[pkolaczk]

Technically you're right, but what you really want at home is not generating heat, but having more heat inside. These are not the same things. You can actually move some heat from outside to inside by using a heat pump (powered by electricity), commonly known as "air conditioner". Heat pumps can typically move 2x-6x more heat then they consume energy. So practically their heating or cooling efficiency is 2x-6x better than a resistance-based heater.

As for burning stuff - burning stuff is typically much cheaper, although it is actually the least efficient way of heating, in terms of a ratio between the usable heat you get and the total chemical energy converted to heat.