[Closed] What's the most cost effective way of heating a house?

TBH in answer to the OP if it's in the UK, it's likely to be insulated and "sealed" to the absolute legal minimum. So anything you heat it with is going to cost you a fair bit.
I was pretty amazed at how cheap our new place was to heat, even when it switched over to pure electric when a valve failed. It's 4 or 5 times the size of either of my last two places in the UK, and costs about the same as the modernised 1940s mid terrace did to heat. And about 75% of the cost of an 80s build end terrace.

If it's your place, I'd be looking at what improvements you can make to save the heat you've already got rather than anything else.