What is the cheapest way to heat a house? New calculations show which heat sources are the most profitable
The costs of home heating and hot water were estimated for a building with an area of 150 m2, with average insulation, inhabited by a family of four.
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You have to pay the most for oil heating – the annual cost is PLN 10,448. Gas boilers (PLN 8,810) and non-class wood boilers, the so-called “Cinderellas” (PLN 8,631).
A cheaper alternative are eco-design boilers: PLN 6,605 per year for a wood boiler and PLN 5,580 for a coal boiler. Pellet heating, despite its growing popularity, already costs PLN 8,022 per year.
The lowest bills are generated by heat pumps with underfloor heating – depending on the type of device, it is PLN 5,269 or 4,532 per year.
Everyone can check how much they will pay for heating their home
Every homeowner can independently compare the profitability of different heat sources using the heating cost calculator, which is updated quarterly. Just enter the building's area, number of inhabitants and insulation level to obtain individual calculations.
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The analysis of the Polish Smog Alert shows that heating prices have changed significantly over the last year. In the period from October 2024 to September 2025, gas heating became cheaper by 7% and coal heating by 10%. In turn, the price of pellets has increased by almost 8%, and using a boiler for pieces of wood is now 7% more expensive. than a year earlier. The costs of using heat pumps remained at the same level.
House insulation – the key to savings
Comparing the costs of heating houses with different levels of insulation shows how important building insulation is.
In the case of a house without insulation, the so-called “energy vampire”, heat consumption reaches 200 kWh per year per square meter. For a house with average insulation (10 cm of wall insulation, 15 cm of attic insulation) this is already 120 kWh per year per square meter.
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The more expensive the heat source, the greater savings can be achieved through better insulation. For example, in the case of gas heating, the difference in annual costs reaches PLN 4,608, and in the case of a pellet boiler – PLN 4,691.
New technical standards versus old construction
Experts from the Polish Smog Alert compared a house without insulation with a building that meets the current technical standards in force from 2021 (Standard WT2021).
New houses and those undergoing thorough modernization must have walls insulated with a layer of 17 cm, attic 25 cm, triple-glazed windows, and heat consumption should not exceed 55 kWh per year per square meter. Calculations show that annual savings for gas heating amount to PLN 8,353, and for a pellet boiler – PLN 8,502.
Piotr Siergiej, spokesman for the Polish Smog Alert, emphasizes that the savings resulting from insulating an old house to current standards are very high.
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Notes that the amounts given apply only to one year, and the cost calculator may be a good starting point for people planning thermal modernization or replacing a heat source. Sergei also encourages you to perform a professional energy audit to accurately assess the potential benefits in a specific case.
How the data was collected and where the calculations came from
Monitoring of solid fuel prices was carried out on September 22-25, 2025. Two fuel depots were checked in each voivodeship, which gave a total of 32 control points throughout Poland. Depots from different towns were selected to obtain representative data.
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The PAS heating cost calculator was developed based on a tool prepared by the Industry Agreement for Energy Efficiency (POBE). The data used in the calculator is updated every three months, which allows you to keep track of price changes and the profitability of individual heat sources.
