But what to do about it?

Wholesale return to TN-S?

Or do like the French and simply not provide an Earthing facility at all (and make everyone go TT)?

Or stick with PME and modernise the cables?

Or stick with PME and add some kind of mitigation - e.g. devices to detect a broken PEN and report it and/or disconnect (could even be built into the new smart meters with modest changes).

(BTW I see diverted N currents not being quite the same thing as broken PENs - the former can occur even in a fault-free system under some circumstances)#

   - Andy.

I thought the recommendation at the bottom of 411.4.2 was the answer to "what to do about it"..

"it is recommended that an additional connection to earth, by means of an earth electrode ..............."

Yes?

I assume most of us are avoiding this recommendation? I tend to do commercial works in big concrete jungles - so this doesn't come up, or at least I've never considered it........perhaps I should. I can barely tell what sort of supply it is in a big switch room and would probably be wrong, let alone even beginning to decide if an earth electrode is required. The building steels will be bonded which is the same thing, so scratch that - no need for me to consider it. 

I thought the recommendation at the bottom of 411.4.2 was the answer to "what to do about it"..

"it is recommended that an additional connection to earth, by means of an earth electrode ..............."

Yes?

I assume most of us are avoiding this recommendation? I tend to do commercial works in big concrete jungles - so this doesn't come up, or at least I've never considered it........perhaps I should. I can barely tell what sort of supply it is in a big switch room and would probably be wrong, let alone even beginning to decide if an earth electrode is required. The building steels will be bonded which is the same thing, so scratch that - no need for me to consider it.