Where plans of any proposed work have been passed under section 16 above by a local authority, the person by or on whose behalf the plans were in accordance with building regulations deposited with the authority may, and in such cases as may be prescribed shall, for the purpose of obtaining the approval of the authority to any proposed departure or deviation from the plans as passed, deposit plans of the departure or deviation.
Section 16 above applies in relation to plans deposited under subsection (1) above as it applies in relation to the plans originally deposited.