employee accomodation

We have a number of new employees who will be relocating in the next two years but in the meantime we are renting a flat that they can use instead of hotels, when they need to be in the office.

They will not be staying on set days and the flat may also be used by board members when visiting.

One of the employees is a director who owns > 5% of the shares.

How do we allocate the benefit in kind?