10. The compensation to be paid to a person in respect of any compulsory acquisition of an interest in a dwelling which—
(a)has been constructed or substantially modified to meet the special needs of a person in need; and
(b)is occupied by such a person as his residence immediately before the date when the acquiring authority take possession of the dwelling or was last so occupied before that date;
shall, if that person so elects, be assessed as if the dwelling were land which is devoted to a purpose of such a nature that there is no general demand or market for land for that purpose.