If I sell my only home would I be liable to capital gains tax?

Question We have owned our current house (which has been our home) for the last 20 years. We are considering downsizing by buying a second property, which is in need of modernisation, with the intention of selling our home and then moving into the second property when updating is completed. Would I be liable to pay capital gains tax (CGT) on the sale of my current home?
 
Arthur Weller replies:
From what you have written it would appear that you will not pay any capital gains tax (CGT) when you sell your current home, because all the gain is covered by principal private residence relief. That being so, you would not even have to put this sale on the capital gains supplementary pages of the self-assessment tax return.