That seems like a rather unfair suggestion. The scheme operators clearly need to require their members to operate to some set of detailed written standards and it would make no sense for them to re-invent the wheel by creating their own standards. They are, of course, as free as everyone else to make their own interpretation of BS7671 when there is less than total detail/clarityIs this because the scheme operators cannot themselves evaluate the merits of an installation designed using common sense, basic principles and manufacturers data about components and cables ? They pass the buck for safety onto British Standards people.but that the schemes require their members to comply totally with BS7671.
I'm not sure that's fair, either. In general, BS7671 indicates only minimum standards and actually says that other approaches are acceptable if they exceed the requirements of BS7671. I think that it is the people who make judgements about compliance in less-than-straightforward situations that are potentially an issue in situations such as you describe.It is ironic that an installation designed to a higher standard of safety than BS7671 requires cannot easily be installed by a member of a scheme yet can be installed by a DIYer where the LABC can evaluate using common sense, basic principles and manufacturers data about components and cables.
Kind Regards, John.