A person must not discriminate by refusing to allow another person with an impairment to alter accommodation to meet the other person’s special needs if—
(a) the alteration is at the expense of the other person; and
(b) the alteration does not require an alteration to the premises of another occupier; and
(c) the action required to restore the accommodation to its previous condition is reasonably practicable; and
(d) the other person undertakes to restore the accommodation to its previous condition before leaving it, and it is reasonably likely that the other person will do so.