How much does the Budget 2027 carbon tax cut save on home heating oil?
About €123 a year for a typical oil-heated semi-D, against the rate that was planned for May 2027. The Budget cuts the carbon tax on kerosene and gas to €48.50 a tonne of CO2, until 2030.
- Semi-D: about €123 a year. Detached house: about €197. Both against the May 2027 rate.
- Against the rate planned for 2030, a semi-D avoids about €212 a year.
- 34.5% of homes sold or let are heated by oil, from 76% in Donegal to 6% in Dublin.
- The catch: the Budget documents give no start date for the new rate. The Finance Bill will.
- A heat pump, after SEAI’s grants, lowers the same semi-D’s running costs by about €533 a year.
A rural bungalow near Doon, County Limerick. Detached houses are 56% of the oil-heated homes sold or let.
Twin gable bungalow to east of Doon village · Neil Theasby · CC BY-SA 2.0
Check my home: what oil costs it, and every grant
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The detail
Confirmed in the Budget documents.
Department of Finance, Budget 2027 Tax Policy Changes, 5.1: “Carbon taxes on kerosene and on natural gas will be reduced to €48.50 t/CO2 emitted until 2030.” Before the Budget the rate was due to go from €63.50 to €71 on 14 October and €78.50 on 1 May 2027 (TSG 26/09). Every euro figure here is measured from the Budget’s €48.50. Budget 2027: what changed for home energy tracks every measure.What the cut is worth a year
A typical oil-heated home sold or let, by type: the carbon tax it avoids against the planned rises. Our model
The carbon tax on home heating fuels was due to rise on 14 October 2026. Published figure
The current Carbon Tax is €71 per tonne of CO2 emitted (t/CO2) for auto fuels and, due to the deferment of 1 May carbon tax increases, €63.50 t/CO2 on all other fuels. This will increase to €78.50 t/CO2 on 14 October 2026 for auto fuels and €71 t/CO2 for other fuels.
Department of Finance, Tax Strategy Group paper TSG 26/09, Para 120, 6 Oct 2026
And again on 1 May 2027. Published figure
In line with the carbon tax trajectory, the carbon tax on other fuels is scheduled to increase to €78.50 t/CO2 on 1 May 2027.
Department of Finance, Tax Strategy Group paper TSG 26/09, Para 121, 6 Oct 2026
About €123 a year for a semi-D, €197 for a detached house
Against the 2030 rate the plan was heading for, €212 and €338 a year, if the rate holds that long.
Each bar is the carbon tax a typical oil-heated home of that type would not pay in a year, at the Budget 2027 rate on kerosene of €48.50 a tonne: the black bar against €78.50 (May 2027), the grey bar against €100 (2030). A litre carries 8.6c less against the May 2027 rate and 14.8c less against 2030, VAT included. "Typical" is the middle (median) home of each type in the BER file.
EstimateThe litres are the BER's standard calculation for each home, at a standard heating pattern, not a metered bill. Households that heat fewer rooms or fewer hours burn less, most of all in homes with low ratings, so read these as the most a typical home of each type would save.
Sources: SEAI BER Research Tool, CC BY 4.0, 8 Sep 2026 · Department of Finance, TSG 26/09, Table 15, 6 Oct 2026
The numbers
| Home | Oil a year (BER) | Saved vs May 2027 rate | Saved vs 2030 rate |
|---|---|---|---|
| Detached house | 2,280 litres | €197 | €338 |
| Semi-detached or end-of-terrace | 1,430 litres | €123 | €212 |
| Mid-terrace house | 1,370 litres | €118 | €202 |
| Apartment | 1,530 litres | €132 | €226 |
Download the data (CSV)Download this chart (SVG, with its source)
On a 500 litre tank, the Department of Finance’s own table puts the carbon tax at €91.26 today, €112.82 at the May 2027 rate (both with VAT). At the 2030 rate of €100 it would be about €144. Published figure
Kerosene* € 91.26 € 10.78 € 10.78 € 112.82
Department of Finance, Tax Strategy Group paper TSG 26/09, Table 15 (500 litre tank), 6 Oct 2026
The lower the BER, the more the cut is worth
Euros a year against the May 2027 rate, by house type and BER letter. Our model
A G-rated detached house: about €295 a year; a C-rated one, €176
Under each euro figure: the oil the BER calculates for the middle home of that type and letter.
| BER | Detached | Semi-D or end-terrace | Mid-terrace | Apartment |
|---|---|---|---|---|
| A | €1341,560 litres | – | – | – |
| B | €1681,950 litres | €931,080 litres | €76880 litres | – |
| C | €1762,040 litres | €1091,270 litres | €901,050 litres | €82950 litres |
| D | €1862,160 litres | €1351,570 litres | €1211,410 litres | €1011,180 litres |
| E | €2132,470 litres | €1671,940 litres | €1501,740 litres | €1531,780 litres |
| F | €2382,770 litres | €1992,310 litres | €1732,010 litres | €1932,240 litres |
| G | €2953,420 litres | €2492,890 litres | €2242,590 litres | €2472,870 litres |
The letter is the 24 May 2026 BER scale, worked out from each certificate's kWh per square metre. A dash: fewer than 100 oil-heated certificates of that type and letter. Oil-heated homes sold or let, assessed 2019 on.
EstimateThe BER's standard calculation of oil use, not a bill; see the note under figure 1.
Sources: SEAI BER Research Tool, CC BY 4.0, 8 Sep 2026 · Department of Finance, TSG 26/09, Table 15, 6 Oct 2026
Oil heats 76% of homes sold or let in Donegal, 6% in Dublin
Every county, BER certificates for a sale or letting, 2019 on. BER assessment
Donegal 76.4%, Dublin 6.1%
Ireland: 34.5% of 265,846 certificates.
Each bar is the share of a county's BER certificates for a sale or private letting, assessed 2019 on, whose main space heating is oil. Certificates, not homes: homes that never change hands are missing, and a home certified twice counts twice.
Sources: SEAI BER Research Tool, CC BY 4.0, 8 Sep 2026
The numbers
| County | Heated by oil | Certificates |
|---|---|---|
| Donegal | 76.4% | 7,813 |
| Monaghan | 70.8% | 2,320 |
| Wexford | 69.6% | 8,839 |
| Mayo | 68.9% | 7,317 |
| Roscommon | 68.8% | 3,600 |
| Leitrim | 66.6% | 2,448 |
| Longford | 66.4% | 2,628 |
| Cavan | 64.6% | 4,086 |
| Tipperary | 63.9% | 7,082 |
| Kerry | 60.6% | 6,952 |
| Sligo | 60.4% | 4,156 |
| Offaly | 57.8% | 3,370 |
| Clare | 57.1% | 6,074 |
| Westmeath | 53.6% | 5,348 |
| Galway | 52.9% | 12,651 |
| Kilkenny | 49.9% | 3,922 |
| Carlow | 43.7% | 3,293 |
| Laois | 42.2% | 4,165 |
| Meath | 40.5% | 8,329 |
| Wicklow | 37.2% | 7,771 |
| Louth | 35.9% | 6,577 |
| Limerick | 35.3% | 10,808 |
| Waterford | 34.9% | 7,219 |
| Kildare | 34.3% | 10,655 |
| Cork | 31.7% | 27,760 |
| Dublin | 6.1% | 90,663 |
Set against a heat pump
The same typical homes, on SEAI's median prices, grants and fuel prices. Our model
Ten years in a semi-D: the cut is worth about €1,235; a heat pump about €3,084, after the part the grant leaves
Ten years of the cut against the May 2027 rate, beside ten years of a heat pump’s lower running costs less what SEAI’s median price leaves to pay.
| Home | Carbon tax cut, 10 years | Heat pump left to pay | Oil a year | Heat pump a year | Heat pump, 10 years net |
|---|---|---|---|---|---|
| Detached house | €1,966 | €2,500 | €2,925 | €2,021 | €6,547 |
| Semi-detached or end-of-terrace | €1,235 | €2,241 | €1,837 | €1,305 | €3,084 |
| Mid-terrace house | €1,179 | €1,500 | €1,754 | €1,233 | €3,710 |
Left to pay: SEAI's median heat pump price for that kind of home (January to June 2026) less the most SEAI pays for the heat pump, the radiators and pipework, and the boiler scrappage grant. Oil a year: the BER's litres at SEAI's €1.283 a litre (1 Jul 2026). Heat pump a year: the electricity for the same heat at 34.38c a kWh, the pump making 3.5 units of heat per unit for heating and 2.5 for hot water. Ten years: ten times the yearly difference, less the part left to pay, at today's prices. Apartments are left out: few are heated by oil, and SEAI's apartment grant is more than its median apartment job.
EstimateOur model, not a quote: no standing charges, servicing or price changes, and it assumes the house needs no other work first. Many older homes need insulation or a technical assessment before a heat pump suits them.
Sources: SEAI BER Research Tool, CC BY 4.0, 8 Sep 2026 · SEAI, Domestic Fuel Cost Comparison, 1 Jul 2026 · SEAI heat pump grant and median costs (engine), 6 Oct 2026
The data, and how to cite it
Cite as: FixMyBER analysis of the SEAI BER Research Tool (CC BY 4.0), oil-heated certificates for a sale or letting, 2019 on, file of 8 Sep 2026; carbon tax from the Department of Finance’s TSG 26/09, Table 15. fixmyber.ie/stories/home-heating-oil
Quote the figures freely with a link to this page; the chart and the spreadsheet are yours to reuse on the same terms. Questions about the method: info@usecara.ie.
How we know
- Which homes: Every existing-home BER certificate SEAI publishes for a sale or a private letting, assessed 2019 to 2026-09: 265,846, of which 91,654 name oil as the main space heating. The Census counts oil as the central heating in 40.9% of all homes (Census 2022), more than on these certificates, because homes that change hands are not every home.
- How much oil: The BER works out the energy a home needs for heating and hot water in a standard way. For oil, we divide its figure by 1.1 (the factor the BER method applies to oil) to get the oil burned, then by 10.183 kWh a litre: SEAI's €1.283 a litre over its 12.6c a kWh for the same edition. It is the standard calculation, not a meter reading.
- The carbon tax: Table 15 of the Department of Finance's TSG 26/09 gives the carbon tax on a 500 litre tank of kerosene, VAT included, at €63.50 a tonne (€91.26) and at the May 2027 rate (€112.82). We divide by 500 for a litre and scale to the 2030 rate of €100 a tonne in the same paper; the build checks the table and the rates agree to the cent.
- What we assume: That the Budget's €48.50 a tonne applies to kerosene for the whole year shown. The Budget's Tax Policy Changes do not give the date the new rate starts; the Finance Bill will.
Sources
SEAI BER Research Tool, CC BY 4.0, 8 Sep 2026 · Department of Finance, TSG 26/09, Table 15, 6 Oct 2026 · SEAI, Domestic Fuel Cost Comparison, 1 Jul 2026
Found a mistake? Every fix is dated on Corrections. Method in full: How we know.
See your grants and what you’d pay
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Updated · grants checked · BER file 8 Sep 2026 · How we know · Corrections