How we calculate heating costs

Heat demand

We start from the yearly heat demand for space heating: the heated floor area multiplied by the demand rate for the selected insulation standard.

When you include hot water, we add about 900 kWh a year for each person in the household.

Insulation standards

The rates are averages. Real consumption depends on the shape of the building, ventilation, windows, climate zone and the temperature you keep at home.

• Passive house: about 15 kWh/m²·yr
• Low-energy: about 40 kWh/m²·yr
• New, Polish WT 2021 standard: about 60 kWh/m²·yr
• Insulated, built after 2000: about 100 kWh/m²·yr
• Uninsulated, built before 1990: about 200 kWh/m²·yr

Cost for each heat source

The energy you have to buy equals heat demand divided by device efficiency. For solid fuels we convert kWh into kilograms using the calorific value.

Prices

The calculator starts with prices that always come with a date and a source. Electricity is the average of the G11 tariffs approved by URE for the four largest suppliers, gas is the myORLEN tariff with PSG distribution charges, and pellets and eco-pea coal are median prices from surveys of producers and fuel depots. Gas and electricity prices are gross amounts per kWh including distribution.

Your own price may differ from the average, for example because of a different grid operator or fuel supplier. You get the most accurate result when you enter prices from your own bill or fuel invoice. Even then the result is an estimate for a typical heating season.

Fixed charges (subscription, capacity fee) and the purchase cost of the device are not included.

Rounding and limits

• Costs are rounded to whole zloty, energy to whole kWh, solid fuels to 0.1 t.
• The result is an estimate for a typical heating season. It does not replace an energy audit or an energy performance certificate.
• The SCOP of a heat pump depends on the flow temperature. With high-temperature radiators it can be lower than 3.5.