Lowest heating bill you've ever known?

I knew a man once who had a yearly gas bill of under £40.

He was on a tarrif that did not include standing charged, but this meant the first units of energy were quite expensive. Still he managed to keep his bills extremely low. He even showed my bills to prove it since I was very skeptical.

He had double glazing, cavity wall and loft insulation, but aside from this had an absurd amount of bed covers, and often sat around the house wearing two jumpers. The frugality was something to be both admired, and shocked by.

It's my monthly cost in summer, but in winter mine is about £60, though that is for combined gas and electricity. I'm not sure what proportion is gas use and what is electricity us. Either way, £40/year is beyond insane. I think the gas company was probably a bit suspicious about a meter reading that low.