Moving in for six months won't make a difference. However the last 18 months of ownership are discounted when assessing private residence relief so only six months of your time owing the property would be subject to capital gains tax so that is 6/120 months x the gain x your current tax rate. If that is less than the £11,100 CGT allowance there will be no tax to pay. I hope that helps. Please leave a positive rating so that I am credited for my time.