Capital Gains Tax ( Apportionment )

[GANDONAS22]

Guest house to be sold attracting an overall gain of £55K based on sales minus purchase.
Valuation Office Agency 42% non residential.
When calculating chargeable gain would residential relief be available on the portion of 55K , that is calculating 42% of 55K and then subtracting CGT personal allowances, chattel exemptions etc
Apologies for the novice question, just want to understand how this works
G

[GANDONAS22]

Hi

Thanks to any viewers , managed to get an answer
Cheers
G