Chris Pearson said:

I see no particular reason why ordinary persons should be aware of BS 7671

Agreed, but this brings up the whole issue of DIY work full stop (whatever the engineering disciplines involved) ... which is obviously beyond the deliberations of this Forum, and well within the purvey of legal professionals.

At which point, this perhaps takes another turn, but to the best of my knowledge (although I'm not a legal professional, and may well be incorrect) Lord Denning adjudicated that anyone undertaking DIY work had the same duty of care as a professional carrying out the same work?

Chris Pearson said:

I see no particular reason why ordinary persons should be aware of BS 7671 - I wasn't until I trained!

It's not just about electrical work though - in this case anyone thumping bits of steel into the ground would be relevant - whether gardening, digging a pond, erecting a fence, or pegging down a hired birthday bouncy castle.

   - Andy.

Indeed, and a test case I am aware of was someone who had repaired a door handle in a way that it came off in the hand of an unfortunate user, who fell back down some steps and was badly injured. The case fell on if or not a professional carpenter/ joiner  would have used longer screws or realized it was an inadequate repair.
The problem is of course, as one side or the other celebrate their legal success, is that the injured still need looking after while they recover , and the folk who did the job in good faith probably don't deserve to be financially ruined either.

In that sense there is a wider question of the operation of the law of tort. There is an interesting situation in places like New Zealand, where no such legal confrontation is built in, so car insurance is optional, and cheaper, but in effect paid for indirectly by taxation instead. It is not what we have of course, but it is worth realizing that not all the 230V world operates the same way.

In the UK as well we also have the occupiers liability act, many times amended, which muddies the DIY water further.

Mike.

Well, there is a duty of care and a standard of care. The duty of care is pretty broad.

Lord Denning gave many fine judgements, but I do not think that this is one of his.

The leading case is Wells v Cooper [1958], which concerned carpentry rather than electrickery. So the standard expected of a DIYer is that of a reasonably competent DIYer. However, the DIY work must be fairly simple and of the sort that a competent householder might do. I think that a good example might be changing a socket. We might check the Zs afterwards, but I think that the DIYer could be excused for not doing so. It may even be reasonable to extend a circuit.

That does not permit the DIYer to do extensive works. Lord Justice Jenkins wrote, "No doubt some kinds of work involve such highly specialised skill and knowledge, and create such serious dangers if not properly done, that an ordinary occupier owing a duty of care to others in regard to the safety of premises would fail in that duty if he undertook such work himself instead of employing experts to do it for him."

So if you do not know how to do a job reasonably properly, call in a competent tradesman.

I wonder if the Grenfell tower inquiry will add more to AMD4?

mapj1 said:

the injured still need looking after while they recover

That's a job for the good old NHS. Wonderful care guaranteed.

If you succeed in a claim for tort, you get the value of private medical care, whether you used it or not.