Renting principal residence because can't sell- ? CGT

We have our home for 26 years and now need to relocate but can't sell. If we rent our home out and move to rent a property in our new location, do we lose the right to be exempt from CTG if we managed to sell the family home down the line?

No but part of the gain will become taxable, in the case of an eventual sale.

For example, suppose that you sell it in 4 years for € X and the purchase price was £ Y 26 years ago ie in 1984.

The purchase price is indexed by 1.819 or 2.003 depending whether on purchase date was before or after 5th April 1984.

Gain is then X - ( Y x 1.819 / 0.787564) (.787564 converts £ in €)

To calculate the portion of gain that is taxable, you take total time as PPR + 1 year = 26+1=27 and subtract this from total time of ownership ie 30 -27 =3

Then 3 / 30 = 10% of gain is taxable in year of sale less CGT allowance of 1,270

thanks for that succinct response, helps a lot