The criteria for a property requiring a mandatory HMO licence is changing. From 1st October 2018 it will be mandatory for there to be a licence for any property (with very limited exceptions) that contains five or more occupants comprising two or more households, with shared facilities. This applies to any premises regardless of how many storeys the property has (previously this applied only to premises with three or more storeys). It is a requirement that if not already licensed, a licence must be applied for by 1st October 2018; there will be no grace period.
In addition the requirements for minimum bedroom size will apply. The sizes will be dependent on how many people sharing a bedroom and their ages. If a property has an existing HMO licence and the room requirements are below the minimum, the requirements will not apply until an application is made for a further licence and even then the Local Authority has the ability to grant a grace period for alterations to be made or for a tenancy to end.