New Circuits from a shed DB

[NateCreekside]

Hi guys, I'd appreciate the opportunity to pick your brains a bit, and make sure I'm on the right track, please. (Will also be talking to my course tutor)
I'm currently studying for my NVQ lvl 3, and an opportunity has come up for me to do work which may be good for my portfolio.
I'm a landscaper, and on my current project, the client has asked for power to be run to two twin sockets in her new summer (3m2) house for a reading lamp, and a new PIR floodlight. The power would be from the existing (ancient, push in fuses, big separate rcd) DB in the garage.
There is already a radial with two twin sockets, and a 6amp circuit feeding a strip light.

I propose:
New board and circuits!
Going off Reg 433.1 in BBB. Garage is about 30m2, summer house 3m2
1 New Distribution Board, something like an MK 6-way garage unit (it needs to be metal?)
21 new radial, 20A, 2.5mm2 T/E (and 3-core 2.5mm SWA) total length approx 25m
Inside garage: 2x twin sockets, 1x 13a switch FCU for the tumble dryer (fitted with 13a plug)
then into a blank, through the wall into a wiska box for the SWA terminations.
Outside: spur off to an outdoor socket, continue to the summerhouse. Wiska box on the outside, through into a twin socket. also a spur out from the wiska to another socket, so no conduit is needed/on show inside the summer house.
3 Radial, 6A, 1.5 T/E. Keep the existing light, but have two-way switching, instead of just the one switch (two doors into the garage)
4 Radial 6A, 1.5 T/E. Install a PIR floodlight on the outside.
5 maybe put the roller shutter on it's own circuit? It's currently broken (tracks), but had been plugged into a socket. the installers have left a bit of the conductor insulation showing, and I feel like it needs to be made good.

T/E inside the garage will be in pvc conduit, SWA will be clipped direct to walls outside, and in flex conduit where buried.

The existing feed to the garage - haven't had a chance to examine the size of the conductors, yet, but it's on a 16A MCB on the board in the house. If I want to install a 20a radial, will I have to change the MCB? I think the existing radial is wired with a 20A. Again, I've been busy re landscaping the garden, and haven't had much of a chance to go poking around, yet.
And I assume the I should run an insulation resistance test the feed to the garage? Everything seems to be working okay, but daft just to assume.

Re building control:
I've got my 18th wiring, DEI cert and ECS card, but I still need to notify Building control PRIOR
as it is definitely notifiable.
I'm not on a registered skilled person (or am I?) so I need to appoint a third party who is. And they test and inspect my work, and complete the certificate etc, as laid out in 1.4 in the on site guide to building regs.
I've discussed all this with the client (who's brilliant), and she's agreed. I'm just fine tuning before I start pricing up.
Any thoughts? Anything I've missed?
Many thanks

 

[pc1966]

There are a lot of fuses for not many circuits there, apparently. Was it an ex-house fusebox reused?

Not sure why you are talking of a FCU for a tumble dryer with a 13A plug?!

The shutter door mechanism could go on a separate circuit for separation of faults, or just a FCU off the socket's circuit as the load is hardly an issue.

Otherwise not a bad idea to separate outside circuits from inside. Especially if you look at an RCBO style of board so any water-related tripping will not impact on the internal stuff.

As a general rule always go for metal CU. While there are some exceptions where the fire-resistant aspect need not apply it is easier just to use most common type available. And don't forget suitable glands (to maintain top of board sealing to IP4X) or at least grommits to protect cables on underside. But proper T&E glands are your most professional solution.

Yes, you should always test circuits for IR issues before proposing to reuse them. In many case 50+ year old PVC cable is perfectly serviceable for decades more, but in other cases recent cable might be damaged by various means (mice, crushing, contact with solvents, etc). Never assume that recent of currently working is going to be no-issue, check first!
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I can't answer about the Part P stuff out of simple ignorance, but other on here surely will know the answers.

 

[Taylortwocities]

Re building control:

This is where you can catch a cold. If you pitch up at LABC, as an individual, they will expect you to raise a building notice, for electrical works thats going to be about £230. LABC will want to inspect the works at various stages and expect it to be tested and certified to BS7671. Thats assuming you have a full set of calibrated test equipment.

Your better route (as you have said) will be to find a registered electrician who is agreeable to you doing a lot of the work overseen by him/her and who will do the final test. He/her can then notify the works through their CPS for a couple of quid. You'll also learn a lot from them.

Remember that the certification and notification process is meant to be done by the electrician who has DESIGNED, INSTALLED, and TESTED the whole enchilada. You'll have trouble finding someone to do the last bit if they have had no input to the process.

re

I'm not on a registered skilled person (or am I?)

No you are not. To do this you will need to join one of the CPS (NAPIT, NICEIC, etc). You'll need certain qualifications (the ones you have listed may be enough, but you need to check with your chosen scheme)
PLUS you'll need to go through a checking process which will include a check on at least one installation
PLUS you'll need a full set of calibrated test equipment
PLUS a copy of BS7671, GS38, HSE guidance, Public liability insurance of a couple of million
PLUS hand over several hundred pounds a year for the pleasure.

Its a necessary thing to do if you are making a go of domestic electrical work.

 

[NateCreekside]

TaylorTwoCities - oh yes, completely agree, that would be ideal, and realistically how it'll play out. I just need to find an electrician willing.
This whole plan of mine came from the clients request (once I'd already started work). I thought to myself "better run some conduit for an electrician, then." Then realised that it might be great for my portfolio.