Central Central Heating - How Would You Go About Installing It In Your Home?

Central Heating - how would you go about installing it in your home? - central

Hello. I am pleased with the offer on a house - but no central heating! If you accept my offer, I am sure that you install some kind of heating it - Radiators and underfloor heating in the bathroom. The house has for many years, without prejudice, it seems, and in fact I get to do things again, the installation of efficient updating of systems.
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But I'm just confused how to do that. Am I the oil / gas / electric ... for example? This has all cost a lot to do? (this is a semi-detached house with 3 beds in passing, if that information helps) and the WHO settings, do I ask you for me? I hear that British Gas is expensive ...
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Suggestions, comments appreciated. Thank you.