[DharmaPolice]

I'd argue that insulation should be the first thing people consider unless they know their home is already well insulated. It's all very well having energy efficient heating systems but if most of the heat generated leaks straight outside then I'd question whether that's efficient overall. Particularly in smaller dwellings, you can reduce the amount of heating you require each day during winter - often to nil.

[PaulDavisThe1st]

In theory I'd agree that you should insulate first. But as others have pointed out, on some older houses, insulation can be difficult to accomplish (especially true in non-wood-framed housing). In such cases it is still a better idea to use LESS energy (because of a COP above 1) to heat that space than it is to use resistive or combustion methods (which have a COP less than 1).