Where the landlord proposes to make any improvement in, or construct any additional structure on, any building which has been let to a tenant and the tenant refuses to allow the landlord to make such improvement or construct such additional structure and the Rent Authority, on an application made to him in this behalf by the landlord, is satisfied that the landlord is ready and willing to commence the work and that such work will not cause any undue hardship to the tenant, the Rent Authority may permit the landlord to do such work and may make such other order as he thinks fit in the circumstances of the case.