Thanks for your question - I am Sam and I am one of the UK tax experts here on Just Answer.
Can you advise
1) how large in the total land and gardens (so also including the main house and any other buildings and land)
2) What have you used the barns for up until now
3) Do you have any planning permission for these barns or are you selling to a developer
4) Are the barns cordoned off or fenced off from the main property and gardens