CGT On Split titles

Hello. I am currently selling my flat and basement separately, for £219,995 and £39,995 respectively. When I purchased the flat for £95,000 back in 2017, the flat and basement were purchased with both titles in the price. The basement has only ever been used as storage as it's currently uninhabitable. I'm not sure where I stand on capital gains tax on the sale of the basement, would it be considered to be within the Private Residence Relief, as it was used as an ancillary to the flat? Thanks In advance !

Hi,

No, as they have different title deeds.

Thank you.