This section applies where—
The circumstances referred to in subsection (1)(b) above are that—
In any case to which this section applies the original damage and the further damage shall be treated as one ("the combined damage") and, subject to subsection (5) below—
A fresh schedule of remedial works relating to the combined damage satisfies the requirements of this subsection if the aggregate amount of the costs specified in that schedule does not exceed, by more than 20 per cent., the aggregate amount of the costs specified in any schedule of remedial works to which subsection (3)(d) above applies.
It shall be the duty of the Corporation to specify in a notice under subsection (3)(f) above such works (if any) as are required in order to render the damaged property reasonably fit to be used for the purposes for which it was used immediately before the original damage became evident, not being—
In any case to which this section applies it may be agreed between the Corporation, the claimant and any other person interested—
This section is without prejudice to any liability of the Corporation in respect of the cost of any works executed before the further damage becomes evident.
The Secretary of State may by order substitute for the percentage specified in subsection (4) above (whether as originally enacted or as previously amended under this subsection) such other percentage as he thinks fit.