Do I need to pay CTG if I own 2 houses and sell 1?

Hi - this is not quite as straight forward as the question implies. My partner and I currently own a house which we are intending to sell but we have the opportunity of buying our next house (a renovation project) whilst we still own our current house. We intend to 'do up' the 2nd house prior to moving into it and then selling our current one. Will we have to pay capital gains tax on our current home just because we own another property?

Thanks in advance of any replies