Capital gains and self assessment

Could you tell me if I can offset a capital expenditure item, such as a new bathroom against Capital Gains tax return on the sale of property as well as utilising the same expenditure in the annual self assessment return for a rented property prior to its sale? Can you also tell me if the capital gains allowance is annual so therefore £3k per year of ownership? So eg, owned second property for 10 years, between 2 people would that be 30k or 60k allowance between the two

Hi,
No, it can only be used once.
If it has been replaced like for like (just up to date) it is rental expenditure.
Iif you have totally enhanced it, it is capital gains.
The allowance is only due in the year the asset is sold so for 24/25 it is £3000.
Thank you.