Hello, my Daughter lives in a block of 16 flats. She has 75 years or a 99 year lease left to run on her flat. She has asked the owner if she can have an extension to the lease say back to 99 years. The owner has said she and the other 15 tennants can together buy the "reversionary Interest" for £5k per dwelling. What is reversionary interest and is £5k a reasonable sum to buy this interest. How long then would the lease have to run if she went ahead?.