UK Regulations - All fixed wiring

Still working through some of this, so it may change....


The reason for this post is that any fixed electrical installation in the UK below 1500V DC is covered, no exemptions, however the way to deal with this situation will be explained. No, you don't need a certified electrician to carry out work under Part P......

All battery builds that have any 'fixed wiiring' in the UK are covered by various regulations, regardless even if they are only 12V....... this includes hooking up an inverter that onlysupplies a separate 'off-grid' (non grid syncronised) circuit.


Electrical regulations are something that is not very well understood because of all the variations in each country and multitude of regulations added on top of other regulations that are then added onto again. Some "standards" are also just that and not legally binding with any statutory instrument / instrument of law.

Separately this mountain of regulation then becomes like a stack of cards with points that are completely unintended legal consequences, gaps or open to application in a way not originally intended but fully legal. The financial system is full of them more commonly known as 'tax loopholes' and it is quite ammusing for a UK tax return to now ask for participation in tax avoidance schemes. Don't correct the mountain of regulation, just apply a sticking plaster, "honest guv".


Anyhow, Part P was the change that appeared to stop home DIY from any eletrical work beyond simple items (or not so simple in actuality just a poor implementation), or does it.....


Part P of the building regulations 2010 (2214) is the legal instrument to now 'catch' electrical installations in the UK and specifically states 'intended to operate at low or extra-low voltage' and the definition of 'extra-low voltage' is less than 120V DC (or less than 50V AC). This then covers any battery build, even if it is 12V DC if it contains any fixed wiring. Low voltage is less than 1500V DC.

Part P, clearly states 'reasonable provisions shall be made in the design and installation of electrical installations in order to protect persons operating, maintaining or altering the installation fform fire or injury'. i.e. reasonable provisions to protect people in a house using the electrical parts. - i.e. Part P is for Health and Safety but does not stipulate specific explicit standards to apply at this stage.

The second section of Part P then covers :

(a) 'in or attached to a dwelling' - i.e. solar panels fixed to the the roof or your inverter fixed to the wall connected to fixed 240V wiring.

(d) 'in a garden or in or on land associated with a building where the electricity is from a source located within or shared with a dwelling' - this is more interesting regarding the source 'shared with' because this would then cover a grid inverter (solar or battery) and an inverter in the shed sharing the electrical wiring.

Part P does not, however stipulate any specific standards and instead relies upon the legal application of the word 'reasonable' (more to follow).


The only specific general exclusion is under Schedule 4 for 'telephone wiring or extra-low voltage wiring for the purpose of communications, information technology, signalling, contreol and similar purpose.' This is so that your internet cable is excluded if it has power over ethernet for example. So, no, battery builds are not actually excluded if they have any fixed wiring.....

You might want to amend your essay to reflect the fact thatPart P is not relevant for the entire United Kingdom.

True, the above 'essay' relates specifically to 'England and Wales'.

The Building Regulations (Nothern Ireland) 2012 (192) has electrical excluded.

The Building (Scotland) Regulations 2004 electrical is covered under 4.5 but does not have the same explicit Part P constraints as England and Wales in relation to planning and self certification exemptions overhead.

Is there a reason that they are so vague in their statements of the regulation?

I think the definition of reasonable should be that you take your own risks into your own hands, and that if you want to have certification or insurance, you have to be evaluated fairly in your aptitudes and builds for low voltage DC systems(240V DC max output and lower.)

Usual legal wording. The way 'reasonable' is used is how it is legally interpretated in relation as to what the current 'reasonable' safe standards are, i.e. 18th Edition Electrical wiring standards and the Health and Safety regulations, which also include the legal requirement for G83 (registering a 'type tested' grid connected inverter with the distribution company).

As long as you carry out work to the current wiring standards (and then retrospective apply for permission when required) this is within the rules as far as I understand, but not the real intention. Sort of like someone altering a house (say converting the loft) and than asking for retrospective planning where they have carried out all the work to the appropriate standards.

I would rule out any work that is not to the current wiring standards, they are there for a good reason. Life is short enough as it is, don't encourage it to be even shorter. I have seen all sorts of DIY wiring and the issues that can occur, even with good intentions at the time, because it is the unintended unexpected that always creates the issue.

In terms of 'certification' this is the 'self-certified' ticket to allow an installation to bypass a planning application under the Building Regulations, that's all. I have in the past done many periodic site inspections and they are like the dated signature on your consumer unit, however they are relatively superficial as you can't check what you can't see (wrong cable running through 2ft of rockwool) and each bend of a copper wire for testing embrittles them. One site we had to leave disconnected because the rubber wiring once disconnected for testing just crumbled away and you could not make it safe again as it just fell off the wire, iwthout movement it might have lasted another 50 years and equally burnt the house down the next day.


What I really dissagree with is that the IEE wiring standards are not a free and open publication, so it creates a legal conundrum which I don't think has not been properly legally challenged from a true DIY perspective yet. It's appliying a legal statute law (open public document) against a private paid for publication standard that is then interpreted as the 'reasonable' standard. i.e. you have to pay to find out what the law actually requires as 'reasonable'. This seems to be a common issue with a lot of country standards.

Imagine passing your driving test and then get asked for say 50 to find out what the speed limits are on particular roads....

completelycharged said:

Usual legal wording. The way 'reasonable' is used is how it is legally interpretated in relation as to what the current 'reasonable' safe standards are, i.e. 18th Edition Electrical wiring standards and the Health and Safety regulations, which also include the legal requirement for G83 (registering a 'type tested' grid connected inverter with the distribution company).

As long as you carry out work to the current wiring standards (and then retrospective apply for permission when required) this is within the rules as far as I understand, but not the real intention. Sort of like someone altering a house (say converting the loft) and than asking for retrospective planning where they have carried out all the work to the appropriate standards.

I would rule out any work that is not to the current wiring standards, they are there for a good reason. Life is short enough as it is, don't encourage it to be even shorter. I have seen all sorts of DIY wiring and the issues that can occur, even with good intentions at the time, because it is the unintended unexpected that always creates the issue.

In terms of 'certification' this is the 'self-certified' ticket to allow an installation to bypass a planning application under the Building Regulations, that's all. I have in the past done many periodic site inspections and they are like the dated signature on your consumer unit, however they are relatively superficial as you can't check what you can't see (wrong cable running through 2ft of rockwool) and each bend of a copper wire for testing embrittles them. One site we had to leave disconnected because the rubber wiring once disconnected for testing just crumbled away and you could not make it safe again as it just fell off the wire, iwthout movement it might have lasted another 50 years and equally burnt the house down the next day.


What I really dissagree with is that the IEE wiring standards are not a free and open publication, so it creates a legal conundrum which I don't think has not been properly legally challenged from a true DIY perspective yet. It's appliying a legal statute law (open public document) against a private paid for publication standard that is then interpreted as the 'reasonable' standard. i.e. you have to pay to find out what the law actually requires as 'reasonable'. This seems to be a common issue with a lot of country standards.

Imagine passing your driving test and then get asked for say 50 to find out what the speed limits are on particular roads....

Click to expand...

I agree with you 110%completelycharged . In Ohio USA your permitted to use steel conduit as a ground instead of a ground wire .

I totally disagree with that , over time it can become loose and rusty over time. I do not have a problem doing it to code ,


Big brother just wants more money and control . Having the job inspected is good to have a second set of eyes on to
make sure that didn't miss anything ,is good.