiency): 13,000/0.90 × 6.4p = £924/year. Gas remains the cheapest domestic heating fuel per kWh — but electricity-based heating (heat pumps, electric radiators) costs more per kWh of delivered heat unless the electricity price gap narrows significantly.

What's the key thing to understand about Heat Pump Economics?

Heat pumps move heat rather than generate it — using 1 unit of electricity to deliver 2.5-4 units of heat. COP (Coefficient of Performance): a measure of heat pump efficiency. ASHP typical COP: 2.5-3.5 (seasonal average). GSHP: 3.0-4.5. At electricity 28.6p/kWh and COP 3.0: effective heat cost = 28.6/3.0 = 9.5p/kWh. Compare with gas at 6.4p/kWh (90% efficiency) = 7.1p/kWh effective. Heat pumps currently cost more per unit of heat than gas in the UK. This changes if electricity prices fall relative to gas, or if the gap between the two narrows through policy changes to how the two fuels are taxed and priced.

What do I need to know about Insulation First?

The most cost-effective way to reduce heating bills is always to reduce the heating demand first — before changing the heating system. Priority order: loft insulation (if absent): payback 1-2 years, often partially or fully grant-funded. Cavity wall insulation: payback 2-4 years. Double glazing: longer payback (8-15 years) but significant comfort improvement. Draught-proofing: payback under 1 year. Hot water cylinder jacket: payback under 6 months. Heating system improvements: a smart thermostat, zone controls, and regular boiler servicing are all lower-cost ways to reduce heating waste before considering a larger insulation project.

What do I need to know about Heat Pump Grants?

Boiler Upgrade Scheme (BUS) 2024: £7,500 grant toward ASHP installation. £7,500 grant toward GSHP. No means-testing — available to any eligible property. To qualify: must be replacing a fossil fuel boiler (gas, oil, LPG). Must be in England or Wales. Must use an MCS-certified installer. Budget: £7,500 covers a significant portion of typical ASHP installation costs (£10,000-15,000 typical for a 3-bed house). After grant: net cost £2,500-7,500 for ASHP. ROI depends heavily on the gas-to-electricity price ratio — currently, that ratio makes heat pumps a good financial choice for some households and a marginal one for others, which is why running the actual numbers for your home matters more than a general rule.

What's the key thing to understand about Heating System Options and Their Cost Profiles?

Different heating system types carry quite different combinations of upfront cost, running cost, and installation complexity, which affects which is the right choice for a given property. Gas central heating remains widespread and relatively cheap to install in properties already connected to the gas network, with running costs that have historically been lower per unit of energy than electricity, though this varies by market and over time, and gas boilers have a finite working lifespan requiring eventual replacement. Electric heating (storage heaters, electric radiators, or heat pumps) avoids the need for a gas connection and its associated safety and maintenance considerations, but running costs depend heavily on electricity pricing and, for heat pumps specifically, on the efficiency achieved in that particular property. Oil and LPG heating serve properties off the main gas grid, generally with higher running costs than mains gas but lower than unsubsidised electric resistance heating, and require on-site fuel storage (an oil tank or LPG cylinders) with the associated cost of periodic refills that can fluctuate significantly with wholesale fuel prices. Biomass (wood pellet or log-burning) systems can offer competitive running costs in the right circumstances, particularly with access to a cheap or free fuel supply, but require more hands-on management (fuel loading, ash removal) than fully automated gas, oil, or electric systems, and upfront installation costs for a proper biomass boiler system are often higher than for more conventional alternatives.

What should I know about Sizing a Heating System Correctly?

A heating system that's either oversized or undersized for a property's actual heat demand causes real problems beyond simple inefficiency. An oversized system — more common historically, since installers have sometimes erred toward larger systems 'to be safe' — cycles on and off more frequently than an appropriately sized system would, which reduces efficiency, increases wear on components, and can make temperature control less comfortable, since the system reaches the target temperature quickly and then must shut off repeatedly rather than running steadily. An undersized system struggles to reach a comfortable temperature at all during the coldest periods of the year, which is particularly noticeable with heat pumps if sized without properly accounting for the property's genuine heat loss, since an undersized heat pump may simply be unable to keep up with demand on the coldest days of winter even if it performs adequately for most of the heating season. Correct sizing requires a proper heat loss calculation for the specific property — accounting for floor area, ceiling height, insulation standard, window area and glazing type, and local climate — rather than a rule-of-thumb figure based on floor area alone, since two similarly sized properties with very different insulation standards can have substantially different actual heat demand. This calculation is particularly important, and particularly often skipped or done poorly, when installing heat pumps, since their efficiency and comfort performance is more sensitive to correct sizing than a simple gas boiler, which has more capacity to simply run harder (at reduced efficiency) if slightly oversized for the property.

What do I need to know about Comparing Running Costs Across Heating Types?

Different heating systems convert fuel into usable heat at very different efficiencies, so comparing fuel price per kWh alone is misleading — what matters is the delivered cost per kWh of actual heat, which combines the fuel price with the system's efficiency or COP (coefficient of performance).

*Illustrative only — actual delivered-heat cost depends on current fuel and electricity tariffs, which change frequently and vary by region and supplier. This is also why heating cost comparisons published at a single moment in time can go stale within months — the gas-to-electricity price ratio moved enough between 2022 and 2024 alone to flip the relative running cost of heat pumps versus gas boilers for a typical UK home, so any specific comparison should be treated as a snapshot rather than a permanent ranking.

What do I need to know about a Worked Example — Annual Heating Cost Comparison?

Worked example: a home with an annual heat demand of 12,000 kWh, compared across three heating types using illustrative example tariffs (always check current prices for an accurate figure). Gas boiler (88% efficient, gas at an illustrative 6p/kWh): Gas input = 12,000 ÷ 0.88 = 13,636 kWh; Cost = 13,636 × £0.06 = £818/year Air source heat pump (COP 3.2, electricity at an illustrative 25p/kWh): Electricity input = 12,000 ÷ 3.2 = 3,750 kWh; Cost = 3,750 × £0.25 = £938/year Direct electric heating (100% efficient, electricity at an illustrative 25p/kWh): Electricity input = 12,000 kWh; Cost = 12,000 × £0.25 = £3,000/year At these illustrative rates, the heat pump comes out a little more expensive to run than gas but dramatically cheaper than direct electric resistance heating — and the gas-versus-heat-pump comparison is genuinely close, meaning the result flips depending on the actual gas and electricity prices in force at the time, the COP the heat pump achieves in practice, and whether a time-of-use electricity tariff lets the heat pump run more cheaply overnight. Direct electric heating, by contrast, is reliably the most expensive of the three for any home with meaningful year-round heat demand, because it gets no efficiency multiplier at all from a heat pump's COP or a boiler's combustion efficiency. Insulation standard changes the comparison more than the heating system choice alone: a poorly insulated home with an annual heat demand of 20,000 kWh rather than 12,000 kWh pays roughly 67% more for whichever heating system it uses, since every figure above scales linearly with heat demand — which is why most independent advice puts fabric improvements (loft insulation, cavity wall insulation, draught-proofing) ahead of swapping the heating system itself as the first step in cutting a heating bill.