Hi Adrian. I've been a bit scarce recently, I've had a few contracts that we're finishing up with that have been keeping me very busy.

It's weird, I've been actively reducing the scope of my business over the last few years. I sold my fabrication shop, I offloaded the marine side of the business and various other enterprises and got down to just designing and building niche commercial/industrial control panels and board repair again which is where I started several decades ago. For some reason, rather than freeing up time as intended I've got progressively busier and I seem to be further away from slowly winding down into retirement than ever.

Anyway.....enough of my problems.

The installation needs to done under the supervision of a qualified sparky. This means in theory the work can be done by anybody as long as it's checked every step of the way or as long as the entire installation is accessible for inspection as well as testing after it's installed ie cabling is visible etc. You could arrange with your chosen eletrician that you photograph everything before the cabling becomes buried or concealed so realistically with a thorough catalogue of photographs only a few visits might be required during the installation for visual inspections. As circuits or areas of the installation are completed further visits would be required for testing before powering up.

I don't want to sound like I'm questioning your competence but generally I'd discourage people from installing their own electrics. As with any industry or trade there's numerous do's and dont's that often end up with DIY'ers making rookie errors which can become a big issue when the work needs certifying. Also there's much more subtle ways of doing things that have a profound effect on the general reliability of the installation, it's not things you can teach or forewarn about, it's just years of experience that mean when there's several ways a particular cat could be skinned an experienced sparky would know the best way or maybe why a particular way of installing something isn't suitable in that particular instance. Some of these tips and tricks are actually mentioned in the regs; how to make effective drip-loops at external cable entries is one that springs to mind but there are dozens of others that aren't specified.

Bottom line is you're definately going to need an electrician to test and certify so nominate one at the design stage and make sure you're both on the same page about who is going to do what. The worst thing you could do is just dive in and do the installing yourself and expect an electrician will just do a drive-by CoC after it's finished.