Do not concern yourself re the shower pull cord.
- Provision of such is of direct benefit to you
- Fitters defence that it is not required under BS7671 is immaterial to the *evidence* of falsifying a BS7671 EIC!!
My point was regarding the fitters defence team
Just for the record, there are 2 schools of thought re shower isolators.
1. BS7671 does not require them (unlike Cookers).
In a TN-S/TN-C-S install an MCB is suitable for isolation if locked off (funny little clip & padlock), as is the CU mainswitch.
2. An isolator acts as an (accessible) junction box which i) adds terminals which can become loose (classic is live tightened twice, neutral tightened once) and ii) tempts bathroom fitters to run circuits off them using small size cable (say 1.5mm so it fits) which is not protected by the shower CPD (40A protecting 10mm shower cable).
Even if there is an isolator, you assume live until proven dead. Fluke Voltalert should be in every home, not an expensive item.
Re CU spare ways.
Not happy about the lack of spare ways, should really be 1-2.
It all reads like a rogue trader. Part P is specifically aimed to stamp them out, it was not actually intended to stop competent DIY until hijacked by word changing. That was as much done to stop traders claiming it to be DIY, later amended to add back competent DIY work (eg, time served qualified industrial sparks, elec eng or even C&G lecturers).
So you should get a good resolution with T/S involvement.