An Installation designed in 2018 to BS7671:2008 (2015) 17th edition and constructed in 2019 (BS7671:2018 18th edition), has to be verified against the current standard?
Just my thoughts and not a definitive answer, but it seems to me this is a contractual matter rather than a legal matter, so it depends what the contract says. If the contract specified that the installation should be designed and installed to the 17th edition then it needs to be tested to the 17th edition to show it is in accordance with the contract. If the individual testing it is there to show compliance with the contract then he/she should test it to the 17th edition, but if he/she has been just asked to provide a certificate for the installation then I would imagine testing it against the 18th edition is appropriate.
Of course it is even more complex if the contract does not specify the edition, but I won't go there.
It can be designed to one edition, then installed then tested to that one edition and it passes (or fails) on that as an installation.
Subsequent periodic inspections including testing (which could be one day later than the above) must be carried out by refering to regs at the time of the periodic (EICR) so passes or fails on that.
Agreed - initial verification (as with construction) should be based on the design - and signed off on the same certificate as the design & construction - so all need to be based on the same version of the regs (otherwise things rapidly get very silly).
Subsequent periodic inspection need of course to be based on the regs at the time of those inspections, but that's a separate matter.
