You are getting two issue confused here. Yes the restrictions you quote are correct (at present) for loans taken to invest in a company.
However your post suggests you ve bought the premises and are letting it to the company which is a different scenario. You get interest relief (100%) againt the rental income you receive in letting it. You are taxed on the surplus under schedule D Case V.
Its a commercial premises and not residential so there is no interest restriction, so im sincerely hoping your accountant hasnt applied 75% from 7 April 2009 or any of 2010.
Worth checking out.
Regards,
Brian