Build a houseextension - Extension electricals

I am annoyed about one thing; even though I've been a Fellow of the IEE for over 20 years I cannot sign-off the electrics I plan to install because I'm not 'certified' as required by new government regulations. I'm going to have to find an electrician to connect the consumer unit to the mains power and certify and test the work. Hummppff...

Wednesday, 13th June: I've bought a Wylex five way RCD (Residual-current device) consumer unit. I've selected an RCD unit as it will feed electrics in the garden to my work shed and my Japanese Teahouse.

There will be five circuits driven by separate MCBs ( Miniature Circuit Breakers).

6 Amp: Lighting in the extension.
16Amp: 13 Amp ring in the extension
16Amp: 13 Amp feed to the garden
50 Amp: Shower

I will feed the extension from the house using 10mm²cable which is rated at 240 volt @ 64 Amps.

Friday, 22nd June: I've temporarily placed the consumer unit on a noggin at the top of the stud wall.
Saturday, 23rd June: The skip company came and picked up the skip. At long last all the debris is gone and the garden is beginning to resemble normality.

Monday, 2nd July: I've managed to find an electrician who will come round to certify my wiring on the 17th July so I've made a start by bonding the metalwork in the utility and shower rooms to to the earth in the consumer unit.

Tuesday, 4th July: I started wiring today.

Here are the 13 amp sockets for the utility room.

The two at the bottom will be below the work surface.

These are not in their final place as the plasterboard still needs to be fitted.

The sockets are mounted in dry-lining boxes.

I don't know about you, I can never get those cable clips that use small nails to work with concrete or hard bricks without the nails bending.

I came across these great clips for fixing cables. You drill an 8mm hole, push them is and use a small cable tie. So easy!

I installed a combined shower light and extraction fan.
The extraction fan is placed above the ceiling with the vent pipe going to the outside soffit panel.

I fitted this before plasterboarding the ceiling by cutting away some of the insulation (but I forgot to photograph this).

This is the utility light switch. This has been wired as a two-way switch with an existing switch in the kitchen.
The sockets have been wired up to the consumer unit with a temporary power feed.

Monday, 9th July: Today was an interesting day; a bit of plumbing, a bit of electrics, a bit of painting and a bit of woodwork.

The consumer unit is pretty much wired up now to a temporary supply from the house. Everything seems to be in order.

Tuesday, 24th July: The electrician came round today and connected the extension electrics to the house mains supply.

This is my old electrics. The mains feed was installed in 1932 and upgraded in the 60s.

The consumer unit really needs replacing I guess!

Anyway, we added in the new two-way consumer unit that contains the 100 Amp isolating switch and the 50 Amp MCB to on the mains extension to the extension.

We also upgraded the cabling to the consumer units with 16mm cable as required with current regulations.

Everything seems to work!

He will come back on Friday to test the electrics and provide me with a compliance certificate for the Building regulations Surveyor.
Current regulations also call for earthing any metal work in the shower room so I have added earthing clips to the both radiators and the sink pipes. These are taken back to the extension consumer unit.

I also added a 16 Amp pull-cord isolating switch to the shower unit.

This was a right pig to wire as the 10mm cable is not easy to bend in the confines of the small box. The electrician suggested I use a 45mm deep box rather than the standard 32mm one - this made things a little easier.

Friday, 27th July: The electrician came around this afternoon and tested the electrics. All was OK and he will send me the certificate (and the bill!) on Monday. I am amazed at the number of forms he needs to complete...

So all the electrics are now completed.

Friday, 2nd August: I received the certification to BS 7691 certificate today, so the electrics are really finished. The Building Regulations Inspector will be happy!

I now have received the NAPIT certificate ready for the Building Regulations Surveyor.

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