A person can claim IBA on an industrial building which is
temporarily disused
CA32800. If the last time the building
was used it was used for a trade that has permanently ceased or it
was let treat the person as carrying on a property business. You
should then treat allowances as expenses and charges as receipts of
that property business.
There is an additional rule where the last use of the
building was for a trade that has permanently ceased. Treat charges
as receipts of that trade purely in order to allow any deductions
against them which you would allow against a post cessation
receipt.