But main problem you have to think about is your windows. Maybe you got, old, wooden ones? They are looking very nice, surely, but it is not enough. If you will replace it for any modern, PCV pieces, you will have a chance to keep plenty of hot air inside of your house. You don’t must to replace every piece at ones, you may do it in couple steps, to avoid too many expenditures in one month. Another important issue is your roof. If you will cover it with some fibreglass mesh, it will also keep your house much warmer during the winter, cause a lot of the air is escaping trough it, probably.
Then, you may invest some of money in external wall insulation. It should be really giant cost, but it is worth it, more here: external paints. Within couple winters, costs of it will come back to you into the warming expenditures. Also, when you want, you could at the end make some interior insulation as well, exerting also fiberglass mesh – it is the best product for all this kind of works. But where you may buy all the materials? It is really simple, go to the closest building store. You will find there all the stuff you need, from screwdrivers to fibreglass mesh.
If you are afraid of cold season, because of huge costs of healing, there is a great solution. You must to proceed an external wall insulation and replace old windows with PCV ones, more information here – eps adhesive. It could help you to save plenty of cash, and it is great for environment, because you will waste much less energy. And the best term to start overhaul like this is spring. So possibly you will consider it?