(1)The local authority may, at any time, extend the period within which any work required by an HMO amenity notice must be completed by such period as it considers reasonable.
(2)But such a period may be extended only where the local authority—
(a)considers that satisfactory progress has been made in carrying out the work, or
(b)has received a written undertaking from the owner stating that the work will be completed by a later date which the authority considers satisfactory.
(3)The local authority must give notice of any extension in accordance with section 158.