OK, basically you can sell your primary private residence and not pay any tax.
Definition of private, primary residence is one that you have lived in sometime during the last three years.
Alternatively, if someone related to you is living there, you may be able to write a letter stating that the house is owned by you, but is *their* private primary residence, and you may therefore be able to sell it again with no tax liability.
For best advice you'll need a proper expert - I'm sure there are ways and means, but it may cost you a few hundred pounds to get it sorted officially. Well worth it compared to losing 40% of the selling price.
Where's your house in the UK? I could sell mine and move into yours and send you my money
