CGT on Remortgaged Property

I have owned a property for 30 years (bought for £25k), after owning the property for approx 5 years I remorgaged (an extra £35k) to have some work done on it. For the past 15 years the property has been rented out to a long term tenant who has recently moved out. Do I have to pay CGT on any profit above the original purchase price or is it something else? I remember seeing something about using the value of the property in 2015? I would really like to sell but if the CGT is on the original price I don't think the sale price will cover the remaining mortgage and the CGT 😕 Any thoughts would be much appreciated.

Hi,
If you are UK resident, it is based on the original purchase price. You can deduct the costs for any capital improvements as well as selling costs to work out any gain due. Please refer to guidance using the links below:
CG15180 - Expenditure: enhancement expenditure
CG15250 - Expenditure: incidental costs of acquisition and disposal
Thank you