This best practice guide is a good start. It will give you an idea. However it is a professional opinion and two electricians will find different things. And it is also down to the remit.
I have seen so many times, where one electrician does installation and another does portable appliance testing and neither tests the hand drier in the toilet. It should be done as appliance testing, but it's not portable.
So some one has to say what they want, it took three electricians three days to inspect and test one portable appliance, OK it was a batching plant and it was transported with 22 attic units. But it was not fixed and it was an appliance not the installation. And the foreman had issued check sheets showing exactly what needed testing and inspecting.
As to codes it is up to the electrician and having asbestos in a fuse carrier will be ignored by one, given C2 by another and F1 by another as they will refuse to remove the fuse carrier to check. And with re-wireable fuses one has to consider the status of the person in charge, ordinary, instructed or skilled. So in two identical premises in one OK in the other C3 just because of status of person in charge.
In the main it is a get out of jail free card, and electricians know too many items raised and they will not get return work, and they use tactics to shift blame. So one cable with some cores showing going into a box, and they class whole box C3 this means some one should correct it, and when they do a minor works certificate will show its been done, so then over rides the EICR. So if the electrician can find a fault, then he has passed on the responsibility to some one else.
I know it should not happen, but I have seen reports where one has no idea what has been seen as a fault, page 6 shows "Inadequate provision of socket-outlets" that could change 5 minutes after the inspection, so you get an inspection done, then you get an electrician to correct things, and he is left scratching his head wondering why its been coded. If the BS7671 reference number is used i.e. 422.4.2 then one has an idea, in that case one is looking at fire risk as light too close to combustible material, (that may have changed as I am using an old copy of BS7671) but point is simply DB1 Code 2 is not good enough, and some firms leave it open so they can use it as their get out of jail free card.
So what you need is a contract with some one to maintain your electrical installation and equipment. As a non technical person that is really the only option. Since nothing marked, they could not give you a quote, it would be day rate. I remember doing a Bank, there were borrowed neutrals and all sorts of problems, but to look at before starting it seemed easy, if some one gives you a quote, then likely it is on win some loss some idea, some large firms do this, like British Gas, or it's tick the box and run. What you really want is some one when they come across a small fault they fix it, rather than produce a list which needs actioning latter.
