Increase in fair rent in what cases admissible

Save as provided under section 5, when the fair rent of a building or rented land has been fixed under section 4, no further increase in such fair rent shall be permissible except in cases where some addition, improvement or alteration has been carried out in the building or rented land at the landlord's expense and if the building or rented land is then in the occupation of a tenant, at his request: Provided that the fair rent as increased under this section shall not exceed the fair rent payable under this Act for a similar building or rented land in the same locality with such addition, improvement or alteration and it shall not be chargeable until such addition, improvement or alteration has been completed. A party may appear before the Controller either in person or by a recognised agent provided that if the Controller so directs the party shall appear in person.