Loft conversion advice

[Nexus04]

Hello everyone,
let me begin by stating I am a homeowner after some advice and will in no way be attempting any electrical work my self. We are considering having our loft converted into a bedroom with en suite bathroom.
I would like some advice so when I am getting quotes I can make sure I am not having unnecessary work done and can ask for the best advice.
So our house is an average sized semi detached. So I would presume that the bedroom would have between 4 to 6 double switched sockets. led down lights in the bedroom and shower/bathroom. An extractor fan and shaver socket in the bathroom and a under floor heat mat in the bathroom. This would only have to be about 1 metre square. Now could the sockets and lights be wired by using the existing upstairs ring for sockets and the same again for the lights? And can the bathroom extractor run off the lighting circuit? I presume it can as it would switch on when the light is turned on and would switch off on a timer after the light is switched off. And could the underfloor heating run off a fused spur from the socket ring.
Just to add the consumer unit under the stairs is fairly new. It was changed when we had an extension 5 years ago and it has space for another 2 breakers in, but I would think it would be a pain to run a new feed to another smaller consumer unit in the loft extension. Or is this the way it should be done?
Is there anything else I should consider electrical wise or does that just about cover it?
Any input and advice will be greatly appreciated.

 

[Dustydazzler]

Mains smoke detectors on each floor and some 2way lighting on the new stairs

I recently did a new single bedroom loft for a builder and the total electrical bill came to £1450 (didnt require any new circuits)

 

[Nexus04]

Thanks for the swift reply. I forgot about the smoke detectors and the lighting for the stairs. But these can all be run from existing circuits? I presume whoever we get to do the conversion they will have an electrician on the team or a trusted subby that they use. I just want to ask the right questions when I am getting quotes

 

[SJD]

I presume whoever we get to do the conversion they will have an electrician on the team or a trusted subby that they use. I just want to ask the right questions when I am getting quotes

I wouldn't presume that at all, after the number of times I've seen the appalling state of wiring done by the builders so-called 'electrician'.

 

[Dustydazzler]

Builders ‘electriciano’ you mean the painter decorator or even the plumber with his sparky hat on

 

[James]

Remember to insist that ALL ELECTRICAL WORK has an electrical installation certificate.
it is likely to be a legal requirement anyway but just ensure it is in your contract with the builder.
try to hold on to a small percentage of the bill as final payment when all certificates and approvals are provided.

 

[telectrix]

several professional members here are based in the south east/ maybe one of them could quote for the electrics, when they can get their arses out of the fake tanning salon.??

 

[Dustydazzler]

several professional members here are based in the south east/ maybe one of them could quote for the electrics, when they can get their arses out of the fake tanning salon.??

Tel , tanning is always on a Tuesday , I was having my roots done today

on a series note if the OP is in Surrey i could take a look and give an estimate

 

[Nexus04]

Hi again everyone, thanks for the wise words. Dont worry I will be insisting on a proper test certificate and will be holding back a payment at the end until all snagging has been done to my satisfaction. I have learnt my lesson from having an extension done a few years ago. I am pretty sure I was more clued up about electrics than the 2 guys the builder used. I had to show one of them that you can get a 3 switch grid for a double gang back box!

Anyway I am digressing. So basically there is no real need to have a new run from the consumer unit downstairs everything can be installed from the existing upstairs ring and lighting circuits?

 

[Nexus04]

Oh @Dustydazzler I am in Kent but thanks for the offer it is much appreciated!

 

[DefyG]

So basically there is no real need to have a new run from the consumer unit downstairs

Doesn't sound like it from you've described and if the CU is only 5 years old 'presumably' the earthing/bonding was checked and upgraded if necessary then?
The CU if 5 years old probably wont be 18th edition and the sparks may want to upgrade that too, especially as under a staircase (Wooden)? damaged or IP rating impaired, but if properly MCB/RCD protected then it should be fine for continued use (unless evidence of thermal damage).
Ceiling construction/insulation may determine if possible to install recessed lights (building inspector will probably advise).
6 (double) sockets is generally a bit OTT for a bedroom.
The UFH will only be about 200w (max) so should be ok off existing circuits.

Any existing wiring may need re-routing if in 'the way' which will add time and therefore cost.
Any aerial cabling/amplifier in attic (often overlooked)!

 

[Dartlec]

Hi again everyone, thanks for the wise words. Dont worry I will be insisting on a proper test certificate and will be holding back a payment at the end until all snagging has been done to my satisfaction. I have learnt my lesson from having an extension done a few years ago. I am pretty sure I was more clued up about electrics than the 2 guys the builder used. I had to show one of them that you can get a 3 switch grid for a double gang back box!

Anyway I am digressing. So basically there is no real need to have a new run from the consumer unit downstairs everything can be installed from the existing upstairs ring and lighting circuits?

You are probably going to be fine taking off existing circuits, though that will depend on how they are currently wired, loading, etc - and that existing circuits are RCD protected - as new ones will need to be.

There are sometimes benefits in running new circuits - in that it avoids nuisance tripping - but the extra cost may outweigh the benefits...

I would advise coming up with a clear 'spec' of what you will need (number of sockets, lights, etc) and use that to get a quotation from the builder for the electrical parts, but perhaps also obtain quotes from other electricans to compare.

If you do use the builder, check that the electrician they will use is Part P registered so that the relevant parts of the new work will be notified to the council.

If the builder is reputable and using a genuine electrician there can be benefits, as they will liaise between themselves to get wiring in at the relevant stages, etc. Otherwise you may end up having to do some project management yourself, ensuring that the electrician is on site at the right times to get wiring in before other work can be completed, and avoiding any hold ups if timescales change as they often do due to material delays, etc.

 

[Nexus04]

Hello again,

many thanks to all who have taken the time to reply. This is very much in the planning stage at the moment but I am grateful for the advice given here. At least when I am getting quotes I know what questions to ask. I am pretty sure that an electrician would be able to extend the existing upstairs circuits as we have got one double socket in each bedroom so adding a few in the loft should not be a problem.
The existing consumer unit is metal and made by Eaton and has RCD`s and is just coming up to being 5 years old. Incidentally when I do have the work done I will be having the aerial upgraded and new aerial points in each bedroom, so its another thing to think of where to put the amplifier/splitter when the work gets done. Thanks to DefyG for mentioning that.
Whoever we use I will make sure they are part P registered and can issue all the relevant certificates and notification to the council and building inspector etc.