No heating? There are human bodies in there.

A passive house is a building whose energy consumption per square meter is very low. Heating requirements of < 15 kWh/m²/year.

That's about two human bodies.

  15 kWh/m²/year * 150 m^2 / ~10,000 h/year ~= 200W

you'll still need electricity for your laptop, microwave, fridge etc.