Part P installation quotes

[GaryinAshby]

Hi, I'm currently getting quotes for wiring my new extension and the prices (I've only had two so far) are miles apart! One was for £800 all in, the other was for £1400.

Before I get any more or ask questions, can you please advise me what I need to be specifically looking for from them?

A plan of the building is below, stating what is required in each room. I have the fans (& the holes have been knocked through for these), I have the shower & I also have all the cable required for ring mains, lighting & bonding (correct colour coding).

For the shower installation I have asked if the wiring can be taken from the MCB's & run along the outside of the house in conduit, entering the utility roofspace. Reason for this is that it will make life a lot easier as access under the floorspace in the house along that route is painfull mainly due to the upstairs bathroom floor being tiled.

Any comments on the quotes I have had & any other general guideance would be appreciated.

 

[oharaf]

All the circuits will need to have RCD protection, does your Consumer Unit have provision for this?

You don't mention Isolators for your extractor fans?

What power rating is your shower? What cable have you selected for the shower?

Running the supply in conduit will be fine, but, what sort of conduit are you intending to use?? PVC / Steel?

What distance is the 'run' for your shower?

I would say£800 is a GOOD price, but without seeing the job it is near inpossible to tell, the work involved could well push it toward the £1400 mark.

You need to ensure your sparky is a registered competent person.

Personal reccomendations are ofteh the best way

 

[GaryinAshby]

Thanks, at least I now have an idea of things to talk to the electricians about to get an idea of what is/isn't being done!

The CU was new in 1999, so I don't know whether RCD's could be fitted to it.
The extractors have pull cords, but I guess they need an additional isolator switch somewhere?
The shower is an 8kW, the cable run is approximately 15 feet. I have no cable for this, I was leaving this to the spark to sort (guessing 10mm T&E?)
No idea of conduit types, as there is little risk of impact in the area, I'd guess PVC would suffice?

 

[bongos]

The CU was new in 1999, so I don't know whether RCD's could be fitted to it

You may already have an RCD on it as the consumer unit would have been fitted to the 16th edition. If this is the case then you might be able to put some of the sockets on that RCD with RCBO's for other circuits. This will depend on how many spare ways you have on the existing setup.

It might be easier though to have a feed from this main board to a board in the extension. If you can post a pic of your existing setup it might give an idea of any remedial work may be required too.

 

[GaryinAshby]

Thanks for the help, see below:

The MCB's are, cooker, shower, ground floor ring, upstairs ring, kitchen ring, lights upstairs, lights downstairs & outside, garage. There are two spaces.

 

[oharaf]

You have no RCD on this board.

Bongos idea is a good suggestion, however by the time you've run the feed and purchased a second board you may be just as well replacing the current board with a Dual RCD board.

 

[TopTrumper]

He might have a rcd main switch

 

[Taylortwocities]

If he did then it would contravene 16th edition as the single RCD would be a single point of failure.

Maybe it is a TT with a separate 100mA RCD, somewhere, but even so the sockets would have to have a 30mA RCD on them.

So its a DIY consumer unit change done with a DIY cheapo board with no protection.
I agree, better, safer, more ompliant to remove it and put in an up to date board that meets the new requirements - well, most of them [/quote]

 

[GaryinAshby]

Thanks for all the advice, I now feel a bit more confident about what to expect to be done to comply.

 

[hairyben]

£800 seems impossibly cheap for the work involved. (Minimum 2 days Labour, materials, including cable, accessories, RCBO's)

£1400 seems more in line, but I'm thinking London money, things may be less in your neck of the woods.

Like others have said a consumer unit upgrade to dual RCD or better still, RCBO would make good sense.

Make sure your price includes an electrical installation certificate and notification to the building authority.