domestic circuit testing and regulations

[officer dibble]

I have just had a kitchen extension plus one living room built which will require wiring. In the original house there is a wire-fused consumer unit (no rcds) and an additional one for the last extension built in the 80's(no rcd but mcbs). My builder has advised me to have a single modern consumer unit fitted to service the entire house and extensions. My problem is that the original house was built in the 1960's and does not conform to modern regulations.It has ring mains and pvc cable but in grey sheathed black and red cable and the sockets don't have earth sleeves ( I could have all the sockets replaced and this remedied though). I don't know whether it will require completely rewiring to meet modern regulations even though the wiring "seems" fine.The 80s CU could service the new extension at by extending the ring mains and lighting circuit. I need advice on whether to go for a single modern consumer unit
or
add an rcd and mcbs to the 60's CU and add a separate rcd to the 80's CU which will serve the newest extension as well and have this CU tested for IET compliance
or
upgrade as mentioned before but one rcd for both existing CUs' (which needs doing anyway for safety reasons) but have yet another CU fitted which will only service the newest extension but is certain to pass all current IET regulations.
I don't want to fall foul of modern regulations and pay for a complete house rewire as the existing circuits are still servicable and should have passed regulations at the time of installation.
I would welcome any advice.

 

[Des 56]

If any modifications have been made,they should have been done in such a way as to comply with the regs at the time of installation

However,you and I know that alterations are often done by the householder or the cheap jobber who may know nothing of doing the job in such a way as to prevent danger,both to property via a fire, or shock to a person using the installation
That's because in their mind,if something works,"Hey what more could there be to consider,it works,don't it"

When you have an inspection,if the Guy doing the inspection is an electrician who is competent and qualified to carry out this work (many are not)then anything that is either dangerous or a fire hazzard will be highlighted

If that were the case,would you not be more concerned that you have become aware that part of the installation has been identified and brought to your attention rather than a satisfactory signature for a possible hazzardous installation by a numpty inspector giving a rouge satisfactory signature on a bit of useless paper
Remember to be aware,there are many large national companies and some small companies who are registered scheme members mainly, doing pretend inspections who will provide this service at very cheap rates,so beware of large firms doing inspections and extra cheap others

Do not be over pessimistic about older parts of the installation.safe wiring was around long before the present edition of the regulations

Get your inspection done,by an individual who can produce evidence of his own competence and don't be suckered in by scheme membership where the person doing the inspection may be well short of being competent

The probability is that the existing installation,if it has not had too much potching done,may surprise you regards its safe continued use

 

[malcolmsanford]

If an old installation such as mine has been modified say by the addition of a spur to the ring main at some point, what impact does this have on compliance

Des56 eloquently summed up the situation in post # 16 and to be honest there is not more that can be added.

I can only really reiterate that there are many installation in the UK that are 50-60 yrs old and have been added to over their life span.

It is so difficult for a customer to identify, in any trade, who is good who is bad. I would like Des advised, that to choose someone that is competent I always felt that the more professional they are and the more they explained tings to someone in simple terms meant they had a fair grasp on their profession.

As for this hypothetical spur off of an existing RFC, the tester will use his knowledge and expertise to advise you if it is safe for continued use, and that is what an Electrical Installation Condition Report is, it is to ascertain if your installation is safe, not that it fails the current regulations because logically any installation pre 2008 will most likely not come up to the current regulations, but it does not mean it is unsatisfactory or unsafe