The rent payable under a lease is chargeable consideration for LBTT. For LBTT it is the actual rent payable for each year of the lease which is used. If there is a chargeable transaction which wholly or partly consists of rent or other consideration but is not apportioned (e.g. a service charge which is lumped in with rent as one single payment), the whole of that consideration is to be treated as rent and is chargeable to LBTT.
Where the landlord has elected to waive exemption from VAT as at the effective date, the rent for LBTT purposes includes the VAT chargeable. An option to tax made after the effective date does not affect the rent for the purposes of the 3 year review.