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What heating system is cheapest to run in Ireland?

In a well-insulated home, a heat pump is usually cheapest per unit of heat delivered because it produces several units of heat per unit of electricity. In a poorly insulated home, running costs depend far more on fabric than on the appliance.

A heat pump with a seasonal performance factor of three delivers three units of heat per unit of electricity. Whether that beats gas or oil depends on the ratio between electricity and fuel unit prices at the time, which moves.

The dominant variable is heat demand. Halving the heat loss of a house halves the bill regardless of the heating system, which is why fabric-first is the standard advice.

How to compare properly

  • Estimate annual heat demand from the BER or a heat loss calculation
  • Divide by the seasonal efficiency of each system
  • Apply current unit prices including standing charges
  • Include maintenance and expected replacement life

Sources

Last reviewed 28 August 2026. General information only — not legal or planning advice.

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