In a climate I live in (Latvia , -20 degC for a few weeks in winter), reasonable energy consumption for heating of single-family house is around 100kWh/m2/year.

In a climate I live in (Latvia , -20 degC for a few weeks in winter), reasonable energy consumption for heating of single-family house is around 100kWh/m2/year. My 200m2 house is slightly worse at ~120kWh/m2/year, or around 24MWh of energy per year (that also includes domestic hot water though). With a ground/water heat pump it should translate to ~5MWh of electricity per year, or about the same as my current yearly electricity consumption.