UK Land law

Andy inherited a registered freehold in 2013, a 4 story townhouse, but felt it too large for him to live alone . thus he decided to live on the ground floor and earn money. now he wishes to sell the property.

Ben (Andy's best friend) occupied the 1st floor in return for 200 per month for '1 year in the first instance'.

Before selling look at the bens interest and if it can restrict the purchase of the house and/or whether a future purchaser would be bound by any of the agreements he made.

(what interest does he have, will the new buyer be bounded by bens agreement, is the agreement a lease or licence? use relevant law and cases)