There is a number people want here and it does not exist. Annual consumption is set by floor area, fabric and climate, and those vary by a factor of three across the housing stock that actually burns oil. What follows is a model, its assumptions are printed, and you should replace them with your own.
The model, stated
- Demand per square metre per season, in kilowatt hours: 165 for solid wall, 120 for part insulated, 85 for well insulated. These are working assumptions on the same scale as published stock modelling, not measured values for your house.
- Kerosene delivers 10.452 kilowatt hours per litre of gross energy.
- Boiler efficiency of 90% for a modern condensing unit. A nineteen year old non-condensing boiler is closer to 75%, which raises litres by roughly a fifth for the same warmth.
- No adjustment for hot water beyond what is already inside the demand figure, and none for wood or electric supplementary heat.
Litres a season by property
| Property | Floor area m2 | kWh per m2 | Litres, 90% boiler | Litres, 75% boiler |
|---|---|---|---|---|
| Two bed cottage, solid wall, 1900s | 75 | 165 | 1,300 | 1,455 |
| Three bed semi, part insulated | 95 | 120 | 1,200 | 1,345 |
| Three bed detached, well insulated | 120 | 85 | 1,080 | 1,205 |
| Four bed detached, part insulated | 160 | 120 | 2,020 | 2,265 |
| Four bed farmhouse, solid wall | 210 | 165 | 3,750 | 4,200 |
The same table in money
| Property | Litres, 90% boiler | At 90.01p | At the 2024-25 average of 54.13p | At the 2022-23 average of 75.67p |
|---|---|---|---|---|
| Two bed cottage, solid wall, 1900s | 1,300 | GBP 1,170.13 | GBP 703.69 | GBP 983.71 |
| Three bed semi, part insulated | 1,200 | GBP 1,080.12 | GBP 649.56 | GBP 908.04 |
| Three bed detached, well insulated | 1,080 | GBP 972.11 | GBP 584.60 | GBP 817.24 |
| Four bed detached, part insulated | 2,020 | GBP 1,818.20 | GBP 1,093.43 | GBP 1,528.53 |
| Four bed farmhouse, solid wall | 3,750 | GBP 3,375.38 | GBP 2,029.88 | GBP 2,837.63 |
What an old boiler costs
The efficiency gap between 90% and 75% is not fifteen percent of your bill. It is fifteen percentage points of a divisor, which is a twenty percent increase in litres. On the three bed row that is 145 litres a season, or GBP 130.51 at today's reading. Over ten years, at prices in the range this series has actually printed, that is the cost of the boiler.
Fills per season
A 2,500 litre tank takes about 2375 litres from empty, which is GBP 2,137.74. A house burning 1,300 litres a season fills once and tops up. A house burning 3,750 fills twice and watches the gauge. That difference changes which timing strategy is even available to you.
Primary sources for this page
- DESNZ Quarterly Energy Prices, table 4.1.1Monthly typical retail price of standard grade burning oil, the fuel sold to UK households as kerosene. Priced on the Monday nearest the 15th of the month, for deliveries of up to 1,000 litres, VAT at 5% included. This is the only official UK-wide domestic heating oil price series.
- NOAA heating degree daysThe degree-day basis for the annual burn model on this site.
- EIA Residential Energy Consumption SurveyHousehold fuel shares and consumption. Used for context, never for a price.
- OFTECTrade body for the UK oil heating industry. Registration scheme for technicians. Cited for installation practice, not for prices.