if the responsible person follows their instructions and then the consultant suggests a much cheaper way of achieving the same level of safety presumably the RP could seek redress using civil law?
Possibly but I wouldn't think that he is likely to win.
The responsible person should have complied with the order, he did not hence the need to serve a notice. If he is not happy with the notice he could of course appeal the notice.
I dont think a Court would be too sympathetic to such an idividual who goes through all the aforementioned and only then decides to appoint a consultant who discovers a cheaper alternative.
The greater danger is that if the notice is too woolly it may be deemed invalid by the Court.
Case law B.T Fleet Ltd vs McKenna 2005
Improvement notices under s.21 of the Health and Safety at
Work Act 1974 should state what was wrong and why it was
wrong. The notice had to be clear and easy to understand. If the
statutory option was exercised so as to proscribe how a recipient
could comply with a notice, any directions given as to
compliance formed part of the notice and, if confusing, could
operate to make the notice invalid