Are the new regulations for real?

[SimonH2]

In case the pieces haven't fitted to gether yet in anyone's mind ...

Back in 2005 the building regs changed such that loads of electrical work was then notifiable - and of relevance to the thread, it directly mentioned circuits outside such as the OPs extension to the shed.
One of the exceptions to the requirement for notification was if the external circuit was plugged in and was made from fre-fabricated components. Hence pluggable systems suddenly appeared which didn't need notification, which in the vernacular probably does roughly translate as "bypasses regulations". It didn't bypass "Part P", it used the exception allowed for to bypass the bit of law that said you had to pay oodles of cash to notify the system.
This ceased to be the case in 2013 when the building regs for England were cleaned up, and notification was reduced to just 3 items in a list - basically fitting a consumer unit, adding a circuit, or work in the zones of a bathroom. AIUI in Wales they still have the mess that is the 2005 regs.
So Blagdon weren't lying, they were (as I interpret the comments above) just (mis)using rather poor terminology to explain to the non-technical punter they were marketing, to that it was legal for them to install this stuff themselves.

 

[Taylortwocities]

This ceased to be the case in 2013 when the building regs for England were cleaned up,

Cleaned up?
Rather they were watered down, made less effective and removed many of the benefits of the original intent.

 

[ericmark]

I looked at the Blagdon product, and the flaw was in the main you needed to remove the plug and refit it in order to install it, so it was uncertain as to if it complied with the letter of the law.

The idea was you could buy ready made kitchen stuff made in modules and simply plug and play, I don't think the pre-assembled rule was really for garden stuff, however the law is so poorly written it is hard to work out exactly what is permitted, reading the law, it seems you can make up and plug in an extension lead, but if you then want to tidy up the cable and clip it to the wall and put in a couple of screws to keep sockets off the counter in the kitchen, then you should in theory register the work and pay the fees, in practice that's not the case.

English is the problem, the words used are not defined, the BS7671 defines a circuit, but you are allowed it seems under Part P to fit a FCU without registering the work, and under BS7671 that's a new circuit, so Part P is reliant on case law to define what can and can't really be done. I have looked for the Welsh version, and can't find it, neither can I find a Welsh version of BS7671 which would make the whole law void in Wales, although one would be stupid to try and hide behind that, and even to try you would need to be a Welsh speaker.

This sign says in Welsh "I am not in the office at the moment. Send any work to be translated." can you imagine what errors there would be with a document like BS7671? Even in the English version they have already had to issue corrections for the new version before it has even come into force.

As far as I am aware, most of the Part P court cases are about people claiming to be scheme members when they are not, in other words all about money, dangerous work is covered by other laws, it does not need Part P. As to claiming when an appliance turns out to be dangerous, look at all the washing machine fires, the manufacturer seems to be getting away with manslaughter in some cases, so as to claiming from Blagdon I think your going to get nothing.

I have not heard of a single A1 electrical job where the person doing the work has been taken to court for not registering the work, only when the work was sub-standard have there been court cases. There have been court cases where the work was registered and it was sub-standard, so it's all about having good work done, in real terms you can forget the law as long as it is safe. The only time not having work registered is a problem is when selling or renting the house.

Because one there was a time constraint, and two I thought I may need to rent this house, when I wanted it rewired I employed a firm who were scheme members so I have all the paperwork, then I went around correcting some of the work. In theory all work is registered, yet when my father-in-laws house was sold, solicitors asked us for paperwork, I would have expected them to have asked county council as then sure it has not been altered in any way.

When new paperwork was issued where my son worked, he had not realised how it had changed so in error wrote the readings into wrong box for a row of houses on an estate, nothing wrong with installation, but as a result of the mistake paperwork showed they all failed, no one noticed, not the companies main office, not the scheme provider, not the county council, so what was the point in submitting the paperwork?

 

[EFLImpudence]

Again you are confusing two (or more) different things.

Part P has nothing to do with notification nor scheme membersip.

 

[SimonH2]

I looked at the Blagdon product, and the flaw was in the main you needed to remove the plug and refit it in order to install it, so it was uncertain as to if it complied with the letter of the law.
The idea was you could buy ready made kitchen stuff made in modules and simply plug and play, I don't think the pre-assembled rule was really for garden stuff, however the law is so poorly written it is hard to work out exactly what is permitted, reading the law, it seems you can make up and plug in an extension lead ...

I don't still have a copy of the BRs from that time, but as far as I can tell from a search (reference in an approved document) the wording was "Prefabricated equipment sets and associated flexible leads with integral plug and socket connections". Could you claim home makde stuff met that description ? Grey area, and I suspect you'd have an uphill struggle if it came to it.
Merriam Webster says prefabricate means "to fabricate the parts of at a factory so that construction consists mainly of assembling and uniting standardized parts" which would rule out home made one-off assemblies.