A lease with a term (or remaining term, as the case may be) in excess of 21 years. This ignores any break clause in the lease (HMRC:VCONST03230).
(Section 96(1), Value Added Tax Act 1994.) Different rules apply in Scotland.
Only a grant, assignment or surrender of such an interest constitutes a supply of goods for VAT purposes (paragraph 4, Schedule 4, Value Added Tax Act 1994).