How to decrease your warming costs?

If you are living in a big, own home, you probably are happy because of that, mostly during summer time. But what about winter? How much money you are spending each year for warming? When your building is older then ten years, it perhaps doesn’t have a decent wall insulation. Or probably also you don’t have a modern windows which should safe your house from loosing the hot air. If you like to cut your costs, you have to invest some cash first.